Biochimica et biophysica acta. Proteins and proteomics最新文献

{"title":"A distinct co-expressed sulfurtransferase extends the physiological role of mercaptopropionate dioxygenase in Pseudomonas aeruginosa PAO1","authors":"Chukwuemeka S. Adindu ,&nbsp;Katie Tombrello ,&nbsp;Luke A. Martz ,&nbsp;Tonya N. Zeczycki ,&nbsp;Holly R. Ellis","doi":"10.1016/j.bbapap.2024.141059","DOIUrl":"10.1016/j.bbapap.2024.141059","url":null,"abstract":"<div><div>Oxidation and assimilation of persulfides in bacteria is often catalyzed by a persulfide dioxygenase and sulfurtransferase in consecutive reactions. Enzymes responsible for the oxidation of persulfides have not been clearly defined in <em>Pseudomonas aeruginosa</em> PAO1. The characterized mercaptopropionate dioxygenase (MDO) in <em>P. aeruginosa</em> PAO1 has been proposed to catalyze the oxidation of 3-mercaptopropionate. However, the physiological role of MDO is uncertain given the expression of a sulfurtransferase (ST) enzyme on the same operon as the thiol dioxygenase. The <em>st</em> gene had a co-occurrence frequency with <em>mdo</em> of 0.94 demonstrating the co-expression and physiological link of the two genes. There are four tandem rhodanese domains in the ST enzyme with two of the domains containing potential catalytic Cys residues (Cys191 and Cys435) capable of forming a persulfide. Only Cys435 was accessible in thiol quantification assays, and results from H/D-X MS analyses further established the accessibility of the domain containing Cys435. Both thiosulfate and mercaptopyruvate served as sulfur donors to the ST enzyme, with Cys435 forming the persulfide intermediate. Kinetic investigations of MDO suggested the enzyme had a broader substrate specificity than previously identified, oxidizing both mercaptopropionate and mercaptopyruvate thiol and persulfide substrates. The results obtained from these investigations provide insight into the overall mechanism and physiological role of the <em>mdo</em> operon in sulfide oxidation and assimilation.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142543387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the cleavage sites of 3C-like protease in Gammacoronaviruses and Deltacoronaviruses","authors":"Mengxue Wang ,&nbsp;Xinyi Sun ,&nbsp;Shijiang Peng ,&nbsp;Feifan Wang ,&nbsp;Kangli Zhao ,&nbsp;Dang Wang","doi":"10.1016/j.bbapap.2024.141057","DOIUrl":"10.1016/j.bbapap.2024.141057","url":null,"abstract":"<div><div>Coronaviruses replicate by using the 3C-like protease (3CL^pro) to cleave polyprotein precursors and host proteins. However, current tools for identifying 3CL^pro cleavage sites are limited, particularly in <em>Gammacoronaviruses</em> (GammaCoV) and <em>Deltacoronaviruses</em> (DeltaCoV). This study aims to fill this gap by identifying 3CL^pro cleavage sites in these viruses to provide deeper insights into their pathogenic mechanisms. By integrating sequence alignments and structural model comparisons, we developed a position-specific scoring matrix (PSSM) based on self-cleavage motifs, revealing specific preferences for each residue. Utilizing AlphaFold2's predicted alignment error (PAE) and predicted local distance difference test (pLDDT), we found that most cleavage sequences are located in regions with high PAE and low pLDDT values. KEGG pathway analysis showed that potential host protein cleavage targets are mainly concentrated in pathways related to nucleo-cytoplasmic transport and endocytosis. Through <em>in vitro</em> cleavage experiments and mutational analysis, we identified and validated three high-scoring proteins—nucleoporin 58 (NUP58), cell division cycle 73 (CDC73), and signal transducing adaptor molecule 2 (STAM2). These findings suggest that 3CL^pro not only plays a vital role in viral replication but may also influence host cell functions by cleaving host proteins. This study provides an effective tool for identifying 3CL^pro cleavage sites, revealing the pathogenic mechanisms of coronaviruses, and offering new insights for developing potential therapeutic targets.