Jos Buttler hits a blistering 83 from 45 balls as England cruise to a seven-wicket win over West Indies in the second T20.

Lizelle Lee sets a new record for the highest individual score in the Women's Big Bash League with 150 not out for Hobart Hurricanes.

The journey of this year's tree from the West Midlands to the West End ahead of tonight's switch on.

The princess has begun to return to some public duties since finishing chemotherapy in September.

1. NASA Alert: Massive 'God of Chaos' Asteroid Apophis Makes Closest Pass by Earth Yet  Bizz Buzz
2. NASA alert! 'God of Chaos' asteroid approaching Earth on November 13 sparks worldwide concern  The Times of India
3. Nasa Alert: Massive 'God of Chaos' asteroid Apophis nears earth in closest pass yet  CNBCTV18
4. Giant Meteorite To Hit Earth On November 13? What We Know  News18
5. 'Astonishingly close': A colossal space rock could wreak havoc on Earth in 2029  Business Today

A military judge has canceled the Biden administration’s attempt to hand a plea deal to Khalid Sheikh Mohammed and two other terrorists who Biden wanted to give a lighter sentence. Biden Defense Secretary Lloyd Austin had tried to make a plea deal with the terrorists that ran against their previous sentences by allowing them to […]

The post Military Judge Cancels Biden’s Attempt to Give Aid to Terror Masterminds of 9-11 appeared first on The Lid.

Two of the worst fake news purveyors, MSNBC and CNN, both suffered ratings bloodbaths since Donald Trump won his historic victory last week. And it couldn’t happen to any more serving networks. Let’s take the extremist, left-wing MSNBC. Take a look at this delicious drop in ratings: Major Nielsen ratings plunge at MSNBC since Trump […]

The post Fake News MSNBC, CNN Ratings Collapse after Trump’s Massive Win appeared first on The Lid.

Continuing to set records, Pepe Unchained recently achieved a new milestone after reaching $26 million. The project’s presale has now… Continue reading As Pepe Unchained Launch Date Nears, Analyst Makes ‘Massive’ Prediction For PEPU

The post As Pepe Unchained Launch Date Nears, Analyst Makes ‘Massive’ Prediction For PEPU appeared first on ReadWrite.

A North Texas man recently spent $4000 on a guitar he believed was signed by Taylor Swift at the Ellis County Wild Game Dinner in Waxahachie, Texas, and then immediately destroyed it with a hammer. Sounds like the guitar was an imposter. — Read the rest

The post Texas man wastes $4k smashing a Taylor Swift "themed" guitar appeared first on Boing Boing.

CNN reportedly will be making more cuts in the near future, including to its highly paid on-air personalities, following poor election ratings. The New York Post reported that Fox News […]

The post On-Air Talent Will Not Be Spared as CNN Prepares Mass Layoffs in Wake of Election: Report appeared first on The Western Journal.

Pro-Trump businessmen Elon Musk (the richest man in the world) and Vivek Ramaswamy have officially joined the incoming Trump administration. President-elect Donald Trump announced in a statement published Tuesday that […]

The post Breaking: Musk, Ramaswamy Officially Join Trump Administration - Their Job Is to Destroy Bureaucracy appeared first on The Western Journal.

An important mechanism of resistance to β-lactam antibiotics is via their β-lactamase–catalyzed hydrolysis. Recent work has shown that, in addition to the established hydrolysis products, the reaction of the class D nucleophilic serine β-lactamases (SBLs) with carbapenems also produces β-lactones. We report studies on the factors determining β-lactone formation by class D SBLs. We show that variations in hydrophobic residues at the active site of class D SBLs (i.e. Trp105, Val120, and Leu158, using OXA-48 numbering) impact on the relative levels of β-lactones and hydrolysis products formed. Some variants, i.e. the OXA-48 V120L and OXA-23 V128L variants, catalyze increased β-lactone formation compared with the WT enzymes. The results of kinetic and product studies reveal that variations of residues other than those directly involved in catalysis, including those arising from clinically observed mutations, can alter the reaction outcome of class D SBL catalysis. NMR studies show that some class D SBL variants catalyze formation of β-lactones from all clinically relevant carbapenems regardless of the presence or absence of a 1β-methyl substituent. Analysis of reported crystal structures for carbapenem-derived acyl-enzyme complexes reveals preferred conformations for hydrolysis and β-lactone formation. The observation of increased β-lactone formation by class D SBL variants, including the clinically observed carbapenemase OXA-48 V120L, supports the proposal that class D SBL-catalyzed rearrangement of β-lactams to β-lactones is important as a resistance mechanism.

