{"title":"Investigation of the active sites of lysozyme. Carboxymethylation of the imidazole group of histidine and of the ϵ-aminogroup of lysine","authors":"N.A. Kravchenko, G.V. Kléopina, E.D. Kaverzneva","doi":"10.1016/0926-6569(64)90205-6","DOIUrl":"10.1016/0926-6569(64)90205-6","url":null,"abstract":"","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 412-414"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90205-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802148","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":"Studies on succinate dehydrogenase","authors":"D.V. Dervartanian, C. Veeger","doi":"10.1016/0926-6569(64)90182-8","DOIUrl":"10.1016/0926-6569(64)90182-8","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. Succinate dehydrogenase (succinate: (acceptor) oxidoreductase, EC 1.3.99.1) reacts immediately with competitive inhibitors to form spectrally detectable enzyme-inhibitor complexes, which are converted to succinate-reduced enzyme on the subsequent addition of succinate.</p></span></li><li><span>2.</span><span><p>2. The enzyme-inhibitor complexes formed with malonate, fumarate, maleate and methylene succinate differ from that with oxaloacetate in spectral characteristics, the latter showing a wide, diffuse band from 500 to 750 mμ.</p></span></li><li><span>3.</span><span><p>3. Pyrophosphate, a strong competitive inhibitor of succinate dehydrogenase, but which is not in any obvious way structurally related to succinate, has no effect on the spectrum.</p></span></li><li><span>4.</span><span><p>4. Dissociation constants of the enzyme-inhibitor complexes determined by spectral titration are in good agreement with kinetically determined inhibitor constants.</p></span></li><li><span>5.</span><span><p>5. The changes in spectrum associated with the formation of the enzyme-inhibitor complexes are explainable in terms of changes in polarity near the flavin prosthetic group and by the formation of charge-transfer complexes between the electron-donating inhibitor and the electron-accepting enzyme.</p></span></li><li><span>6.</span><span><p>6. The apparent incomplete reoxidation by fumarate of dithionite-reduced enzyme, reported by previous workers, can be explained by the formation of the complex between oxidized enzyme and fumarate.</p></span></li></ul></div>","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 233-247"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90182-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83751112","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":"Fractionation of proteolytic enzymes from sisal (Agave sisalanus) on deae-cellulose","authors":"K.F. Tipton","doi":"10.1016/0926-6569(64)90191-9","DOIUrl":"10.1016/0926-6569(64)90191-9","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. Crude sisal extract has been fractionated into seven protein components by chromatography on DEAE-cellulose.</p></span></li><li><span>2.</span><span><p>2. Each component was shown to be essentially homogeneous on rechromatography on DEAE-cellulose and on gel filtration on Sephadex G 100.</p></span></li><li><span>3.</span><span><p>3. Five of the components were shown to have proteolytic activity toward casein and four had amidase activity toward α-benzoyl-<span>l</span>-arginine amide.</p></span></li><li><span>4.</span><span><p>4. Four of the active components were found to be inhibited by metal binding agents and di-isopropylphosphorofluoridate.</p></span></li><li><span>5.</span><span><p>5. None of the active components appeared to depend on a sulphydryl group for activity.</p></span></li><li><span>6.</span><span><p>6. The components differed in their specific activities, pH optima, and molelcular weights as indicated by gel filtration on Sephadex G 100.</p></span></li></ul></div>","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 334-340"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90191-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23803516","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":"Biosynthesis of valine and isoleucine in plants II. Dihydroxyacid dehydratase from Phaseolus radiatus","authors":"T. Satyanarayana, A.N. Radhakrishnan","doi":"10.1016/0926-6569(64)90195-6","DOIUrl":"10.1016/0926-6569(64)90195-6","url":null,"abstract":"<div><p></p><ul><li><span>1.</span><span><p>1. An enzyme catalysing the conversion of α,β-dihydroxyisovalerate and α,β-dihydroxy-β-methylvalerate to α-ketoisovalerate and α-keto-β-methylvalerate has been partially purified from green gram (<em>Phaseolus radiatus</em>), and its characteristics studied.</p></span></li><li><span>2.</span><span><p>2. A natural inhibitor, heat stable and inorganic in nature, was observed in the crude extracts.</p></span></li><li><span>3.</span><span><p>3. The observed <em>K</em><sub>m</sub> values for α-β-dihydroxyisovalerate and α,β-dihydroxy-β-methylvalerate were 2.4 · 10<sup>−3</sup> M and 9 · 10<sup>−4</sup> M, respectively.</p></span></li><li><span>4.</span><span><p>4. The enzyme required the presence of a divalent metal ion (Mg<sup>2+</sup>, Mn<sup>2+</sup> or Fe<sup>2+</sup>) for maximal activity. Heavy metals like Ag<sup>+</sup> and Hg<sup>2+</sup> were inhibitory.</p></span></li><li><span>5.</span><span><p>5. The optimal activity was around pH 8.0 and the optimum temperature at 52°. The activation energy is found to be 12 600 cal/mole.</p></span></li><li><span>6.</span><span><p>6. The enzyme was inhibited by <em>p</em>-hydroxymercuribenzoate, <em>N</em>-ethylmaleimide and sulphydryl compounds like cysteine, glutathione, 2-mercaptoethanol and 2,3-dimercaptopropanol. The inhibition by <em>p</em>-hydroxymercuribenzoate could not be reversed by any of the sulfhydryl compounds tested.</p></span></li></ul></div>","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 367-377"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90195-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802139","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}