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142493886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CDR identification, epitope mapping and binding affinity determination of novel monoclonal antibodies generated against human apolipoprotein B-100","authors":"Tariga Sritrakarn ,&nbsp;Kanokwan Lowhalidanon ,&nbsp;Panida Khunkaewla","doi":"10.1016/j.bbapap.2024.141058","DOIUrl":"10.1016/j.bbapap.2024.141058","url":null,"abstract":"<div><div>In-house generated mAbs to apolipoprotein B-100 (apoB-100) clones hLDL-E8, hLDL-2D8 and hLDL-F5 were extensively studied to determine their complementarity-determining regions (CDRs), binding epitopes and affinity. RT-PCR revealed that all mAbs consisted of kappa light chains and gamma heavy chains. DNA sequencing and bioinformatic analysis showed that the variable gene and protein sequences of their CDRs shared over 50 % identity with the existing databases. The 3D structures of the mAb variable fragments (Fv) with a QSQE score above 0.7 were constructed using the SWISS-MODEL platform. The structural accuracy was confirmed by Ramachandran plots, with 99 % of amino acid residues falling within acceptable regions. Thrombolytic cleavage of apoB-100 and Western blot analysis demonstrated that hLDL-E8 and hLDL-F5 specifically bind to the T3 fragment (aa 1297–3249), whereas hLDL-2D8 binds to the T4 fragment (aa 1–1297). These findings were supported with epitope-binding assays using inhibition ELISA, which indicated that hLDL-E8 binds at different epitopes from hLDL-2D8 and has some overlap with hLDL-F5. Lastly, the binding affinity of the mAbs was examined by indirect ELISA. The average affinity constants (K_aff) for mAbs hLDL-2D8, hLDL-E8 and hLDL-F5 are 1.51 ± 0.69 × 10⁹ Mol⁻¹, 7.25 ± 3.56 × 10⁸ Mol⁻¹ and 4.39 ± 2.63 × 10⁶ Mol⁻¹, respectively. Additionally, the behavior of the antibodies in the dose-response curve revealed that hLDL-F5 may recognize two epitopes of apoB-100 or have very low binding affinity. In contrast, hLDL-2D8 and hLDL-E8 each recognize a single epitope. These findings provide information that will be useful when selecting mAbs for both laboratory and clinical research purposes.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142493885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of proton-coupled electron transfer from protein to heme in dehaloperoxidase","authors":"Mst Sharmin Aktar ,&nbsp;Nikhila Kashyap Dhanvantari Madhuresh ,&nbsp;Reza A. Ghiladi,&nbsp;Stefan Franzen","doi":"10.1016/j.bbapap.2024.141053","DOIUrl":"10.1016/j.bbapap.2024.141053","url":null,"abstract":"<div><div>At least two of the six methionine (Met) residues in dehaloperoxidase (DHP) are shown to act as electron donors in both autoreduction and protein-heme crosslinking. Autoreduction observed in the two isozymes, DHP-A and DHP-B, is explained by the high heme reduction potential and an endogenous source of electrons from methionine (Met) or cysteine (Cys). This study provides evidence of a connection to protein-heme crosslinking that occurs when DHP is activated by H₂O₂ in competition with substrate oxidation and autoreduction. The autoreduction yields of DHP-A and DHP-B are comparable and both are inversely proportional to DHP concentration. Both isoenzymes show an anti-cooperative effect on autoreduction kinetics associated with protein dimerization. Despite the presence of five tyrosine (Tyr) amino acids in DHP-A and four Tyr in DHP-B, the mass spectral evidence does not support a Tyr-heme or interprotein Tyr-Tyr crosslinking event as observed in some mammalian myoglobins. LC-MS and tandem MS/MS studies revealed three amino acids that were involved in the heme-protein crosslink, Cys73, Met63 and Met64. Cys73 facilitates dimer formation in DHP-A which also appears to slow the rate of autoreduction, but is not involved in covalent protein-heme crosslinking. Based on mutational studies, Met63 and 64 are involved in both covalent heme crosslinking and autoreduction. Proton-coupled electron transfer and crosslinking by Met to the heme may serve to regulate DHP function and protect it from uncontrolled oxidative damage.