Why burning biomass is not zero-carbon Explainer Video NCapeling 17 October 2022

Short animation explaining why burning biomass produces more carbon dioxide per unit of energy generated than almost all fossil fuels.

The climate emergency requires countries to transition away from fossil fuels, but it is important to be careful about the alternative energy sources chosen.

In particular, concern is growing over the use of biomass for energy, which is generated when wood or other plant material is burnt to generate heat and electricity. Many governments treat biomass energy as zero-carbon at the point of combustion, and subsidize it in the same way as renewables such as solar or wind, resulting in a large increase in the use of biomass for energy in the UK and the European Union (EU) over the past 15 years.

The treatment of biomass as zero-carbon in policy frameworks rests on the argument that biomass emissions will be reabsorbed by forest growth, particularly from trees planted to replace those cut down to burn.

But growing trees to maturity takes many years and, depending on the feedstock used, biomass burning increases global warming for decades to centuries. This is called the ‘carbon payback period’ – the time it takes for carbon dioxide levels to return to what they would have been if biomass had not been used.

New research from Chatham House and the Woodwell Climate Research Center calculated the real climate impact of burning US wood pellets in the UK and EU. In 2019, according to this analysis, US-sourced pellets burned for energy in the UK were responsible for between 13 million and 16 million tonnes of carbon dioxide, equivalent to the annual greenhouse gas emissions from 6-7 million passenger vehicles.

But because biomass is treated as zero-carbon, almost none of these emissions were included in the UK’s national greenhouse gas reports. And the removal of forest carbon from US forests is not included accurately in US reports, either.

Steven A. Carr
Mar 1, 2014; 13:907-917
Technological Innovation and Resources

Michal Bassani-Sternberg
Mar 1, 2015; 14:658-673
Research

Ivan Matic
Jan 1, 2008; 7:132-144
Research

Hasmik Keshishian
Dec 1, 2007; 6:2212-2229
Research

Yi Zhang
Sep 1, 2005; 4:1240-1250
Research

Amelia C. Peterson
Nov 1, 2012; 11:1475-1488
Technological Innovation and Resources

Guoan Chen
Apr 1, 2002; 1:304-313
Research

Leigh Anderson
Apr 1, 2006; 5:573-588
Research

Ignat V. Shilov
Sep 1, 2007; 6:1638-1655
Technology

Jesper V. Olsen
Dec 1, 2005; 4:2010-2021
Technology

Candida albicans and Aspergillus fumigatus are dangerous fungal pathogens with high morbidity and mortality, particularly in immunocompromised patients. Innate immune-mediated programmed cell death (pyroptosis, apoptosis, necroptosis) is an integral part of host defense against pathogens. Inflammasomes, which are canonically formed upstream of pyroptosis, have been characterized as key mediators of fungal sensing and drivers of proinflammatory responses. However, the specific cell death pathways and key upstream sensors activated in the context of Candida and Aspergillus infections are unknown. Here, we report that C. albicans and A. fumigatus infection induced inflammatory programmed cell death in the form of pyroptosis, apoptosis, and necroptosis (PANoptosis). Further, we identified the innate immune sensor Z-DNA binding protein 1 (ZBP1) as the apical sensor of fungal infection responsible for activating the inflammasome/pyroptosis, apoptosis, and necroptosis. The Zα2 domain of ZBP1 was required to promote this inflammasome activation and PANoptosis. Overall, our results demonstrate that C. albicans and A. fumigatus induce PANoptosis and that ZBP1 plays a vital role in inflammasome activation and PANoptosis in response to fungal pathogens.

