Biomedica biochimica acta最新文献_第9页

S-S bridges of cathepsin B and H from bovine spleen: a basis for cathepsin B model building and possible functional implications for discrimination between exo- and endopeptidase activities among cathepsins B, H and L. 牛脾脏组织蛋白酶B和H的S-S桥:建立组织蛋白酶B模型的基础，以及组织蛋白酶B、H和L之间外肽酶和内肽酶活性区分的可能功能意义。

Biomedica biochimica acta Pub Date : 1991-01-01

M Baudys, B Meloun, T Gan-Erdene, M Fusek, M Mares, V Kostka, J Pohl, C C Blake

{"title":"S-S bridges of cathepsin B and H from bovine spleen: a basis for cathepsin B model building and possible functional implications for discrimination between exo- and endopeptidase activities among cathepsins B, H and L.","authors":"M Baudys, B Meloun, T Gan-Erdene, M Fusek, M Mares, V Kostka, J Pohl, C C Blake","doi":"","DOIUrl":"","url":null,"abstract":"Bovine spleen cathepsin B contains 7 disulfide bridges. Using different chemical and enzymatic cleavage methods we isolated fragments representing the individual disulfides: Cys14-Cys43, Cys26-Cys71, Cys62-Cys128, Cys63-Cys67, Cys100-Cys132, Cys108-Cys119, and Cys148-Cys252. A similar line of approach was applied to determine the S-S bridges of bovine spleen cathepsin H: Cys23-Cys66, Cys57-Cys99, Cys157-Cys207, and Cys212-Cys5A, where Cys5A is located in the propart portion of the procathepsin H chain. On the basis of the knowledge of the S-S bridges of cathepsin B a novel sequence alignment of papain and cathepsin B has been proposed. This enabled us to construct a reasonable 3D-model of cathepsin B and propose the region (a 18 residue insertion between Glu89 and Gly90 of papain) responsible for the carboxypeptidase activity of cathepsin B functioning as a \"closure\". A similar approach was applied to explain the aminopeptidase activity of cathepsin H. A general model of steric regulation of accessibility of the preformed \"endopeptidase-like\" binding cleft by distant parts of the polypeptide chain of the proteinases discussed is proposed as a factor determining the mode of binding and thus cleavage of polypeptide substrates.","PeriodicalId":8948,"journal":{"name":"Biomedica biochimica acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12965121","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: 0

Molecular mechanism of inhibition of cysteine proteinases by their protein inhibitors: kinetic studies with natural and recombinant variants of cystatins and stefins. 半胱氨酸蛋白酶蛋白抑制剂抑制半胱氨酸蛋白酶的分子机制:天然和重组半胱氨酸和胱氨酸的动力学研究。

Biomedica biochimica acta Pub Date : 1991-01-01

W Machleidt, U Thiele, I Assfalg-Machleidt, D Förger, E A Auerswald

{"title":"Molecular mechanism of inhibition of cysteine proteinases by their protein inhibitors: kinetic studies with natural and recombinant variants of cystatins and stefins.","authors":"W Machleidt, U Thiele, I Assfalg-Machleidt, D Förger, E A Auerswald","doi":"","DOIUrl":"","url":null,"abstract":"Natural and recombinant variants of the cysteine proteinase inhibitors chicken cystatin and human stefin B were characterized by determination of their inhibition constants for papain, actinidin and human cathepsins B and H. The individual contributions of the three contact regions to the binding energy of the chicken cystatin-papain complex were calculated as 36% for the N-terminal segment, 51% for the first and 13% for the second hairpin loop. Removal of the N-terminal contact region of chicken cystatin resulted in a 10000-fold lower affinity for papain. In contrast, stefin B remained a tight-binding inhibitor of papain and actinidin without its N-terminal segment. Affinity of stefin B for papain was only slightly affected by exchange of the residue predicted to bind in the S2 subsite of papain. The essential contribution of the first hairpin loop to inhibitor binding was confirmed by the 240-fold lower affinity for papain of a Val48----Asp mutant of stefin B. Inhibition of cathepsin B by stefins A and B is slow-binding. Binding of stefin B, not of stefin A, follows a two-step mechanism involving a slow isomerisation of the enzyme-inhibitor complex.","PeriodicalId":8948,"journal":{"name":"Biomedica biochimica acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12965127","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: 0