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142456983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incorporation of pyridoxal-5′-phosphate into the apoenzyme: A structural study of D-amino acid transaminase from Haliscomenobacter hydrossis","authors":"Alina K. Bakunova ,&nbsp;Ilya O. Matyuta ,&nbsp;Mikhail E. Minyaev ,&nbsp;Konstantin M. Boyko ,&nbsp;Vladimir O. Popov ,&nbsp;Ekaterina Yu. Bezsudnova","doi":"10.1016/j.bbapap.2024.141056","DOIUrl":"10.1016/j.bbapap.2024.141056","url":null,"abstract":"<div><div>Pyridoxal-5′-phosphate (PLP)-dependent transaminases are key enzymes of amino acid metabolism in cells and remarkable biocatalysts of stereoselective amination for process chemistry applications. As cofactor-dependent enzymes, transaminases are prone to cofactor leakage. Here we discuss the holoenzyme-apoenzyme interconversion and the kinetics of PLP incorporation into the apo form of a PLP-dependent transaminase from <em>Haliscomenobacter hydrossis</em>. PLP binding to the apoenzyme was slow in buffer, but was accelerated in the presence of substrates. Two crystal structures of the apoenzyme were obtained: the directly obtained apoenzyme (PDB ID: <span><span>7P8O</span><svg><path></path></svg></span>) and the one obtained by soaking crystals of the holoenzyme in a phenylhydrazine solution (PDB ID: <span><span>8YRU</span><svg><path></path></svg></span>). The mechanism of PLP association with the apoenzyme was proposed on the basis of structural analysis of these apo forms. Three rearrangement steps, including (I) anchoring of the PLP via the phosphate group, (II) displacement of two loops, and (III) Schiff-bonding between the PLP and the ε-amino group of the catalytic lysine residue, reconstituted the active holo form of the transaminase from <em>H. hydrossis</em>. The results obtained allowed us to determine in the active site a permanent part and elements that are assembled by PLP, these findings may be useful for transaminase engineering for biocatalysis.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142456984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ndufs4 knockout mice with isolated complex I deficiency engage a futile adaptive brain response","authors":"Melissa A.E. van de Wal ,&nbsp;Cenna Doornbos ,&nbsp;Janne M. Bibbe ,&nbsp;Judith R. Homberg ,&nbsp;Clara van Karnebeek ,&nbsp;Martijn A. Huynen ,&nbsp;Jaap Keijer ,&nbsp;Evert M. van Schothorst ,&nbsp;Peter A.C. 't Hoen ,&nbsp;Mirian C.H. Janssen ,&nbsp;Merel J.W. Adjobo-Hermans ,&nbsp;Mariusz R. Wieckowski ,&nbsp;Werner J.H. Koopman","doi":"10.1016/j.bbapap.2024.141055","DOIUrl":"10.1016/j.bbapap.2024.141055","url":null,"abstract":"<div><div>Paediatric Leigh syndrome (LS) is an early-onset and fatal neurodegenerative disorder lacking treatment options. LS is frequently caused by mutations in the <em>NDUFS4</em> gene, encoding an accessory subunit of mitochondrial complex I (CI), the first complex of the oxidative phosphorylation (OXPHOS) system. Whole-body <em>Ndufs4</em> knockout (KO) mice (WB-KO mice) are widely used to study isolated CI deficiency, LS pathology and interventions. These animals develop a brain-specific phenotype <em>via</em> an incompletely understood pathomechanism. Here we performed a quantitative analysis of the sub-brain proteome in six-weeks old WB-KO mice <em>vs.</em> wildtype (WT) mice. Brain regions comprised of a brain slice (BrSl), cerebellum (CB), cerebral cortex (CC), hippocampus (HC), inferior colliculus (IC), and superior colliculus (SC). Proteome analysis demonstrated similarities between CC/HC, and between IC/SC, whereas BrSl and CB differed from these two groups and each other. All brain regions displayed greatly reduced levels of two CI structural subunits (NDUFS4, NDUFA12) and an increased level of the CI assembly factor NDUFAF2. The level of CI-Q module subunits was significantly more reduced in IC/SC than in BrSl/CB/CC/HC, whereas other OXPHOS complex levels were not reduced. Gene ontology and pathway analysis demonstrated specific and common proteome changes between brain regions.</div><div>Across brain regions, upregulation of cold-shock-associated proteins, mitochondrial fatty acid (FA) oxidation and synthesis (mtFAS) were the most prominent. FA-related pathways were predominantly upregulated in CB and HC. Based upon these results, we argue that stimulation of these pathways is futile and pro-pathological and discuss alternative strategies for therapeutic intervention in LS.</div></div><div><h3>Significance</h3><div>The <em>Ndufs4</em> knockout mouse model is currently the most relevant and most widely used animal model to study the brain-linked pathophysiology of human Leigh Syndrome (LS) and intervention strategies. We demonstrate that the <em>Ndufs4</em> knockout brain engages futile and pro-pathological responses. These responses explain both negative and positive outcomes of intervention studies in Leigh Syndrome mice and patients, thereby guiding novel intervention opportunities.