degradation

Advanced oxidative degradation of monoethanolamine in water using ultraviolet light and hydrogen peroxide

RSC Adv., 2024, 14,33223-33232
DOI: 10.1039/D4RA05590J, Paper
Open Access
  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Atif Khan, Saima Yasin, Hamayoun Mahmood, Shabana Afzal, Tanveer Iqbal
Development of an eco-friendly and commercially feasible method for monoethanolamine (MEA) degradation in aqueous phase using ultraviolet/hydrogen peroxide (UV/H2O2) advanced oxidation process (AOP).
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Porous CaMnO3-promoted g-C3N4 as an effective photocatalyst for tetracycline degradation

RSC Adv., 2024, 14,36181-36192
DOI: 10.1039/D4RA06407K, Paper
Open Access
Bo Zhang, Chaoqi Li, Shasha Liu, Lixuan Zhuang, Weiqi Zhang, Limei Huang, Zhenzhen Jia, Dongdong Chen, Xiang Li
Non-expensive CaMnO3 perovskite oxide can assist in developing efficient g-C3N4-based photocatalysts aimed at removing antibiotics from wastewater.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

DOM removal from Lake Kinneret by adsorption columns and biodegradation: a pilot study and modeling

Environ. Sci.: Water Res. Technol., 2024, 10,2736-2751
DOI: 10.1039/D4EW00407H, Paper
Mario L. Kummel, Ofri B. Zusman, Shlomo Nir, Yael G. Mishael
A study on the removal of DOM from Lake Kinneret, the main surface drinking water source in Israel, was conducted applying an adsorption pilot plant with columns that included granular activated carbons, a clay–polymer nanocomposite and a combination of both.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Synergistic effect of the heterojunction g-C3N4/Bi2MoO6/clinoptilolite to enhance the photocatalytic degradation of antibiotics in water in the presence of persulfate

Environ. Sci.: Water Res. Technol., 2024, 10,2665-2687
DOI: 10.1039/D4EW00549J, Paper
Phuong Thu Le, Thu Phuong Nguyen, Thi Hai Do, Hong Nam Nguyen, Thi Mai Thanh Dinh, Thi Thuy Phan, Toshiki Tsubota, Trung Dung Nguyen
Proposed mechanism of OTC photocatalytic degradation by the CNBC-30/PDS/Vis system.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Degradation of benzylamines during chlorination and chloramination

Environ. Sci.: Water Res. Technol., 2024, 10,2655-2664
DOI: 10.1039/D4EW00556B, Paper
Chih-Hsien Lin, Wei-Hsiang Chen, William A. Mitch
This study characterized the degradation pathways of benzylamine, N-methylbenzylamine and N,N-dimethylbenzylamine during chlorination and chloramination.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Fe3+ and H2O2 assisted dopamine rapid polymerization on melamine foam to activate PMS for organic pollutant degradation

Environ. Sci.: Water Res. Technol., 2024, 10,2698-2708
DOI: 10.1039/D4EW00596A, Paper
Haoxiang Yan, Jianzheng Zhen, Yuyuan Yao
A bulk sponge catalytic material was prepared by rapid polymerization of DA and utilized for PMS activation to degrade BPA. The coexistence of HCO3 enhanced 1O2 generation, accelerating BPA degradation.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Microwave irradiation synthesis of CoFe2O4/rGO to activate peroxymonosulfate for the degradation of 2-aminobenzothiazole in water

Environ. Sci.: Water Res. Technol., 2024, 10,2946-2960
DOI: 10.1039/D4EW00459K, Paper
Wei Wei, Shiqian Gao, Feiyue Qian, Chongjun Chen, Youyi Wu
CoFe2O4/rGO MNPs synthesized via an in situ microwave irradiation method were used as a heterogeneous catalyst to activate PMS for the degradation of ABT. Its mechanism was explored, and the catalytic system was applied to real water samples.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Sorption and biodegradation of stormwater trace organic contaminants via composite alginate bead geomedia with encapsulated microorganisms

