Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation最新文献

{"title":"The threonine-sensitive homoserine dehydrogenase and aspartokinase activities of Escherichia coli","authors":"Paolo Truffa-Bachi,&nbsp;Gérard Le Bras,&nbsp;Georges N. Cohen","doi":"10.1016/0926-6593(66)90004-X","DOIUrl":"10.1016/0926-6593(66)90004-X","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. Homoserine dehydrogenase I (<span>L</span>-homoserine: NADP⁺ oxidoreductase, EC 1.1.1.3) of <em>Escherichia coli</em> is inactivated in two steps by <span><math><mtext>p-</mtext><mtext>mercuribenzoic</mtext></math></span> acid (PMB). The first inactivation step is accompanied by desensitization of the enzyme activity towards its allosteric effector, <span>L</span>-threonine. The desensitized dehydrogenase activity is protected against further action of PMB by its own substrates and by the substrates of the associated activity, aspartokinase I (ATP:<span>L</span>-aspartate 4-phosphotransferase, EC 2.7.2.4).</p></span></li><li><span>2.</span><span><p>2. ATP and aspartate, the substrates of the kinase reaction induce conformational changes in the part of the complex enzyme molecule responsible for the dehydrogenase atalytic activity.</p></span></li></ul></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90004-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88495579","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}

{"title":"On the mechanism of ageing of phosphonylated cholinesterases","authors":"H.P. Benschop,&nbsp;J.H. Keijer","doi":"10.1016/0926-6593(66)90023-3","DOIUrl":"10.1016/0926-6593(66)90023-3","url":null,"abstract":"","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90023-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82422875","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}

{"title":"Mechanism of thiosulfate oxidation by Thiobacillus novellus","authors":"A. Michael Charles ,&nbsp;Isamu Suzuki","doi":"10.1016/0926-6593(66)90012-9","DOIUrl":"10.1016/0926-6593(66)90012-9","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. Whole cells and cell-free extracts of <em>Thiobacillus novellus</em> oxidized thiosulfate to sulfate without intermediary accumulation of sulfur of polythionates, consuming 2 moles of O₂ for every mole of thiosulfate oxidized.</p></span></li><li><span>2.</span><span><p>2. Tetrathionate was oxidized to sulfate by whole cells, but not by cell-free extracts.</p></span></li><li><span>3.</span><span><p>3. Sulfite was rapidly oxidized by whole cells and extracts to sulfate, consuming 0.5 mole of O₂ for every mole of sulfite oxidized. The oxidation was catalyzed by sulfite oxidase (sulfite: cytochrome <span><math><mtext>c</mtext></math></span> oxidoreductase) and cytochrome oxidase (cytochrome <span><math><mtext>c</mtext></math></span>: O₂ oxidoreductase, EC 1.9.3.1) as shown by manometric as well as spectrophotometric experiments.</p></span></li><li><span>4.</span><span><p>4. Elemental sulfur was oxidized by whole cells to sulfate, but the oxidation by extracts required the addition of GSH.</p></span></li><li><span>5.</span><span><p>5. Rhodanese (thiosulfate: cyanide sulfur transferase, EC 2.8.1.1) was found in the extracts which reduced cytochrome <span><math><mtext>c</mtext></math></span> within thiosulfate only in the presence of cyanide.</p></span></li><li><span>6.</span><span><p>6. The following reactions are proposed for the oxidation of thiosulfate by <em>T. novellus</em>: <figure><img></figure><figure><img></figure><figure><img></figure><figure><img></figure></p></span></li></ul><figure><img></figure></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90012-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79292612","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}

