Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology最新文献_第8页

Unfolding the unique c-type heme protein, Chlamydomonas reinhardtii cytochrome f 揭示独特的c型血红素蛋白，莱茵衣藻细胞色素f

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-01 DOI: 10.1016/S0167-4838(02)00214-5

Ali Sabahi, Pernilla Wittung-Stafshede

{"title":"Unfolding the unique c-type heme protein, Chlamydomonas reinhardtii cytochrome f","authors":"Ali Sabahi, Pernilla Wittung-Stafshede","doi":"10.1016/S0167-4838(02)00214-5","DOIUrl":"10.1016/S0167-4838(02)00214-5","url":null,"abstract":"<div>We have studied the unfolding reaction of cytochrome f from the green alga Chlamydomonas reinhardtii. Cytochrome f is different from all other c-type heme proteins in that it is a large, two-domain protein with predominantly β-sheet structure. Moreover, the sixth axial ligand to the heme-iron is unique in cytochrome f: it is provided by the N-terminal α-amino group. Unfolding of oxidized and reduced cytochrome f by guanidine hydrochloride (GuHCl) was monitored by far-UV circular dichroism (CD), Soret absorption, and tyrosine emission: the same unfolding curves were obtained regardless of method. Neither oxidized nor reduced unfolded cytochrome f can be refolded at neutral pH. At pH 3.5 refolding takes place (upon dilution to lower denaturant concentrations or by electron injection to the unfolded, oxidized form), although the reaction is extremely slow. Reduced cytochrome f appears much more resistant towards denaturant perturbation than the oxidized form (in pH range 7–3.5). The heme in unfolded cytochrome f remains low-spin to pH 4 but turns high-spin at pH 3.5 (presumably due to protonation of the N-terminal amino group). Our results suggest that the unfolding process for cytochrome f is complex, involving kinetically trapped intermediates not resolvable by spectroscopy.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00214-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77183842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

In vitro stepwise autoprocessing of the proform of pro-aminopeptidase processing protease from Aeromonas caviae T-64 洞穴气单胞菌T-64前氨基肽酶加工蛋白酶形态的体外分步自动加工

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-01 DOI: 10.1016/S0167-4838(01)00315-6

Bing Tang, Satoru Nirasawa, Motomitsu Kitaoka, Kiyoshi Hayashi

{"title":"In vitro stepwise autoprocessing of the proform of pro-aminopeptidase processing protease from Aeromonas caviae T-64","authors":"Bing Tang, Satoru Nirasawa, Motomitsu Kitaoka, Kiyoshi Hayashi","doi":"10.1016/S0167-4838(01)00315-6","DOIUrl":"10.1016/S0167-4838(01)00315-6","url":null,"abstract":"<div>PA protease (pro-aminopeptidase processing protease) is an extracellular zinc metalloprotease produced by the Gram-negative bacterium Aeromonas caviae T-64. The 590-amino-acid precursor of PA protease is composed of a putative 19-amino-acid signal sequence, a 165-amino-acid N-terminal propeptide, a 33 kDa mature protease domain and an 11 kDa C-terminal propeptide. The proform of PA protease, which was produced as inclusion bodies in Escherichia coli, was subjected to in vitro refolding. It was revealed that the processing of the proform involved a stepwise autoprocessing mechanism. Firstly, the N-terminal propeptide was autocatalytically removed on completion of refolding and secondly, the C-terminal propeptide was autoprocessed after the degradation of the N-terminal propeptide. Both the N- and C-terminal propeptides existed as intact peptides after their successive removal, and they were subsequently degraded gradually. The degradation of the N-terminal propeptide appears to be the rate-limiting step in the maturation of the proform of PA protease.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00315-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79672191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

The receptor docking segment and S-adenosyl-L-homocysteine bind independently to the methyltransferase of bacterial chemotaxis 受体对接段和s -腺苷- l-同型半胱氨酸独立结合细菌趋化性甲基转移酶

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-01 DOI: 10.1016/S0167-4838(01)00314-4