Environ. Sci.: Water Res. Technol., 2024, Advance Article
DOI: 10.1039/D4EW00600C, Paper
Open Access
  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Debojit S. Tanmoy, Gregory H. LeFevre
We quantified sorption of stormwater relevant trace organic contaminants and dissolved phosphorus to a novel composite-alginate geomedia. We demonstrated coupled sorption and biodegradation of a representative tirewear compound via the geomedia.
To cite this article before page numbers are assigned, use the DOI form of citation above.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Revealing degradation mechanisms in 3D/2D perovskite solar cells under photothermal accelerated ageing

Energy Environ. Sci., 2024, 17,8313-8324
DOI: 10.1039/D4EE03869J, Paper
Open Access
  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Zijian Peng, Andrej Vincze, Fabian Streller, Vincent M. Le Corre, Kaicheng Zhang, Chaohui Li, Jingjing Tian, Chao Liu, Junsheng Luo, Yicheng Zhao, Andreas Späth, Rainer Fink, Thomas Heumüller, Andres Osvet, Ning Li, Martin Stolterfoht, Larry Lüer, Christoph J. Brabec
Three-dimensional/two-dimensional (3D/2D) heterojunctions in perovskite solar cells exhibit excellent optoelectronic properties and enhanced stability under mild ageing conditions.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Decoupling light- and oxygen-induced degradation mechanisms of Sn–Pb perovskites in all perovskite tandem solar cells

Energy Environ. Sci., 2024, 17,8557-8569
DOI: 10.1039/D4EE02427C, Paper
Open Access
Yang Bai, Ruijia Tian, Kexuan Sun, Chang Liu, Xiting Lang, Ming Yang, Yuanyuan Meng, Chuanxiao Xiao, Yaohua Wang, Xiaoyi Lu, Jingnan Wang, Haibin Pan, Zhenhua Song, Shujing Zhou, Ziyi Ge
This study showed PEHCl-CN can enhance the strength of Sn–I, resulting in good light stability. The subsequent doping of MBI resulted in good air stability. This enables the integrated 2T all-perovskite device to achieve an efficiency of 27.9%.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Machine-learning assisted optimisation during heterogeneous photocatalytic degradation utilising a static mixer under continuous flow

React. Chem. Eng., 2024, 9,872-882
DOI: 10.1039/D3RE00570D, Paper
Open Access
  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Thomas M. Kohl, Yan Zuo, Benjamin W. Muir, Christian H. Hornung, Anastasios Polyzos, Yutong Zhu, Xingdong Wang, David L. J. Alexander
Machine-learning assisted optimisation of a continuous photodegradation reaction, using a TiO2 coated catalytic static mixer successfully accounting for catalyst degradation.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Catalytic degradation of pine sawdust over heterotopic Ca–Fe and HZSM-5 to produce aromatic hydrocarbons

React. Chem. Eng., 2024, Advance Article
DOI: 10.1039/D3RE00572K, Paper
Huifen Kang, Xintong Guo, Mei An, Conghua Ma, Guozhang Chang, Qingjie Guo, Jingjing Ma
Up to 90.47% aromatic proportion and a 31.02 mg g−1 BTEX yield were obtained by heterogeneous catalysis of Ca–Fe and HZSM-5.
To cite this article before page numbers are assigned, use the DOI form of citation above.
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Unraveling the Ammonia Sensing Behavior and Degradation Pathways of Novel Lead-Free MA2CuBr4 based Ammonia Sensor

Nanoscale, 2024, Accepted Manuscript
DOI: 10.1039/D4NR02943G, Communication
Abinash Tiwari, Arjumand Mir, Aswani Yella
We report a lead-free copper-based halide perovskite gas sensor to detect ammonia gas at ambient temperature. The sensor uses methylammonium copper bromide as the active material and can trace ammonia...
The content of this RSS Feed (c) The Royal Society of Chemistry




degradation

Catabolic degradation of endothelial VEGFA via autophagy [Glycobiology and Extracellular Matrices]