{"title":"Biochimica et biophysica acta,","authors":"","doi":"10.1016/0926-6593(66)90029-4","DOIUrl":"https://doi.org/10.1016/0926-6593(66)90029-4","url":null,"abstract":"","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90029-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137408309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Purification and properties of sulfite: Cytochrome c oxido-reductase from Thiobacillus novellus","authors":"A. Michael Charles ,&nbsp;Isamu Suzuki","doi":"10.1016/0926-6593(66)90013-0","DOIUrl":"10.1016/0926-6593(66)90013-0","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. Sulfite oxidase (sulfite: cytochrome <span><math><mtext>c</mtext></math></span> oxidoreductase) was purified from <em>Thiobacillus novellus</em> and the properties were studied.</p></span></li><li><span>2.</span><span><p>2. Sulfite oxidase did not require AMP for sulfite oxidation and was distinct from adenosine phosphosulfate reductase of <em>Thiobacillus thioparus</em>.</p></span></li><li><span>3.</span><span><p>3. The enzyme reduced either ferricyanide or cytochrome <span><math><mtext>c</mtext></math></span> with sulfite stoichiometrically, reducing 2 moles of the electron acceptor for every mole of sulfite.</p></span></li><li><span>4.</span><span><p>4. the pH optimum of enzyme was around 8 with potassium phosphate buffers.</p></span></li><li><span>5.</span><span><p>5. No cofactor requirements were demonstrated for the enzyme activity.</p></span></li><li><span>6.</span><span><p>6. The enzyme was specific for sulfite as substrate. Thiosulfate, cysteine, GSH, NANO₂ and NH₂OH did not replace sulfite.</p></span></li><li><span>7.</span><span><p>7. The <span><math><mtext>K</mtext><msub><mi></mi><mn>m</mn></msub></math></span> for sulfite at pH 8.0 was determined as 4·10⁻⁵ M and 2·10⁻⁵ M with cytochrome <span><math><mtext>c</mtext></math></span> and ferricyanide as electron acceptors, respectively. At pH 6.5 the <span><math><mtext>K</mtext><msub><mi></mi><mn>m</mn></msub></math></span> for sulfite was 2·10⁻⁶ M with cytochrome <span><math><mtext>c</mtext></math></span>.</p></span></li><li><span>8.</span><span><p>8. Various salts and buffers inhibited the enzyme activity. With NaCl the inhibition was found to be competitive with respect to sulfite. The <span><math><mtext>K</mtext><msub><mi></mi><mn>i</mn></msub></math></span> was calculated as 4.5· 10⁻³ M.</p></span></li><li><span>9.</span><span><p>9. The enzymes was strongly inhibited by various sulfhydryl inhibitors inlcuding <span><math><mtext>p-</mtext><mtext>hydroxymercuribenzoate</mtext></math></span> and <span><math><mtext>N-</mtext><mtext>ethylmaleimide</mtext></math></span>. The inhibition by <span><math><mtext>p-</mtext><mtext>hydroxymercuribenzoate</mtext></math></span> was completely reversed by GSH.</p></span></li><li><span>10.</span><span><p>10. Methylene blue, NAD⁺, NADP⁺ and O₂ did not replace Fe(CN)₆³⁻ or cytochrome <span><math><mtext>c</mtext></math></span> as electron acceptor for sulfite oxidase. <em>T. novellus</em> cytochrome <span><math><mtext>c</mtext></math></span> was reduced by the enzyme and sulfite and subsequently oxidized by <em>T. novellus</em> cytochrome oxidase.</p></span></li><li><span>11.</span><span><p>11. Oxidative phosphorylation coupled to sulfite oxidation with a low P/O ratio was demonstrated in cell-free extracts of <em>T. novellus</em>.</p></span></li><li><span>12.</span><span><p>12. It is conc","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90013-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91364768","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}

{"title":"Iodination of ribonuclease in the presence of cytidine 3′-phosphate","authors":"Michael E. Friedman,&nbsp;Harold A. Scheraga","doi":"10.1016/0926-6593(66)90020-8","DOIUrl":"10.1016/0926-6593(66)90020-8","url":null,"abstract":"","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90020-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90134554","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}