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142456982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphoproteome modulation by nucleoside diphosphate kinase affects photosynthesis & stress tolerance of Nostoc PCC 7120","authors":"Anurag Kirti ,&nbsp;Hema Rajaram","doi":"10.1016/j.bbapap.2024.141054","DOIUrl":"10.1016/j.bbapap.2024.141054","url":null,"abstract":"<div><div>Nucleoside diphosphate kinase (Ndk/NDK/NDPK) is known to possess pleiotropic functions, one of which is that as a protein kinase, and has been shown to be involved in stress tolerance in plants. To assess its role in the cyanobacterium <em>Nostoc</em> PCC 7120, which is hitherto unreported, recombinant strain overexpressing Ndk, An<em>ndk</em>^<em>+</em> was generated. Phosphoproteomic analysis of An<em>ndk</em>⁺ and its comparison with that of the vector control, AnpAM, revealed differential phosphorylation at S/T/Y sites of proteins belonging to varied functional groups, with over 17 % phosphoproteins involved in photosynthesis. A total of 177 phosphopeptides and 117 phosphoproteins were identified, including newly identified phosphopeptides in any cyanobacteria. Compared to AnpAM, the An<em>ndk</em>⁺ cells exhibited (i) lower photosynthetic efficiency and electron transport rate at low PAR (photosynthetically active radiation), (ii) no change in photochemical quenching across PAR, (iii) but distinct non-photochemical quenching [zero Y(NPQ) and high Y(NO) in An<em>ndk</em>⁺ and high Y(NPQ) and low (NO) in AnpAM], and (iv) increased tolerance to γ-radiation, oxidative, salt and DCMU stresses. The observed modulation of phosphoproteome linked to physiological changes upon overexpression of Ndk in <em>Nostoc</em> could be a combination of direct protein kinase activity of Ndk and/or indirectly through other protein kinases and phosphatases whose phosphorylation status is mediated by Ndk. This is the first report on a direct correlation between Ndk levels, phosphorylation status of proteins and stress tolerance in any cyanobacteria.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of adipocyte differentiation based on proteomics and intact N-glycopeptide modificationomics","authors":"Xin-Yu Li ,&nbsp;Nuerbiye Nuermaimaiti ,&nbsp;Xuanyu Meng ,&nbsp;Xiaozheng Zhang ,&nbsp;Aikedaimu Abudukeremu ,&nbsp;Yihuai He ,&nbsp;Wenting Ma ,&nbsp;Xuelei Chen ,&nbsp;Shangkun Li ,&nbsp;Jiaxin Sun ,&nbsp;Yaqun Guan","doi":"10.1016/j.bbapap.2024.141052","DOIUrl":"10.1016/j.bbapap.2024.141052","url":null,"abstract":"<div><h3>Objective</h3><div>To investigate the role of N-glycosylation modification of proteins in adipocyte differentiation during the adipogenic process.</div></div><div><h3>Methods</h3><div>SVF cells and adipocytes were analyzed for proteomics and intact N-glycopeptide modificationomics.Differential expression of proteins, glycoforms, and sites between the two groups was screened and subjected to Gene Ontology (GO) functional enrichment analysis, KEGG pathway enrichment analysis, and protein-protein interaction (PPI) network analysis. The top 20 most significantly differentially expressed adipogenic differentiation-related proteins were identified, and the most pronouncedly altered proteins were analyzed for glycoforms, glycan chains, and sites.</div></div><div><h3>Results</h3><div>Proteomics analysis identified 39,392 peptides and 5208 proteins, while intact N-glycopeptide modification profiling identified 3293 intact glycopeptides, 426 proteins, and 161 glycan chains. Proteomics identified 2510 differentially expressed proteins, with CD36 (Cluster of Differentiation 36, CD36) significantly upregulated. In adipocytes, CD36 had 4 N-glycosylation sites: N79, N220, N320, N417, with N320 being a newly identified site. GO enrichment results indicated that CD36 is associated with fatty acid oxidation, lipid oxidation, and fatty acid uptake into cells.</div></div><div><h3>Conclusion</h3><div>Multiple proteins undergo N-glycosylation modification during adipocyte differentiation, with CD36, a fatty acid translocase, being significantly expressed in adipocytes. This suggests that N-glycosylation modification of CD36 may play a crucial role in adipocyte differentiation, providing a foundation for further investigation into the function of CD36 N-glycosylation in adipocyte differentiation.