Extracellular matrix-evoked angiostasis and autophagy within the tumor microenvironment represent two critical, but unconnected, functions of the small leucine-rich proteoglycan, decorin. Acting as a partial agonist of vascular endothelial growth factor 2 (VEGFR2), soluble decorin signals via the energy sensing protein, AMP-activated protein kinase (AMPK), in the autophagic degradation of intracellular vascular endothelial growth factor A (VEGFA). Here, we discovered that soluble decorin evokes intracellular catabolism of endothelial VEGFA that is mechanistically independent of mTOR, but requires an autophagic regulator, paternally expressed gene 3 (PEG3). We found that administration of autophagic inhibitors such as chloroquine or bafilomycin A1, or depletion of autophagy-related 5 (ATG5), results in accumulation of intracellular VEGFA, indicating that VEGFA is a basal autophagic substrate. Mechanistically, decorin increased the VEGFA clearance rate by augmenting autophagic flux, a process that required RAB24 member RAS oncogene family (RAB24), a small GTPase that facilitates the disposal of autophagic compartments. We validated these findings by demonstrating the physiological relevance of this process in vivo. Mice starved for 48 h exhibited a sharp decrease in overall cardiac and aortic VEGFA that could be blocked by systemic chloroquine treatment. Thus, our findings reveal a unified mechanism for the metabolic control of endothelial VEGFA for autophagic clearance in response to decorin and canonical pro-autophagic stimuli. We posit that the VEGFR2/AMPK/PEG3 axis integrates the anti-angiogenic and pro-autophagic bioactivities of decorin as the molecular basis for tumorigenic suppression. These results support future therapeutic use of decorin as a next-generation protein therapy to combat cancer.




degradation

Smithsonian to lead study on degradation of nearshore coastal habitats of the Chesapeake

Invasive species, contaminants, excessive nutrient's and sediment are just some of the many factors threatening sensitive wetlands and seagrass beds.

The post Smithsonian to lead study on degradation of nearshore coastal habitats of the Chesapeake appeared first on Smithsonian Insider.




degradation

Soil degradation: the impact of rainfall on soil condition

The status of soil can be represented by many properties. However, how well they represent soil status depends on the level of rainfall in the area. Researchers in Spain found that in wet regions soil status is strongly linked to biological factors, such as vegetation cover and biodiversity. In drier regions, status has a stronger link to the physical properties of the soil.




degradation

Mediterranean land degradation threatens food security

Climate change, tourism and population growth are all accelerating land degradation in the Mediterranean region, according to recent research. This can have severe impacts: the amount of available agricultural land per capita in the region could have dropped by half by 2020, compared with 1961, the study estimates. This article was updated 6.11.14 to correct an error in the valuation of ecosystem services provided by Mediterranean coastal wetlands.




degradation

Understanding degradation of battery life-time is key to successful vehicle-to-grid systems

Electric vehicles (EVs) could play a role in future power supply, but face issues surrounding the longevity of their batteries. This study reconciles two recent contradictory results on the effects of vehicle-to-grid (V2G) technology on battery life-time, and shows that V2G — a process via which EVs would exchange energy with the power grid to provide ancillary services, such as supplying power during peak periods, and helping to regulate grid frequency — could actually extend the lifespan of commercial lithium-ion batteries.




degradation

Causes of ecological degradation in waterways

Human activities can have a multitude of different effects on rivers and streams, and it is difficult identify those that have the biggest impact on aquatic populations. A newly developed method for assessing ecological degradation in waterways helps deal with this problem and could provide crucial information for water managers charged with tackling the root causes of degradation.




degradation

Biodegradation of PPCPs in wastewater treatment plants — a Danish case study

The non-restricted production and use of pharmaceuticals and personal care products (PPCPs) has led to their presence in effluents from treatment plants, which can pose a threat to aquatic organisms downstream. This study analysed the breakdown of six common chemicals in four Danish treatment plants. The findings shed new light on the factors affecting removal of PPCPs from waste, showing that the composition of waste is more important than the design of the treatment plant.




degradation

Multi-pollutant approach needed to halt soil degradation

A new study highlights the need for new policies to stop the rise of nitrogen oxide emissions in China. The researchers suggest that the positive impact of policies to reduce sulphur dioxide emissions are not enough in themselves to avoid soil acidification, as they will be outweighed over the next decade by the impact of nitrogen emissions.




degradation

25% of all deaths linked to pollution and environmental degradation

1 in 4 global deaths can be attributed to an unhealthy environment. Who says environmentalism is for the birds?