Serum albumin stimulates the reactivation of bovine lens epithelial cells in primary culture. 血清白蛋白刺激原代培养的牛晶状体上皮细胞的再活化。

Biomedica biochimica acta Pub Date : 1991-01-01

D Glaesser, M Iwig

引用次数: 0

New enzymatic protecting group techniques for the construction of peptides and glycopeptides. 构建肽和糖肽的新酶保护基团技术。

Biomedica biochimica acta Pub Date : 1991-01-01

H Waldmann, P Braun, H Kunz

引用次数: 0

Principles of the molecular construction of multienzyme templates for peptide biosynthesis in integrated reaction sequences. 综合反应序列中多肽生物合成多酶模板的分子结构原理。

Biomedica biochimica acta Pub Date : 1991-01-01

H van Liempt, E Pfeifer, T Schwecke, H Palissa, H von Doehren

引用次数: 0

Cell-free biosynthesis of cyclosporin A and analogues. 环孢素A及其类似物的无细胞生物合成。

Biomedica biochimica acta Pub Date : 1991-01-01

H Kleinkauf, J Dittmann, A Lawen

{"title":"Cell-free biosynthesis of cyclosporin A and analogues.","authors":"H Kleinkauf, J Dittmann, A Lawen","doi":"","DOIUrl":"","url":null,"abstract":"The final assembly of the 11-peptide chain of cyclosporins and its cyclization is accomplished in the producer Beauveria nivea by cyclosporine synthetase. This multienzyme represents the largest integrated enzyme structure reported so far. Its size has been estimated to approximately 1,500 kDa by SDS-PAGE. Some enzyme bound linear peptides could be isolated and identified. All of them represent partial sequences of cyclosporin A starting with D-alanine. These peptides were bound by thioester linkage to the enzyme. This could be demonstrated by liberation of the peptides with performic acid and by inhibition of in vitro cyclosporin A synthesis with thiol blocking agents. Cyclosporin synthetase is capable to synthesize besides a lot of cyclosporins known from fermentation studies some new cyclosporins so far not obtainable by fermentation. So, for example the synthesis of [N-methyl-(+)-2-amino-3-hydroxy-4,4-dimethyloctanoic acid1]CyA, Dihydro-CyA, [L-norvaline2,5, N-methyl-L-norvaline11]CyA, [L-allo-isoleucine5, N-methyl-L-allo-isoleucine11]CyA, [D-2-aminobutyric acid8]CyA, [beta-chloro-D-alanine8]CyA and some related compounds could be established. We were able to synthesize these cyclosporins in sufficient quantities to ensure their structure by fast atom bomdardment mass spectroscopy and to examine their immunosuppressitivity. All new cyclosporins synthesized in the in vitro system so far are immunosuppressive.","PeriodicalId":8948,"journal":{"name":"Biomedica biochimica acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12981722","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: 0