Charles J. Epstein, Margaret M. Carter, Robert F. Goldberger
{"title":"Reversible denaturation of rabbit-muscle lactate dehydrogenase","authors":"Charles J. Epstein, Margaret M. Carter, Robert F. Goldberger","doi":"10.1016/0926-6569(64)90198-1","DOIUrl":"10.1016/0926-6569(64)90198-1","url":null,"abstract":"","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 391-394"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90198-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802142","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":"The hydroxylation of proline by horseradish peroxidase","authors":"Cecil C. Yip","doi":"10.1016/0926-6569(64)90199-3","DOIUrl":"10.1016/0926-6569(64)90199-3","url":null,"abstract":"","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 395-396"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90199-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802143","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":"Carbon monoxide-combining substances in rat adrenal","authors":"Boyd W. Harding, Siu Ha Wong, Don H. Nelson","doi":"10.1016/0926-6569(64)90206-8","DOIUrl":"10.1016/0926-6569(64)90206-8","url":null,"abstract":"","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 415-417"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90206-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802149","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":"Electron-transport enzymes of calf thyroid","authors":"L.J. Degroot, A.D. Dunn","doi":"10.1016/0926-6569(64)90180-4","DOIUrl":"10.1016/0926-6569(64)90180-4","url":null,"abstract":"<div><p>Electron transport enzymes, RNA, DNA, and iodinating activity have been assayed in subcellular fractions derived from calf tissue.</p><p>About 0.1 μequiv DPNH is oxidized per min by mitochondria prepared from 1 g thyroid in 0.25 M sucrose and assayed at 25°. Cytochrome <em>c</em> reductase system and cytochrome oxidase (EC 1.9.3.1) activities, confined largely to the “mitochondrial” fractions, are more than 10 times greater. DPNH oxidase system is antimycin A-sensitive; cytochrome <em>c</em> reductase system is antimycin A-insensitive. Reduced pyridine nucleotide-dichlorophenol-indophenol reductase (“DT diaphorase”), TPN+-specific isocitrate dehydrogenase (EC 1.1.1.42), and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) are present in the soluble portion in cell and have activities comparable to cytochrome <em>c</em> reductase system and cytochrome oxidase. There is ample basis for formation of large amounts of TPNH within the cell, and its rate of oxidation appears to be low.</p><p>RNA was distributed throughout all cell fractions without marked concentration in “microsomes”, and almost 70% was in the cell supernatant.</p><p>Iodinating activity was most intense in fractions that may be classified as heavy microsomes, and its distribution did not coincide with the distribution of cytochrome <em>c</em> reductase system or cytochrome oxidase.</p><p>Electron-transport enzymes, iodinating activity, and nucleic acid content varied in parallel following physiologic alterations in rat-thyroid function.</p></div>","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 205-222"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90180-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"23802400","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":"Thyroid “DT diaphorase”","authors":"L.J. DeGroot, Ronald Dechene, J. Thompson","doi":"10.1016/0926-6569(64)90181-6","DOIUrl":"10.1016/0926-6569(64)90181-6","url":null,"abstract":"<div><p>The enzyme “DT diaphorase”, which mediates transfer of electrons from TPNH or DPNH to dichlorophenol-indophenol is abundant in the thyroid. In common with the enzyme described by Ernster and coworkers<sup>1</sup> in liver, the enzyme is largely present in the soluble portion of the cell, and is inhibited by bishydroxycoumarin, but not by antimycin A. Addition of FAD markedly augments activity.</p><p>The enzyme appears to play little role in oxidative metabolism and could not be related to iodination of tyrosine by thyroid cell particles or a soluble iodinating enzyme derived from the particles.</p></div>","PeriodicalId":100170,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Specialized Section on Enzymological Subjects","volume":"92 2","pages":"Pages 223-232"},"PeriodicalIF":0.0,"publicationDate":"1964-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0926-6569(64)90181-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90616538","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}