  • Fitness & Well-Being

degradation

Method for the degradation of pollutants in water and/or soil

The present invention relates to a method for the degradation of pollutants in water and/or soil. More specific, the present invention relates to a method for the on-site decontamination or re-mediation of water and/or soil which are contaminated with organic compounds. Moreover, the invention relates to a method for forming a barrier against the spreading of a contamination with pollutants within the water and/or soil, especially within groundwater (aquifer). Further, the invention relates to means for use in these methods, and to the production of such means.




degradation

Degradation of phosphate esters by high oxidation state molybdenum complexes

Degradation of phosphate esters, particularly neurotoxins and pesticides, is performed using high oxidative state molybdenum complexes, more particularly molybdenum(VI) complexes. A molybdenum(VI) complex is dissolved in water and then reacted with a phosphate ester. The phosphate esters can include, but are not limited to, VX, VE, VG, VM, GB, GD, GA, GF, parathion, paraoxon, triazophos, oxydemeton-methyl, chlorpyrifos, fenitrothion and pirimiphos-methyl, representing both chemical warfare agents as well as pesticides and insecticides.




degradation

Battery degradation determination device, battery degradation determination method and battery degradation determination system

A battery degradation determination device includes a fitting module configured to fit AC impedance measurement data into an equivalent circuit model including at least one circuit block in which a resistance and a constant phase element are connected in parallel, and to obtain circuit constants in the equivalent circuit model, a P-value saving module configured to save P values being index of the constant phase element obtained by fitting AC impedance measurement data of a reference battery to the equivalent circuit model, and a degradation determination module configured to perform degradation determination for a battery as a determination target based on circuit constants obtained by fitting AC impedance measurement data of the battery as a determination target to the equivalent circuit model with the use of the P values as fixed values, with reference to correlations between degrees of battery degradation and the circuit constants in the equivalent circuit model.




degradation

System and method for compensating signal degradation in dual polarization optical systems

A method for adjusting an optical signal includes determining a polarization dependent loss (PDL) value associated with the optical signal, determining an angle between the optical signal and one or more axes of PDL, determining an amount of nonlinear phase noise due to PDL and nonlinear effects upon the optical signal based upon the PDL value and the angle, determining a phase rotation based upon the amount of nonlinear phase noise, and applying the phase rotation to the optical signal.




degradation

Hydrogel tissue adhesive having decreased gelation time and decreased degradation time

A hydrogel tissue adhesive having decreased gelation time and decreased degradation time is described. The hydrogel tissue adhesive is formed by reacting an oxidized polysaccharide containing aldehyde groups with a water-dispersible, multi-arm amine in the presence of a thiol additive. The thiol additive accelerates the process to form the hydrogel and accelerates the degradation of the hydrogel formed. The hydrogel may be useful as a tissue adhesive or sealant for medical applications, such as a hemostat sealant or to prevent undesired tissue-to-tissue adhesions resulting from trauma or surgery.




degradation

Compositions promoting the accelerated degradation of metals and composite materials

A composition to decommission firearms is presented. The composition comprises a monomer, a quantity of calcium chloride; and sulfur-containing compound. The sulfur containing compound includes sodium persulfate and/or sodium thiosulfate.




degradation

Degradation of TATP, TNT and RDX using mechanically alloyed metals

Bimetallic alloys prepared in a ball milling process, such as iron nickel (FeNi), iron palladium (FePd), and magnesium palladium (MgPd) provide in situ catalyst system for remediating and degrading nitro explosive compounds. Specifically, munitions, such as, 2,4,6-trinitrotoluene (TNT), cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX), nitrocellulose and nitroglycerine that have become contaminants in groundwater, soil, and other structures are treated on site to remediate explosive contamination.




degradation

METHOD AND DEVICE FOR SEPARATING CARBON DIOXIDE FROM A GAS STREAM AND FOR REMOVING DEGRADATION PRODUCTS IN THE WASHING MEDIUM BY PHOTOLYTIC DECOMPOSITION