Lys234 is one of the residues present in class A β-lactamases that is under selective pressure due to antibiotic use. Located adjacent to proton shuttle residue Ser130, it is suggested to play a role in proton transfer during catalysis of the antibiotics. The mechanism underpinning how substitutions in this position modulate inhibitor efficiency and substrate specificity leading to drug resistance is unclear. The K234R substitution identified in several inhibitor-resistant β-lactamase variants is associated with decreased potency of the inhibitor clavulanic acid, which is used in combination with amoxicillin to overcome β-lactamase–mediated antibiotic resistance. Here we show that for CTX-M-14 β-lactamase, whereas Lys234 is required for hydrolysis of cephalosporins such as cefotaxime, either lysine or arginine is sufficient for hydrolysis of ampicillin. Further, by determining the acylation and deacylation rates for cefotaxime hydrolysis, we show that both rates are fast, and neither is rate-limiting. The K234R substitution causes a 1500-fold decrease in the cefotaxime acylation rate but a 5-fold increase in kcat for ampicillin, suggesting that the K234R enzyme is a good penicillinase but a poor cephalosporinase due to slow acylation. Structural results suggest that the slow acylation by the K234R enzyme is due to a conformational change in Ser130, and this change also leads to decreased inhibition potency of clavulanic acid. Because other inhibitor resistance mutations also act through changes at Ser130 and such changes drastically reduce cephalosporin but not penicillin hydrolysis, we suggest that clavulanic acid paired with an oxyimino-cephalosporin rather than penicillin would impede the evolution of resistance.

Russia's end games and Putin's dilemmas Expert comment NCapeling 14 February 2022

As warnings from Washington and London intensify, the period of maximum danger in the Ukraine standoff has begun. Even if conflict is avoided, the status quo has gone.

There are several reasons to believe conflict over the Ukraine is imminent. The military build-up is complete. Russia has added tactical support elements, including medical units, to its already large and comprehensive array of troops and equipment deployed to the east, north, and south of Ukraine.

Additional naval units have entered the Black Sea, military exercises with Belarusian forces have begun and, along with those on Russian territory, these can all provide cover for an intervention of some sort.

Far from being comforting, comments by Vladimir Putin and his entourage that it will not be Russia provoking a conflict are ominous. Russian media has ramped up domestic programming about the ‘imminent Ukrainian fascist threat’ to the motherland. And a recent US intelligence briefing alleges sophisticated preparations by Russian intelligence include releasing a video of a staged attack on Russian-speaking civilians in northern Ukraine.

Should Russia attack, its ‘fortress economy’ could weather a new round of sanctions for several years, not least given the growth in Russia’s hard currency reserves to $630 billion, under 20 per cent of which are now held in US dollars, and the high demand for – and global price of – oil and gas.

What does Putin really want?

Diplomacy is in high gear but, as Putin and other senior Russian figures have made clear, the US and European offers of new security confidence-building measures do not address Russia’s two core, stated demands – namely to withdraw US and NATO forces close to its borders in former Soviet and Warsaw Pact states, and to end NATO’s ‘open door’ policy to future enlargement.

For the Kremlin, enlargement to Ukraine would remove a critical buffer between Russia and the NATO alliance. If Putin’s objective, therefore, was simply to put down an unambiguous marker that Ukrainian membership of NATO is a red line, he has made progress.

He has reminded the world and Ukraine’s leadership of that country’s strategic vulnerability. US president Joe Biden and his European counterparts have stated NATO will not commit forces to defend Ukraine if it is attacked. And although they remain resolute on the ‘open door’ policy, there have been reminders NATO does not accept new members who risk importing a pre-existing conflict into the alliance.

If another Putin objective was to refocus US and, to a lesser extent, European attention away from China and back onto Russia and its security interests, he has succeeded. NATO has offered some new confidence-building measures around the conduct of military exercises and deployment of forces, while the US may be willing to enter negotiations for a new treaty with Russia to limit nuclear missiles deployed in Europe.

This would mean setting aside the growing threat posed by Chinese missiles that had partly motivated the Donald Trump administration to withdraw unilaterally from the Intermediate-Range Nuclear Forces (INF) Treaty.