X. Yi, R.M. Weis

{"title":"The receptor docking segment and S-adenosyl-L-homocysteine bind independently to the methyltransferase of bacterial chemotaxis","authors":"X. Yi, R.M. Weis","doi":"10.1016/S0167-4838(01)00314-4","DOIUrl":"10.1016/S0167-4838(01)00314-4","url":null,"abstract":"<div>To mediate adaptation to stimuli, the methyltransferase (CheR) catalyzes methyl group transfer from S-adenosyl-L-methionine (SAM) to glutamyl residues in the transmembrane receptors of the bacterial chemosensory signaling pathway. The interaction between receptors and CheR occurs at two sites: a methylation site–active site interaction, and a ‘docking’ site interaction that is separated both from the methylation sites and the CheR active site. It is not certain if the docking site interaction functions merely to localize the transferase in close proximity to the methylation sites, or if it also increases CheR catalytic activity. Isothermal titration calorimetry experiments are conducted to test for allosteric interactions between the docking and active sites on CheR, which are expected to be present if docking activates CheR. The binding parameters (ΔG, ΔH, ΔS) of a substrate analog of SAM, S-adenosyl-L-homocysteine (SAH), are measured both in the absence and presence of saturating concentrations of a pentapeptide (NWETF) that defines the docking receptor docking segment. SAH binding is unaffected by the presence of saturating NWETF, providing evidence that an allosteric activation of CheR does not take place upon docking, and thus supports the idea that the CheR–NWETF interaction merely functions to localize CheR near the sites of methylation.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00314-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77368296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Unraveling multistate unfolding of rabbit muscle creatine kinase 揭示兔肌肌酸激酶的多态展开

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-01 DOI: 10.1016/S0167-4838(02)00212-1

Irina M Kuznetsova , Olga V Stepanenko, Konstantin K Turoverov , Li Zhu , Jun-Mei Zhou , Anthony L Fink , Vladimir N Uversky

{"title":"Unraveling multistate unfolding of rabbit muscle creatine kinase","authors":"Irina M Kuznetsova , Olga V Stepanenko, Konstantin K Turoverov , Li Zhu , Jun-Mei Zhou , Anthony L Fink , Vladimir N Uversky","doi":"10.1016/S0167-4838(02)00212-1","DOIUrl":"10.1016/S0167-4838(02)00212-1","url":null,"abstract":"<div>GdmCl-induced unfolding of rabbit muscle creatine kinase, CK, has been studied by a variety of physico-chemical methods including near and far UV CD, SEC, intrinsic fluorescence (intensity, anisotropy and lifetime) as well as intensity and lifetime of bound ANS fluorescence. The formation of several stable unfolding intermediates, some of which were not observed previously, has been established. This was further confirmed by representation of fluorescence data in terms of ‘phase diagram’, i.e. Iλ1 versus Iλ2 dependence, where Iλ1 and Iλ2 are fluorescence intensity values measured on wavelengths λ1 and λ2 under the different experimental conditions for a protein undergoing structural transformations. The unfolding behavior of CK was shown to be strongly affected by association of partially folded intermediates. A model of CK unfolding, which takes into account both structural perturbations and association of partially folded intermediates has been elaborated.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(02)00212-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77744065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 87

Unfolding of pyridoxal 5′-phosphate-dependent O-acetylserine sulfhydrylase probed by time-resolved tryptophan fluorescence 时间分辨色氨酸荧光探测吡哆醛5 ' -磷酸依赖的o -乙酰丝氨酸巯基化酶的展开

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-04-01 DOI: 10.1016/S0167-4838(01)00316-8

Stefano Bettati , Barbara Campanini , Simona Vaccari , Andrea Mozzarelli , Giulio Schianchi , Theodore L. Hazlett , Enrico Gratton , Sara Benci

{"title":"Unfolding of pyridoxal 5′-phosphate-dependent O-acetylserine sulfhydrylase probed by time-resolved tryptophan fluorescence","authors":"Stefano Bettati , Barbara Campanini , Simona Vaccari , Andrea Mozzarelli , Giulio Schianchi , Theodore L. Hazlett , Enrico Gratton , Sara Benci","doi":"10.1016/S0167-4838(01)00316-8","DOIUrl":"10.1016/S0167-4838(01)00316-8","url":null,"abstract":"<div>Proteins utilizing pyridoxal 5′-phosphate as a coenzyme constitute a large superfamily and are currently classified into three functional groups and five structural fold types. Despite the variability of sequences and catalyzed reactions, they share relevant structural, dynamic and functional properties. Therefore, they constitute an optimal system to investigate the relative influence of primary sequence and coenzyme interactions on folding pathways, structural stability and enzymatic function. O-Acetylserine sulfhydrylase is a dimeric pyridoxal 5′-phosphate dependent enzyme that catalyzes the synthesis of l-cysteine from O-acetylserine and sulfide. The time-resolved fluorescence study of O-acetylserine sulfhydrylase unfolding, here reported, indicates that the coenzyme stabilizes the protein structure. The dependence on denaturant concentration of tryptophan lifetimes in the holo- and apo-enzyme demonstrates that the interactions with the coenzyme stabilize the C-terminal domain to a higher extent with respect to the N-terminal domain. This result is discussed in terms of a linkage between the differential stabilization brought about by the coenzyme and the different degrees of conformational flexibility required by the specialized functional role of distinct protein regions.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00316-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83974285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Cold denaturation of proteins under high pressure 蛋白质在高压下的冷变性