A method for separating carbon dioxide from a gas stream, in particular from a flue gas stream, wherein, a gas stream is brought into contact with a washing medium in an absorber of a separation device and the carbon dioxide contained in the gas stream is separated; the charged washing medium is supplied to a desorber of the separation device to release the carbon dioxide; a vapor stream is removed from the desorber and is supplied to a cooling unit to form a condensate; degradation products, in particular nitrosamines, contained in at least a partial stream of the condensate are photolytically decomposed to decomposition products; at least the decomposition products, in particular nitrites and amines, are removed; and at least a partial stream of the condensate is returned to the desorber. A corresponding separation device separates carbon dioxide from a gas stream.




degradation

Technologies for controlling degradation of sensing circuits

Technologies for controlling degradation of a sensor mote including detecting a trigger event and initiating degradation of at least a portion of the sensor mote in response to the trigger event. The trigger event may be embodied as any type of event detectable by the sensor mote such as a trigger signal, particular sensed data, expiration of a reference time period, completion of a task, and so forth. The sensor mote may imitate the degradation by, for example, controlling a valve to release a chemical stored in the sensor mote or allow a substance into the sensor mote.




degradation

COPPER NANOPARTICLES FOR DEGRADATION OF POLLUTANTS

The present invention is directed to a degradation composition, methods and kits for degrading organic pollutants comprising reduced copper based nanoparticles-polymer complex (Cu-NPs) and an oxidant.




degradation

The hibernating 100S complex is a target of ribosome-recycling factor and elongation factor G in Staphylococcus aureus [Protein Synthesis and Degradation]

The formation of translationally inactive 70S dimers (called 100S ribosomes) by hibernation-promoting factor is a widespread survival strategy among bacteria. Ribosome dimerization is thought to be reversible, with the dissociation of the 100S complexes enabling ribosome recycling for participation in new rounds of translation. The precise pathway of 100S ribosome recycling has been unclear. We previously found that the heat-shock GTPase HflX in the human pathogen Staphylococcus aureus is a minor disassembly factor. Cells lacking hflX do not accumulate 100S ribosomes unless they are subjected to heat exposure, suggesting the existence of an alternative pathway during nonstressed conditions. Here, we provide biochemical and genetic evidence that two essential translation factors, ribosome-recycling factor (RRF) and GTPase elongation factor G (EF-G), synergistically split 100S ribosomes in a GTP-dependent but tRNA translocation-independent manner. We found that although HflX and the RRF/EF-G pair are functionally interchangeable, HflX is expressed at low levels and is dispensable under normal growth conditions. The bacterial RRF/EF-G pair was previously known to target only the post-termination 70S complexes; our results reveal a new role in the reversal of ribosome hibernation that is intimately linked to bacterial pathogenesis, persister formation, stress responses, and ribosome integrity.




degradation

The hibernating 100S complex is a target of ribosome-recycling factor and elongation factor G in Staphylococcus aureus [Protein Synthesis and Degradation]

The formation of translationally inactive 70S dimers (called 100S ribosomes) by hibernation-promoting factor is a widespread survival strategy among bacteria. Ribosome dimerization is thought to be reversible, with the dissociation of the 100S complexes enabling ribosome recycling for participation in new rounds of translation. The precise pathway of 100S ribosome recycling has been unclear. We previously found that the heat-shock GTPase HflX in the human pathogen Staphylococcus aureus is a minor disassembly factor. Cells lacking hflX do not accumulate 100S ribosomes unless they are subjected to heat exposure, suggesting the existence of an alternative pathway during nonstressed conditions. Here, we provide biochemical and genetic evidence that two essential translation factors, ribosome-recycling factor (RRF) and GTPase elongation factor G (EF-G), synergistically split 100S ribosomes in a GTP-dependent but tRNA translocation-independent manner. We found that although HflX and the RRF/EF-G pair are functionally interchangeable, HflX is expressed at low levels and is dispensable under normal growth conditions. The bacterial RRF/EF-G pair was previously known to target only the post-termination 70S complexes; our results reveal a new role in the reversal of ribosome hibernation that is intimately linked to bacterial pathogenesis, persister formation, stress responses, and ribosome integrity.