But there is another scenario to consider – that although these two issues are both important, neither are Putin’s core objective, which instead is to right once and for all the historical ‘wrong’ of Ukraine’s separation from Russia in 1991.

As Putin made clear in a lengthy essay in July 2021, he sees an independent, sovereign Ukraine as a historical aberration, and he blames the US for the deepening discord and animosity between ‘brotherly’ Ukraine and Russia.

Not stated in the essay is that the emergence of a more democratic and functional Ukraine poses an existential threat to Putin’s own control over Russia. In contrast, reincorporating Ukraine into a ‘greater Russia’ would underpin his now constitutionally-mandated opportunity to reign until 2036, as well as being his biggest legacy.

The problem is it seems impossible to bring Ukraine permanently back into Russia’s sphere of influence without some form of new military intervention.

Putin’s options

Putin’s strategy to date has been limited to ensuring the breakaway Ukrainian portions of Donetsk and Lugansk gain a legal right to block any future efforts by the central Ukrainian government to join either the European Union (EU) or NATO.

The Kremlin sees expansive interpretation and implementation of the 2014-15 Minsk protocols allowing self-governance for these areas currently under Russian military control as a potential route to this outcome. But for Volodomyr Zelensky or any future Ukrainian president to accept this would be political suicide, and Kyiv has already resisted French and German pressure to make this concession under the Normandy Format of meetings they share with Russia.

If Putin has now decided to undermine Ukrainian sovereignty more explicitly, he can order a limited military intervention further into these occupied territories – and perhaps areas adjacent to them and Crimea – under the pretext of ‘protecting’ Russian-speaking communities there.

This would be relatively easy to achieve and, combined with a blockade of Ukraine’s Black Sea ports, could successfully destabilize the government in Kyiv. But such steps would trigger international economic sanctions and drive Ukraine even further towards the West.

A 21st century ‘blitzkrieg’ to take Ukrainian territory as far as the Dnipro River including Kyiv and all points east, would come closer to achieving Putin’s territorial and historic legacy. And this is now a feasible option given Russia’s military superiority. But how easily Russia could then hold the territory and consolidate its political control would be doubtful, and these moves also bring high-risk, long-term economic and diplomatic costs to Russia and to him personally.

No return to the status quo

On balance, Russian military intervention in the coming days or weeks is still less rather than more likely. Putin may yet accept a new, visible, bilateral accommodation with the US on the future of European security.

Sinwar’s death does not make Hamas–Fatah reconciliation more likely, whoever his successor may be Expert comment jon.wallace 22 October 2024

The killing may aid Hamas recruitment – but it will not make agreement with Fatah any easier to achieve.

Western political leaders were quick to argue that Israel’s killing of Hamas leader Yahya Sinwar on 17 October presented an opportunity for a ceasefire in Gaza and the return of Israeli hostages.

US President Joe Biden immediately called on Israeli prime minister Benjamin Netanyahu to seize the moment to negotiate, now that Israel has achieved one of its war aims.

However, that ‘moment’ has already passed. Israel’s military assault on Gaza has intensified since Sinwar was killed, leading UN Peace Process Co-ordinator Tor Wennesland to say that ‘nowhere is safe in Gaza’. It is abundantly clear Netanyahu is intent on further degrading Hamas, resetting a new ‘power balance’ and carving out a buffer zone, no matter the cost in Palestinian lives or Israeli hostages. 

But there are other implications of Sinwar’s assassination beyond the zero-sum analysis of will there or won’t there be a ceasefire.

Hamas’s ability to fight

At present, everyone has an opinion on how Sinwar’s killing will affect Hamas and its ability to resist and respond to Israel’s military. His death will have been a major blow – symbolically, operationally, and psychologically. Hamas has been downgraded and its capacity to respond compromised.

But it will recover, regenerate and retaliate in time – and Sinwar’s death will have been no surprise to Palestinians in Gaza or elsewhere. Hamas is accustomed to seeing its leaders assassinated. Since its formation in 1987, it has been ‘decapitated’ many times, only to continue with its mission to ‘liberate Palestine’.