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-03-25 DOI: 10.1016/S0167-4838(01)00354-5

Shigeru Kunugi, Naoki Tanaka

引用次数: 131

Exploring hyperthermophilic proteins under pressure: theoretical aspects and experimental findings 探索压力下的超嗜热蛋白:理论方面和实验结果

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-03-25 DOI: 10.1016/S0167-4838(01)00361-2

Enrico Mombelli , Erlet Shehi , Paola Fusi , Paolo Tortora

{"title":"Exploring hyperthermophilic proteins under pressure: theoretical aspects and experimental findings","authors":"Enrico Mombelli , Erlet Shehi , Paola Fusi , Paolo Tortora","doi":"10.1016/S0167-4838(01)00361-2","DOIUrl":"10.1016/S0167-4838(01)00361-2","url":null,"abstract":"<div>Proteins from hyperthermophilic microorganisms are generally capable of withstanding temperatures close to, or even higher than the boiling point. As a rule, these proteins are strongly piezostable as well, although exceptions have been also reported. This observation has a theoretical relevance, as the understanding of the effects of pressure and temperature on protein stability is equally important to develop a comprehensive model for their thermodynamic stability. Nevertheless, the structural features justifying the correlation between heat resistance and pressure resistance are poorly understood. Actually, most reports do not exceed the phenomenological level. Only in the case of the small protein Sso7d from Sulfolobus solfataricus, characterisation of wild-type and some mutants showed that both properties are largely accounted for by a network of aromatic residues found in the hydrophobic core of the molecule. Current knowledge, however, does not allow to establish to what extent this finding may be generalised. In a biotechnological perspective, hyperthermophilic enzymes seem to be more suitable for bioprocesses at high pressure with respect to their mesophilic counterparts. Indeed, thanks to their higher resistance towards pressure and temperature, they may be exploited in a much broader range of working conditions for tuning activity and specificity. Furthermore, they are often activated by increasing pressure, although it cannot be established, to date, to what extent this is a common feature.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00361-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82188288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 32

Compressibility gives new insight into protein dynamics and enzyme function 可压缩性为蛋白质动力学和酶功能提供了新的见解

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-03-25 DOI: 10.1016/S0167-4838(01)00358-2

Kunihiko Gekko

引用次数: 59

The interactions of nucleic acids at elevated hydrostatic pressure 核酸在高静水压力下的相互作用

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-03-25 DOI: 10.1016/S0167-4838(01)00349-1

Robert B Macgregor Jr.

引用次数: 63

High pressure, a tool for exploring heme protein active sites 高压，探索血红素蛋白活性位点的工具

Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology Pub Date : 2002-03-25 DOI: 10.1016/S0167-4838(01)00352-1

Gaston Hui Bon Hoa , Mark A McLean , Stephen G Sligar

{"title":"High pressure, a tool for exploring heme protein active sites","authors":"Gaston Hui Bon Hoa , Mark A McLean , Stephen G Sligar","doi":"10.1016/S0167-4838(01)00352-1","DOIUrl":"10.1016/S0167-4838(01)00352-1","url":null,"abstract":"<div>High pressure is an interesting and suitable parameter in the study of the dynamics and stability of proteins. The effects of pressure on proteins delineates its volumic (ΔV°) and energetic (ΔG°) parameters. An enormous amount of effort has been invested by several laboratories in developing basic theory and high pressure techniques that allow the determination of barotropic parameters. Cytochrome P450s, one of the largest super families of heme proteins, are good models for high pressure studies. Two distinct pressure-induced spin transitions of the heme iron in the active site and a P450 to P420 inactivation process have been characterized. The obtained reaction volumes of these two processes for a series of analog-bound cytochrome P450s are compared. We have shown that both the spin volume and the inactivation volume are dependent on the substrate analogs which are known to modulate the polarity and hydration of the heme pocket. Several linear correlations were found between these reaction volumes and the physico-chemical properties of the heme protein such as the polarity-induced exposure of tyrosines, the hydration of the cytochrome CYP101 heme pocket, and the mobility and binding of the substrates indicate that they constitute the main contribution to the complex thermodynamic reaction volume parameters. This interpretation allows us to conclude that cytochrome CYP101, CYP2B4 and CYP102 possess a similar mechanism of substrate binding. Interestingly the barotropic behaviors of monomeric cytochrome P450s are quite different from those of oligomeric and hetorooligomeric cytochrome P450s. The interactions of heterooligomeric subunits influence the stability of individual cytochrome P450s and the asymmetric organization of subunits which can control and modulate the activity and the recognition with NADPH–cytochrome P450 reductase.</div>","PeriodicalId":100166,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2002-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0167-4838(01)00352-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82857022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 47