degradation

SUMOylation of the transcription factor ZFHX3 at Lys-2806 requires SAE1, UBC9, and PIAS2 and enhances its stability and function in cell proliferation [Protein Synthesis and Degradation]

SUMOylation is a posttranslational modification (PTM) at a lysine residue and is crucial for the proper functions of many proteins, particularly of transcription factors, in various biological processes. Zinc finger homeobox 3 (ZFHX3), also known as AT motif-binding factor 1 (ATBF1), is a large transcription factor that is active in multiple pathological processes, including atrial fibrillation and carcinogenesis, and in circadian regulation and development. We have previously demonstrated that ZFHX3 is SUMOylated at three or more lysine residues. Here, we investigated which enzymes regulate ZFHX3 SUMOylation and whether SUMOylation modulates ZFHX3 stability and function. We found that SUMO1, SUMO2, and SUMO3 each are conjugated to ZFHX3. Multiple lysine residues in ZFHX3 were SUMOylated, but Lys-2806 was the major SUMOylation site, and we also found that it is highly conserved among ZFHX3 orthologs from different animal species. Using molecular analyses, we identified the enzymes that mediate ZFHX3 SUMOylation; these included SUMO1-activating enzyme subunit 1 (SAE1), an E1-activating enzyme; SUMO-conjugating enzyme UBC9 (UBC9), an E2-conjugating enzyme; and protein inhibitor of activated STAT2 (PIAS2), an E3 ligase. Multiple analyses established that both SUMO-specific peptidase 1 (SENP1) and SENP2 deSUMOylate ZFHX3. SUMOylation at Lys-2806 enhanced ZFHX3 stability by interfering with its ubiquitination and proteasomal degradation. Functionally, Lys-2806 SUMOylation enabled ZFHX3-mediated cell proliferation and xenograft tumor growth of the MDA-MB-231 breast cancer cell line. These findings reveal the enzymes involved in, and the functional consequences of, ZFHX3 SUMOylation, insights that may help shed light on ZFHX3's roles in various cellular and pathophysiological processes.




degradation

The heme-regulatory motifs of heme oxygenase-2 contribute to the transfer of heme to the catalytic site for degradation [Protein Structure and Folding]

Heme-regulatory motifs (HRMs) are present in many proteins that are involved in diverse biological functions. The C-terminal tail region of human heme oxygenase-2 (HO2) contains two HRMs whose cysteine residues form a disulfide bond; when reduced, these cysteines are available to bind Fe3+-heme. Heme binding to the HRMs occurs independently of the HO2 catalytic active site in the core of the protein, where heme binds with high affinity and is degraded to biliverdin. Here, we describe the reversible, protein-mediated transfer of heme between the HRMs and the HO2 core. Using hydrogen-deuterium exchange (HDX)-MS to monitor the dynamics of HO2 with and without Fe3+-heme bound to the HRMs and to the core, we detected conformational changes in the catalytic core only in one state of the catalytic cycle—when Fe3+-heme is bound to the HRMs and the core is in the apo state. These conformational changes were consistent with transfer of heme between binding sites. Indeed, we observed that HRM-bound Fe3+-heme is transferred to the apo-core either upon independent expression of the core and of a construct spanning the HRM-containing tail or after a single turnover of heme at the core. Moreover, we observed transfer of heme from the core to the HRMs and equilibration of heme between the core and HRMs. We therefore propose an Fe3+-heme transfer model in which HRM-bound heme is readily transferred to the catalytic site for degradation to facilitate turnover but can also equilibrate between the sites to maintain heme homeostasis.




degradation

Schnyder corneal dystrophy-associated UBIAD1 is defective in MK-4 synthesis and resists autophagy-mediated degradation [Research Articles]