Hamas’s portrayal of Sinwar dying in his fatigues, head wrapped in a keffiyeh and resisting until the end will persuade many young Palestinians that he died as a martyr serving the Palestinian cause. Many will be inspired to join and fortify the ranks of Hamas as a result.

The IDF’s release of drone footage showing Sinwar’s last moments will have done nothing to undermine his credibility. 

On the contrary, it will serve as a rallying call to disaffected and disenfranchised young Palestinians horrified by Israel’s bombing of civilian targets in Gaza and disaffected with Fatah’s inability to prevent Israeli settler expansion and violence in the West Bank.

Reconciliation

Some hope that if Sinwar is replaced by a more ‘moderate’ leader, his killing may smooth the path to Hamas–Fatah reconciliation – and that this could provide a foundation for a patchwork political solution when Israel and Gaza arrive at the ‘day after.’  

But the idea that a downgraded and ‘leaderless’ Hamas will be susceptible to international pressure to reconcile with Fatah is divorced from reality.  

Prospective new Hamas leaders such as Khaled al Meshaal and Khalil al-Hayya are based in Qatar. 

They may be more pliable to external pressure to reconcile with Fatah in search of a political outcome, but their ability to influence events on the ground in Gaza will be limited. That was demonstrated by the Sinwar-orchestrated attacks on 7 October 2023, which took place without the blessing of the exiled leadership in Doha.

Hamas has long gone to ground in Gaza and become far more decentralized than it was before 7 October. It is now more typical of an insurgency, where Hamas cadres exercise a great degree of operational autonomy.

In other words, the disconnect between Hamas in Gaza and its political leadership in Qatar has only grown wider since this round of conflict started.

International efforts

That will undermine international efforts made by Qatar, Egypt, Saudi Arabia, China, Russia and others to bring about a reconciliation. Moscow and Beijing already hosted reconciliation talks in February and April early this year but made no progress in closing the chasm between the two parties. Saudi Arabia has also hosted talks.

The three Arab states, none of which have so far commented publicly on Sinwar’s killing, will likely view his death as an opportunity to bolster the political wing of Hamas – backing it with pledges of political, diplomatic and financial support.

Saudi Arabia and Egypt will have next to no influence over the succession process, but Qatar’s long-established relationship with the political wing of Hamas affords it leverage over the organization, albeit limited. They may be able to strengthen the hand of those based in Doha by promising to work harder at securing a ceasefire, guaranteeing the provision of humanitarian relief, and working towards a political solution.

Harris and Trump's shared goal masks a fundamental AI policy divide Expert comment rgold.drupal 3 November 2024

Both presidential candidates will pursue US tech dominance but differ on the means to achieve it.

There remain some differences between the US presidential candidates’ positions on the governance of artificial intelligence and other emerging technology, notably around competition. 

But under either future administration, US decision-making looks set to be heavily influenced by growing securitization, the aims of the US technology industry and broader competition with China. 

‘Safe’ AI development 

Vice President Kamala Harris attended the inaugural Global AI Safety summit in the UK in 2023, where she announced President Joe Biden’s Executive Order on AI. This significant move by the federal government sought to define national and cyber security guidelines for AI developers and outline privacy and transparency guarantees. It also committed the federal government to a review of the National Security implications of this emerging technology, which was published last week.

In her remarks at the summit, Harris was clear that her definitions of safety extended beyond catastrophic risk mitigation to societal and personal harm. She noted the corrosive effects of some algorithmic decision-making and disinformation on democracy, appealing for AI that is developed ‘in the service of the public interest’.

A number of initiatives developed during the Biden administration have attempted to steer emerging technology as it takes root in society. This includes the establishment of the US AI Safety Institute, various schemes on global AI governance and investment in Public AI projects like the National AI Research Resource (NAIRR).

The US public is largely supportive: polling by the AI Policy Institute (AIPI) points to a majority preference for safety standards governing the US effort to lead in AI, rather than pedal-to-the-metal development. Investment in public options on AI and the infrastructure required to develop and sustain it is a bold direction that the incoming administration should consider expanding.