{"title":"Aromatic metabolism in plants III. Quinate dehydrogenase from mung bean cell suspension cultures","authors":"Oluf L. Gamborg","doi":"10.1016/0926-6593(66)90009-9","DOIUrl":"10.1016/0926-6593(66)90009-9","url":null,"abstract":"<div><p>Quinate dehydrogenase (Quinate: NAD⁺ oxidoreductase, EC 1.1.1.24) was extracted from liquid suspension cultures of mung bean (<em>Phaseolus aureus</em> Roxb.).</p><p>The cells were disrupted by ultrasonic energy, and the enzyme purified by precipitation with ammonium sulfate and elution from columns of Sephadex G-50 and hydroxylapatite. The enzyme was unstable but the activity could be maintained for several weeks after purification of hydroxylapatite when stored at pH 7.5 and at −20°.</p><p>The optimum pH for activity was 9.6. The enzyme was specific for NAD⁺. Addition of phenylpyruvate, phenylalanine, cinnamate, or shikimate had no effect on its activity. The enzyme was inhibited by sulfhydryl inhibitors, borate, molybdate, and dehydroquinate. 4-Hydroxybenzoic acid and 3-hydroxybenzoic acid were competitive inhibitors.</p><p>The cells also contained 5-dehydroquinate dehydratase (EC 4.2.1.10) and shikimate dehydrogenase (EC 1.1.1.25) and thus contained all the enzymes necessary for the interconversion of quinate and shikimate. Quinate dehydrogenase resembled shikimate dehydrogenase in its pH optimum, inhibition by borate and by the substituted benzoic acids.</p></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90009-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89340208","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}

{"title":"Insect extramitochondrial glycerophosphate dehydrogenase II. Enzymic properties and amino acid composition of the enzyme from honeybee (Apis mellifera) thoraces","authors":"Ronald W. Brosemer,&nbsp;Ronald R. Marquardt","doi":"10.1016/0926-6593(66)90007-5","DOIUrl":"10.1016/0926-6593(66)90007-5","url":null,"abstract":"<div><p>Several enzymic properties of crystalline honeybee (<em>Apis mellifera</em>) thoracic glycerophosphate dehydrogenase (<span>L</span>-glycerol-3-phosphate:DPN⁺ oxidoreductase, EC 1.1.1.8) were determined. The apparent Michaelis constant for dihydroxyacetone phosphate is 0.33 mM; there is no increase in activity with substrate concn. above 0.5 mM.</p><p>The bee enzyme has a broad pH optimum around pH 6.6, while the rabbits-muscle enzyme has a sharp optimum at pH 7.7. The bee enzyme is stable for 15 min at 21° from pH 4.8 to 9.9.</p><p>The temperature coefficient, <span><math><mtext>Q</mtext><msub><mi></mi><mn>10</mn></msub></math></span>, for the bee enzyme is 1.7 in the range from 21° 36°. The enzyme is stable for 5 min at 55° and completely inactivated at 61°. The bee enzyme shows the same relative reactivity with 2 DPN⁺ analogues as does the rabbit enzyme. The bee enzyme is inhibited by a low concentration of <span><math><mtext>p-</mtext><mtext>mercuribenzoate</mtext></math></span> (PCMB), is less sensitive to <span><math><mtext>N-</mtext><mtext>ethylmaleimide</mtext></math></span>, and is not inhibited by 1 mM iodoacetate. Glutathione does not activate the enzyme.</p><p>The amino acid composition of the bee enzyme is quite different from the previously reported composition of the rabbits-muscle enzyme. The minimum molecular weight of the bee enzyme based on 1 tryptophan residue is 32 700. Since the molecular weight determined on a Sephadex G-200 column is around 67 000, the amino acid composition indicates a mol. wt. of 65 400.</p></div>","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90007-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72932893","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}

{"title":"Guanosine diphosphate D-mannose pyrophosphorylase from Gleditschia macracantha","authors":"Luis Jimenez de Asua,&nbsp;Hector Carminatti,&nbsp;Susana Passeron","doi":"10.1016/0926-6593(66)90022-1","DOIUrl":"10.1016/0926-6593(66)90022-1","url":null,"abstract":"","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90022-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74881699","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}

{"title":"Modification of the esteratic activity of acetylcholinesterase by alkylation with 1,1-dimethyl-2-phenylaziridinium ion","authors":"Jocelyn E. Purdie,&nbsp;Robert A. McIvor","doi":"10.1016/0926-6593(66)90025-7","DOIUrl":"10.1016/0926-6593(66)90025-7","url":null,"abstract":"","PeriodicalId":100160,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology and Biological Oxidation","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1966-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6593(66)90025-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75094054","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}