Kinetics of 6-phosphofructo-1-kinase from a yeast mutant. 酵母突变体6-磷酸果糖激酶的动力学研究。

Biomedica biochimica acta Pub Date : 1991-01-01

M Bigl, K Eschrich, E Hofmann

{"title":"Kinetics of 6-phosphofructo-1-kinase from a yeast mutant.","authors":"M Bigl, K Eschrich, E Hofmann","doi":"","DOIUrl":"","url":null,"abstract":"The steady state kinetics of 6-phosphofructo-1-kinase was determined in a cell-free extract obtained from a yeast mutant (DFY 250) and compared with the kinetic properties of the enzyme of a wild-type strain (DFY 1). 6-Phosphofructo-1-kinase from the DFY 250 strain shows a complex kinetic behaviour, which is qualitatively similar to, but quantitatively different from, that of normal yeast 6-phosphofructo-1-kinase. The mutant enzyme has a lower affinity to its activators fructose 6-phosphate, fructose 2,6-bisphosphate and AMP. The inhibiting effect of ATP on the mutant 6-phosphofructo-1-kinase is substantially weaker than on the wild-type enzyme. A complex interaction between fructose 6-phosphate and fructose 2,6-bisphosphate at the 6-phosphofructo-1-kinase from strain DFY 250 is reflected by a remarkable substrate inhibition by fructose 6-phosphate even at saturating fructose 2,6-bisphosphate. The kinetic data were fitted to different variants of the Monod-Wyman-Changeux model by nonlinear regression analysis. It turned out that the influence of fructose 6-phosphate, ATP, AMP and fructose 2,6-bisphosphate on the activity of 6-phosphofructo-1-kinase from wild-type and DFY 250 strain could be described by rate equations of essentially the same structure.","PeriodicalId":8948,"journal":{"name":"Biomedica biochimica acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12996973","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: 0

Lipoxygenases from soybeans and rabbit reticulocytes: inactivation and iron release. 大豆和兔网状细胞中的脂氧合酶：失活和铁释放。

Biomedica biochimica acta Pub Date : 1991-01-01

W E Höhne, N Kojima, B Thiele, S M Rapoport

{"title":"Lipoxygenases from soybeans and rabbit reticulocytes: inactivation and iron release.","authors":"W E Höhne, N Kojima, B Thiele, S M Rapoport","doi":"","DOIUrl":"","url":null,"abstract":"Various inactivation methods were applied to lipoxygenases from soybean (isoenzyme 1) and rabbit reticulocytes to compare the inactivation behaviour of both enzymes and to elucidate the state of the iron which is known to be involved in the catalytic reaction of lipoxygenases: 1. Titration of the enzyme with mercury compounds shows that there are one or two SH groups responsible for the loss of activity in the presence of mercury. The SH groups seem not to be involved in the tight iron binding. 2. Inactivation by chelating agents such as o-phenanthroline or batho-phenanthroline sulfonic acid occurs only in the presence of reducing agents (mercaptoethanol and ascorbic acid). Our data support a co-oxidation mechanism. The complexation of iron by chelators is not the rate-limiting step. Both lipoxygenases show a very similar behaviour in this respect despite the fact that the reticulocyte enzyme requires the addition of trace amounts of copper ions for efficient inactivation. 3. Release of iron from the enzyme is also achieved by denaturation with guanidinium hydrochloride (Gu-HCl). In all cases, inactivation and release of iron were irreversible processes. 4. A sequence comparison for both animal and plant lipoxygenases shows strongly conserved amino acids, especially histidines and hydrophobic residues, which possibly may be involved in iron complexation and substrate binding.","PeriodicalId":8948,"journal":{"name":"Biomedica biochimica acta","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13067895","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: 0

A comparative study of electrolyte and water transport in the rabbit ileum and colon in vitro and in vivo: influence of D-glucose. 体外和体内家兔回肠和结肠中电解质和水转运的比较研究:d -葡萄糖的影响。

Biomedica biochimica acta Pub Date : 1991-01-01

M S Campos, M C Galindo, J A García, F Lisbona, I López-Aliaga

引用次数: 0

Proteolysis of defensive proteins in peritonitis exudate 腹膜炎渗出物中防御蛋白的蛋白水解

Biomedica biochimica acta Pub Date : 1991-01-01 DOI: 10.5282/UBM/EPUB.9805

A. Billing, D. Fröhlich, I. Assfalg‐Machleidt, W. Machleidt, M. Jochum

引用次数: 1