The autosomal dominant disorder Schnyder corneal dystrophy (SCD) is caused by mutations in UbiA prenyltransferase domain-containing protein-1 (UBIAD1), which uses geranylgeranyl pyrophosphate (GGpp) to synthesize the vitamin K2 subtype menaquinone-4 (MK-4). SCD is characterized by opacification of the cornea, owing to aberrant build-up of cholesterol in the tissue. We previously discovered that sterols stimulate association of UBIAD1 with ER-localized HMG-CoA reductase, which catalyzes a rate-limiting step in the synthesis of cholesterol and nonsterol isoprenoids, including GGpp. Binding to UBIAD1 inhibits sterol-accelerated ER-associated degradation (ERAD) of reductase and permits continued synthesis of GGpp in cholesterol-replete cells. GGpp disrupts UBIAD1-reductase binding and thereby allows for maximal ERAD of reductase as well as ER-to-Golgi translocation of UBIAD1. SCD-associated UBIAD1 is refractory to GGpp-mediated dissociation from reductase and remains sequestered in the ER to inhibit ERAD. Here, we report development of a biochemical assay for UBIAD1-mediated synthesis of MK-4 in isolated membranes and intact cells. Using this assay, we compared enzymatic activity of WT UBIAD1 with that of SCD-associated variants. Our studies revealed that SCD-associated UBIAD1 exhibited reduced MK-4 synthetic activity, which may result from its reduced affinity for GGpp. Sequestration in the ER protects SCD-associated UBIAD1 from autophagy and allows intracellular accumulation of the mutant protein, which amplifies the inhibitory effect on reductase ERAD. These findings have important implications not only for the understanding of SCD etiology but also for the efficacy of cholesterol-lowering statin therapy, which becomes limited, in part, because of UBIAD1-mediated inhibition of reductase ERAD.




degradation

CBD News: Message from Mr. Ahmed djoghlaf, Executive Secretary, on the occasion of the World Day to Combat Desertification: Combating Land Degradation for Sustainable Agriculture.




degradation

CBD News: The CBD Secretariat is launching an e-Newsletter on "Reducing Emissions from Deforestation and Forest Degradation (REDD)" today, to inform CBD National Focal Points and other interested recipients about the biodiversity aspects of this




degradation

CBD News: CBD provides free tool to identify win-win areas for REDD and biodiversity. The Bali Action plan under the United Nations FCCC encourages efforts to reduce emissions from reducing emissions from deforestation and forest degradation (REDD), while




degradation

CBD Press Release: Climate change, biodiversity loss, deforestation and land degradation addressed as a single challenge at the Aichi Nagoya Biodiversity Summit.




degradation

CBD News: As governments meet in the Republic of Korea to address the challenges of land degradation under the United Nations Convention to Combat Desertification, global actors will meet at the Rio Conventions Pavilion to communicate their coordinated




degradation

CBD News: US$ 4.43 billion has been pledged by 30 donor countries for the Global Environment Facility (GEF) to support developing countries' efforts over the next four years to prevent degradation of the global environment.




degradation

CBD News: The Secretariat of the Convention on Biological Diversity welcomes Pope Francis' call to action in the face of global biodiversity loss, climate change and environmental degradation.




degradation

CBD News: Though there have been rapid advances in human health, the continuing degradation of our planetary systems does not bode well for its future. Today, The Rockefeller Foundation-Lancet Commission on Planetary Health launched a comprehensive report




degradation

CBD News: Statement by Ms. Cristiana Pa?ca Palmer, Executive Secretary of the Convention on Biological Diversity, on the occasion of the African Ministerial Summit on Biodiversity: "Land and ecosystem degradation and restoration: Priorities for incre




degradation

CBD News: African Ministers of Environment together with partner organizations committed to an ambitious action agenda taking a coherent approach to addressing the interlinked challenges of biodiversity loss, land degradation and climate change.




degradation

The heme-regulatory motifs of heme oxygenase-2 contribute to the transfer of heme to the catalytic site for degradation [Protein Structure and Folding]