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142387571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural insights into the mechanism underlying the dual cofactor specificity of glyoxylate reductase from Acetobacter aceti in the β-hydroxyacid dehydrogenase family","authors":"Toma Rani Majumder ,&nbsp;Takuya Yoshizawa ,&nbsp;Masao Inoue ,&nbsp;Riku Aono ,&nbsp;Hiroyoshi Matsumura ,&nbsp;Hisaaki Mihara","doi":"10.1016/j.bbapap.2024.141051","DOIUrl":"10.1016/j.bbapap.2024.141051","url":null,"abstract":"<div><div>The β-hydroxyacid dehydrogenase family exhibits diverse cofactor preferences: some enzymes favor NAD, others favor NADP, and a subset can utilize both NAD and NADPH. Glyoxylate reductase from <em>Acetobacter aceti</em> JCM 20276 (AacGR) exhibits a dual cofactor specificity for NADPH and NADH in its catalytic reduction of glyoxylate to glycolate. In contrast to conventional cofactor-discriminating motifs, NRX and DXX, found in NADP- and NAD-specific enzymes, respectively, AacGR has a TPS motif in the equivalent position. Here we report X-ray crystallographic analysis of AacGR in its ligand-free form, and in complexes with NADPH and NADH, revealing critical interactions: Ser41 of the TPS motif interacted with the 2′-phosphate group of NADPH, while no analogous interaction occurred with the ribose hydroxy groups of NADH. Moreover, the TPS motif resided within a characteristic β-turn-like structure adjacent to a long flexible loop. Site-directed mutagenesis and kinetic analyses suggest that Ser41 facilitates NADPH binding, while the lack of a direct interaction of the TPS motif with NADH may allow for NADH utilization. The conformational dynamics of the TPS-containing β-turn-like structure along with the flexible loop likely govern the dual cofactor specificity and catalytic turnover of AacGR.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and functional studies of Avt1, a novel peptide from the sea anemone Aulactinia veratra","authors":"Renad A. Albar ,&nbsp;Hayden L. Smith ,&nbsp;Karoline Sanches ,&nbsp;Dorothy C.C. Wai ,&nbsp;Muhammad Umair Naseem ,&nbsp;Tibor G. Szanto ,&nbsp;Gyorgy Panyi ,&nbsp;Peter J. Prentis ,&nbsp;Raymond S. Norton","doi":"10.1016/j.bbapap.2024.141050","DOIUrl":"10.1016/j.bbapap.2024.141050","url":null,"abstract":"<div><div>Sea anemones are a rich source of peptide toxins spanning a diverse range of biological activities, typically targeting proteins such as ion channels, receptors and transporters. These peptide toxins and their analogues are usually highly stable and selective for their molecular targets, rendering them of interest as molecular tools, insecticides and therapeutics. Recent transcriptomic and proteomic analyses of the sea anemone <em>Aulactinia veratra</em> identified a novel 28-residue peptide, designated Avt1. Avt1 was produced using solid-phase peptide synthesis, followed by oxidative folding and purification of the folded peptide using reversed-phase high-performance liquid chromatography. The liquid chromatography-mass spectrometry profile of synthetic Avt1 showed a pure peak with molecular mass 6 Da less than that of the reduced form of the peptide, indicating the successful formation of three disulfide bonds. The solution structure determined by NMR revealed that Avt1 adopts an inhibitor cystine knot (ICK) fold, in which a ring is formed by two disulfide bonds with a third disulfide penetrating the ring to create the pseudo-knot. This structure provides ICK peptides with high structural, thermal and proteolytic stability. Consistent with its ICK structure, Avt1 was resistant to proteolysis by trypsin, chymotrypsin and pepsin, although it was not a trypsin inhibitor. Avt1 at 100 nM showed no activity in patch–clamp electrophysiological assays against several mammalian voltage-gated ion channels, but has structural features similar to toxins targeting insect sodium ion channels. Although sequence homologues of Avt1 are found in a number of sea anemones, this is the first representative of this family to be characterised structurally and functionally.</div></div>","PeriodicalId":8760,"journal":{"name":"Biochimica et biophysica acta. Proteins and proteomics","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142364212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}