Biden’s Executive Order on AI has come under fire by the Trump campaign. At a rally in Iowa, Trump explained that he would cancel the order ‘on day one’, echoing a Republican platform that described it as imposing ‘Radical Leftwing ideas’ . 

Trump does, however, have his own track record in technology policy. During his first presidency, his administration passed an Executive Order on AI, stressing that ‘continued American leadership in Artificial Intelligence is of paramount importance to maintaining the economic and national security of the United States’. The tools and institutions announced as part of the order – including AI research investment, national AI research institutes and AI regulatory guidance including on federal use of AI – echo those of the current administration. 

Four years is a long time in AI, however. As the power of this technology is revealed, talk of safety may give way to talk of security. While the candidates may disagree on the role of the federal government in setting standards, there will be close alignment on the central need for US supremacy in national security. Neither administration seems likely to erect barriers to securitization of AI should it emerge as a critical strategic asset.

AI regulation at home 

American industry will remain the pivotal force shaping the US AI ecosystem, particularly as America jostles for position as the maker of the global rules governing AI. A notable aspect of Biden’s AI Executive Order was where it staked responsibility. Reports by AI and Cloud companies on the safety of their tools and infrastructure are sent to the Department of Commerce.

Under Secretary Gina Raimondo, whose star continues to rise, the department has become significantly more engaged with technology companies. In the absence of any other legal authority, AI governance has therefore sat under the purview of a secretary who herself has noted that they are ‘not a regulator’. 

The trend of industry leaders driving the government agenda on AI is replicated in other departments. There was an outcry over the composition of the new Department of Homeland Security advisory panel, the Artificial Intelligence and Security Board, with civil society groups concerned about the preponderance of industry voices: the 22-member panel includes the CEOs of OpenAI, Anthropic, NVIDIA, IBM, AWS, Adobe, Microsoft and Alphabet.

Under a Harris presidency, these trends seem likely to continue. Plus with deadlock in Congress probable, establishing new legal authorities for emerging technology will be difficult. That will likely mean emerging tech governance remains heavily influenced by the Department for Commerce. 

Like Harris, Trump has his allies in industry. While the Biden administration has courted the CEOs of AI companies who have historically spoken out in favour of regulation, Trump’s allies tend towards a more deregulatory agenda. 

Silicon Valley billionaires Elon Musk and Marc Andreessen have backed Trump’s plans to minimize AI regulation, lauding his support for ‘little tech’. They have also backed reported plans for so-called ‘Manhattan Projects’ to develop military technology, stewarded by ‘industry-led’ agencies. Trump’s aversion to strong regulatory institutions may mean an end to Biden’s anti-trust efforts, benefitting the biggest voices in the room, though his VP pick may disagree. JD Vance has somewhat surprisingly come out strongly in defence of the current chair of the Federal Trade Commission, Lina Khan, and her anti-trust efforts targeting US big tech.

Regardless, business interests will likely shape either a Harris or Trump administration’s approach as the US grapples with balancing the ambitions of its industry with an increasingly protectionist stance towards its biggest import market, China.

Competition abroad

China looms large in the imaginations of both campaigns. 

The US has signalled to its allies that American AI standards should replace Chinese standards. Export controls on semiconductors were expanded in September this year, with key voices in the industry – notably the Netherlands, Japan and South Korea – describing the restrictions as ‘economically motivated’ despite nominally being tied to national security by the US. 

Members’ Christmas drinks 11 December 2024 — 6:00PM TO 8:00PM Anonymous (not verified) 11 November 2024 Chatham House

Join us at 10 St James’s Square for a chance to raise a glass with fellow Chatham House members and staff.

This evening is a special opportunity to meet fellow Chatham House members and staff around the Christmas tree.

Please note this reception is open to members of Chatham House only. Regrettably, we are unable to register non-member guests.

The institute occupies a position of respect and trust, and is committed to fostering inclusive dialogue at all events. Event attendees are expected to uphold this by adhering to our code of conduct.