Heme-regulatory motifs (HRMs) are present in many proteins that are involved in diverse biological functions. The C-terminal tail region of human heme oxygenase-2 (HO2) contains two HRMs whose cysteine residues form a disulfide bond; when reduced, these cysteines are available to bind Fe3+-heme. Heme binding to the HRMs occurs independently of the HO2 catalytic active site in the core of the protein, where heme binds with high affinity and is degraded to biliverdin. Here, we describe the reversible, protein-mediated transfer of heme between the HRMs and the HO2 core. Using hydrogen-deuterium exchange (HDX)-MS to monitor the dynamics of HO2 with and without Fe3+-heme bound to the HRMs and to the core, we detected conformational changes in the catalytic core only in one state of the catalytic cycle—when Fe3+-heme is bound to the HRMs and the core is in the apo state. These conformational changes were consistent with transfer of heme between binding sites. Indeed, we observed that HRM-bound Fe3+-heme is transferred to the apo-core either upon independent expression of the core and of a construct spanning the HRM-containing tail or after a single turnover of heme at the core. Moreover, we observed transfer of heme from the core to the HRMs and equilibration of heme between the core and HRMs. We therefore propose an Fe3+-heme transfer model in which HRM-bound heme is readily transferred to the catalytic site for degradation to facilitate turnover but can also equilibrate between the sites to maintain heme homeostasis.




degradation

Catabolic degradation of endothelial VEGFA via autophagy [Glycobiology and Extracellular Matrices]

Extracellular matrix-evoked angiostasis and autophagy within the tumor microenvironment represent two critical, but unconnected, functions of the small leucine-rich proteoglycan, decorin. Acting as a partial agonist of vascular endothelial growth factor 2 (VEGFR2), soluble decorin signals via the energy sensing protein, AMP-activated protein kinase (AMPK), in the autophagic degradation of intracellular vascular endothelial growth factor A (VEGFA). Here, we discovered that soluble decorin evokes intracellular catabolism of endothelial VEGFA that is mechanistically independent of mTOR, but requires an autophagic regulator, paternally expressed gene 3 (PEG3). We found that administration of autophagic inhibitors such as chloroquine or bafilomycin A1, or depletion of autophagy-related 5 (ATG5), results in accumulation of intracellular VEGFA, indicating that VEGFA is a basal autophagic substrate. Mechanistically, decorin increased the VEGFA clearance rate by augmenting autophagic flux, a process that required RAB24 member RAS oncogene family (RAB24), a small GTPase that facilitates the disposal of autophagic compartments. We validated these findings by demonstrating the physiological relevance of this process in vivo. Mice starved for 48 h exhibited a sharp decrease in overall cardiac and aortic VEGFA that could be blocked by systemic chloroquine treatment. Thus, our findings reveal a unified mechanism for the metabolic control of endothelial VEGFA for autophagic clearance in response to decorin and canonical pro-autophagic stimuli. We posit that the VEGFR2/AMPK/PEG3 axis integrates the anti-angiogenic and pro-autophagic bioactivities of decorin as the molecular basis for tumorigenic suppression. These results support future therapeutic use of decorin as a next-generation protein therapy to combat cancer.




degradation

The hibernating 100S complex is a target of ribosome-recycling factor and elongation factor G in Staphylococcus aureus [Protein Synthesis and Degradation]

The formation of translationally inactive 70S dimers (called 100S ribosomes) by hibernation-promoting factor is a widespread survival strategy among bacteria. Ribosome dimerization is thought to be reversible, with the dissociation of the 100S complexes enabling ribosome recycling for participation in new rounds of translation. The precise pathway of 100S ribosome recycling has been unclear. We previously found that the heat-shock GTPase HflX in the human pathogen Staphylococcus aureus is a minor disassembly factor. Cells lacking hflX do not accumulate 100S ribosomes unless they are subjected to heat exposure, suggesting the existence of an alternative pathway during nonstressed conditions. Here, we provide biochemical and genetic evidence that two essential translation factors, ribosome-recycling factor (RRF) and GTPase elongation factor G (EF-G), synergistically split 100S ribosomes in a GTP-dependent but tRNA translocation-independent manner. We found that although HflX and the RRF/EF-G pair are functionally interchangeable, HflX is expressed at low levels and is dispensable under normal growth conditions. The bacterial RRF/EF-G pair was previously known to target only the post-termination 70S complexes; our results reveal a new role in the reversal of ribosome hibernation that is intimately linked to bacterial pathogenesis, persister formation, stress responses, and ribosome integrity.