Dr. Abiy Tasissa of Tufts University, discusses the mathematics he and colleagues used to study particle collider data, including optimal transport and optimization. Collider physics often result in distributions referred to as jets. Dr. Tasissa and his team used "Earth Mover's Distance" and other mathematical tools to study the shape of jets. "It is interesting for me to see how mathematics can be applied to study these fundamental problems answering fundamental equations in physics, not only at the level of formulating new ideas, which is, in this particular case, a notion of distance, but also how the importance of designing fast optimization algorithms to be able to actually compute these distances," says Dr. Tasissa.

Simone Cecchini and Rudolf Zeidler
Trans. Amer. Math. Soc. 377 (), 5271-5288.
Abstract, references and article information

Luiz Ricardo Abreu Melo
Proc. Amer. Math. Soc. 152 (), 5373-5380.
Abstract, references and article information

NEW YORK (AP): The Rockefeller Center Christmas tree arrived in New York City on Saturday, signalling the start of the holiday season in the Big Apple. The 74-foot Norway spruce was driven into Manhattan's Center Plaza, where it was hoisted in...

In a touching display of compassion and solidarity, a group of St Thomas residents has come together to organise the funeral of a a well-known and beloved man with intellectual challenges. For years, Donovan Sinclair was a familiar face in the...

Broad-specificity glycoside hydrolases (GHs) contribute to plant biomass hydrolysis by degrading a diverse range of polysaccharides, making them useful catalysts for renewable energy and biocommodity production. Discovery of new GHs with improved kinetic parameters or more tolerant substrate-binding sites could increase the efficiency of renewable bioenergy production even further. GH5 has over 50 subfamilies exhibiting selectivities for reaction with β-(1,4)–linked oligo- and polysaccharides. Among these, subfamily 4 (GH5_4) contains numerous broad-selectivity endoglucanases that hydrolyze cellulose, xyloglucan, and mixed-linkage glucans. We previously surveyed the whole subfamily and found over 100 new broad-specificity endoglucanases, although the structural origins of broad specificity remained unclear. A mechanistic understanding of GH5_4 substrate specificity would help inform the best protein design strategies and the most appropriate industrial application of broad-specificity endoglucanases. Here we report structures of 10 new GH5_4 enzymes from cellulolytic microbes and characterize their substrate selectivity using normalized reducing sugar assays and MS. We found that GH5_4 enzymes have the highest catalytic efficiency for hydrolysis of xyloglucan, glucomannan, and soluble β-glucans, with opportunistic secondary reactions on cellulose, mannan, and xylan. The positions of key aromatic residues determine the overall reaction rate and breadth of substrate tolerance, and they contribute to differences in oligosaccharide cleavage patterns. Our new composite model identifies several critical structural features that confer broad specificity and may be readily engineered into existing industrial enzymes. We demonstrate that GH5_4 endoglucanases can have broad specificity without sacrificing high activity, making them a valuable addition to the biomass deconstruction toolset.

Visual Abstract

Yadong Yu
Dec 1, 2020; 19:1997-2014
Research

Ji Eun Kim
Dec 20, 2020; 0:RA120.002159v1-mcp.RA120.002159
Research

Alison M. Kurimchak
Dec 1, 2020; 19:2068-2089
Research

Peter Lasch
Dec 1, 2020; 19:2125-2138
Technological Innovation and Resources

Colin T. McDowell
Nov 24, 2020; 0:RA120.002256v1-mcp.RA120.002256
Research

Congcong Lu
Nov 17, 2020; 0:R120.002257v1-mcp.R120.002257
Review

Tuberculosis (TB), caused by the infection of Mycobacterium tuberculosis (MTB), is one of the leading causes of death worldwide, especially in children. However, the mechanisms by which MTB infects its cellular host, activates an immune response, and triggers inflammation remain unknown. Mitochondria play important roles in the initiation and activation of the nucleotide-binding oligomerization domain-like receptor with a pyrin domain 3 (NLRP3) inflammasome, where mitochondria-associated endoplasmic reticulum membranes (MAMs) may serve as the platform for inflammasome assembly and activation. Additionally, mitofusin 2 (MFN2) is implicated in the formation of MAMs, but, the roles of mitochondria and MFN2 in MTB infection have not been elucidated. Using mircroarry profiling of TB patients and in vitro MTB stimulation of macrophages, we observed an up-regulation of MFN2 in the peripheral blood mononuclear cells of active TB patients. Furthermore, we found that MTB stimulation by MTB-specific antigen ESAT-6 or lysate of MTB promoted MFN2 interaction with NLRP3 inflammasomes, resulting in the assembly and activation of the inflammasome and, subsequently, IL-1β secretion. These findings suggest that MFN2 and mitochondria play important role in the pathogen-host interaction during MTB infection.

Douglas A. Andres
Dec 1, 2020; 61:1537-1537
Images in Lipid Research

Astrid M. Moerman
Dec 23, 2020; 0:jlr.RA120000974v1-jlr.RA120000974
Research Articles

Amyloid fibrils are polymeric structures originating from aggregation of misfolded proteins. In vivo, proteolysis may modulate amyloidogenesis and fibril stability. In light chain (AL) amyloidosis, fragmented light chains (LCs) are abundant components of amyloid deposits; however, site and timing of proteolysis are debated. Identification of the N and C termini of LC fragments is instrumental to understanding involved processes and enzymes. We investigated the N and C terminome of the LC proteoforms in fibrils extracted from the hearts of two AL cardiomyopathy patients, using a proteomic approach based on derivatization of N- and C-terminal residues, followed by mapping of fragmentation sites on the structures of native and fibrillar relevant LCs. We provide the first high-specificity map of proteolytic cleavages in natural AL amyloid. Proteolysis occurs both on the LC variable and constant domains, generating a complex fragmentation pattern. The structural analysis indicates extensive remodeling by multiple proteases, largely taking place on poorly folded regions of the fibril surfaces. This study adds novel important knowledge on amyloid LC processing: although our data do not exclude that proteolysis of native LC dimers may destabilize their structure and favor fibril formation, the data show that LC deposition largely precedes the proteolytic events documentable in mature AL fibrils.

Carotid atherosclerosis is a risk factor for ischemic stroke, one of the main causes of mortality and disability worldwide. The disease is characterized by plaques, heterogeneous deposits of lipids and necrotic debris in the vascular wall, which grow gradually and may remain asymptomatic for decades. However, at some point a plaque can evolve to a high-risk plaque phenotype, which may trigger a cerebrovascular event. Lipids play a key role in the development and progression of atherosclerosis, but the nature of their involvement is not fully understood. Using matrix-assisted laser desorption/ionization mass spectrometry imaging, we visualized the distribution of approximately 200 different lipid signals, originating of > 90 uniquely assigned species, in 106 tissue sections of 12 human carotid atherosclerotic plaques. We performed unsupervised classification of the mass spectrometry dataset, as well as a histology-directed multivariate analysis. These data allowed us to extract the spatial lipid patterns associated with morphological plaque features in advanced plaques from a symptomatic population, revealing spatial lipid patterns in atherosclerosis and their relation to histological tissue type. The abundances of sphingomyelin and oxidized cholesteryl ester species were elevated specifically in necrotic intima areas, while diacylglycerols and triacylglycerols were spatially correlated to areas containing the coagulation protein fibrin. These results demonstrate a clear co-localization between plaque features and specific lipid classes, as well as individual lipid species in high-risk atherosclerotic plaques.

Recent efforts in gut microbiome studies have highlighted the importance of explicitly describing the ecological processes beyond correlative analysis. However, we are still at the early stage of understanding the organizational principles of the gut ecosystem, partially because of the limited information provided by currently used analytical tools in ecological modeling practices. Proteomics and metaproteomics can provide a number of insights for ecological studies, including biomass, matter and energy flow, and functional diversity. In this Mini Review, we discuss proteomics and metaproteomics-based experimental strategies that can contribute to studying the ecology, in particular at the mucosal-luminal interface (MLI) where the direct host-microbiome interaction happens. These strategies include isolation protocols for different MLI components, enrichment methods to obtain designated array of proteins, probing for specific pathways, and isotopic labeling for tracking nutrient flow. Integration of these technologies can generate spatiotemporal and site-specific biological information that supports mathematical modeling of the ecosystem at the MLI.