Biochimica et Biophysica Acta (BBA) - Enzymology最新文献_第10页

Purification and properties of a polyadenylate polymerase from Artemia dormant embryos 青蒿休眠胚聚腺苷酸聚合酶的纯化及性质研究

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90083-8

Leandro Sastre, Jesús Sebastián

{"title":"Purification and properties of a polyadenylate polymerase from Artemia dormant embryos","authors":"Leandro Sastre, Jesús Sebastián","doi":"10.1016/0005-2744(81)90083-8","DOIUrl":"10.1016/0005-2744(81)90083-8","url":null,"abstract":"<div>Soluble extracts from encysted dormant embryos of Artemia contain a poly(A) polymerase activity which has been partially purified and characterized. The enzyme requires manganese, an RNA primer and ATP for maximal activity. The Km for ATP is 0.04 mM and the enzyme is inhibited by concentrations higher than 0.5 mM ATP. dATP replaces ATP with a 15% efficiency. The Km for dATP is 0.06 mM. Natural RNAs, poly(A) and poly(AG) are the best RNA primers among several homopolymers and copolymers tested. The poly(A) polymerase does not show any specificity for the nucleotide in the 3′ end of the RNA primer. The product of the reaction is a polyadenylic acid chain covalently bound to the RNA primer molecule. The length of the poly(A) chain is about ten nucleotides, but this length is dependent on the incubation time and the RNA primer concentration. The molecular weight of the enzyme is 70 000 and its isoelectric point is 6.0. The existence of an active poly(A) polymerase in dormant embryos of Artemia, likely with a cytoplasmic localization, suggests a role for this enzyme in the processing and activation of the stored mRNAs after resumption of development.</div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"661 1","pages":"Pages 54-62"},"PeriodicalIF":0.0,"publicationDate":"1981-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90083-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74945877","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

Identification and partial characterization of two enzyme forms of iduronate sulfatase from human placenta 人胎盘中两种酶的鉴定和部分表征

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90088-7

Paola Di Natale, Luisa Ronsisvalle

引用次数: 12

Specificity and other properties of an alcohol dehydrogenase purified from Comamonas terrigena 从terrigena单胞菌中纯化的乙醇脱氢酶的特异性和其他性质

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90085-1

Carol H. Barrett, Kenneth S. Dodgson, Graham F. White

{"title":"Specificity and other properties of an alcohol dehydrogenase purified from Comamonas terrigena","authors":"Carol H. Barrett, Kenneth S. Dodgson, Graham F. White","doi":"10.1016/0005-2744(81)90085-1","DOIUrl":"10.1016/0005-2744(81)90085-1","url":null,"abstract":"<div>An NAD-dependent alcohol dehydrogenase (alcohol : NAD+ oxidoreductase, EC 1.1.1.1) active towards l-octan-2-ol but not towards the corresponding d-isomer was purified to homogeneity from the soil bacterium Comamonas terrigena. The enzyme is a tetramer (molecular weight 125 000–141 000) and is most active at pH 8.5–9.9. Preferred alcohol substrates are l-alkan-2-ols, activity towards which was inhibited by EDTA, 1,10-phenanthroline and 2,2′-bipyridine. The enzyme exhibits much weaker activity towards primary alcohols, symmetrical secondary alcohols and asymmetric secondary alcohols in which the hydroxyl moiety is located at positions other than C-2, and little or no activity towards d-alkan-2-ols. For l-alkan-2-ols, symmetrical secondary alcohols and primary alcohols, log Km values decrease linearly with increase in the number of carbon atoms in the alkyl chain. A plot of standard free-energy of binding (ΔG0′) of substrates against the number of carbon atoms in the alkyl chain (primary alcohols) or the longer of the two portions of the alkyl chain (secondary alcohols) gives a single straight-line relationship, suggesting that hydrophobic interactions make an important contribution to substrate binding. The observed specificity was interpreted in terms of a model in which secondary alcohols interact with the enzyme through the hydrogen and hydroxyl group that participate in NAD+ reduction, and one of the two alkyl segments. The size of the unbound alkyl segment markedly affects V, the optimum being a single methyl unit. This specificity was correlated with that of the CS2 secondary alkylsulphohydrolase that catalyses the production of l-alkan-2-ols from d-alkan-2-yl sulphate surfactants.</div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"661 1","pages":"Pages 74-86"},"PeriodicalIF":0.0,"publicationDate":"1981-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90085-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78009548","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: 15

Interaction of AMP deaminase with RNA AMP脱氨酶与RNA的相互作用

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90096-6

Nobuaki Ogasawara, Haruko Goto, Yasukazu Yamada

{"title":"Interaction of AMP deaminase with RNA","authors":"Nobuaki Ogasawara, Haruko Goto, Yasukazu Yamada","doi":"10.1016/0005-2744(81)90096-6","DOIUrl":"10.1016/0005-2744(81)90096-6","url":null,"abstract":"<div>tRNA, 18 S and 28 S ribosomal RNAs were found to activate muscle AMP deaminase (AMP aminohydrolase, EC 3.5.4.6) but inhibit liver and heart AMP deaminases. The macromolecular structures are essential for modulation of enzyme activity, since the effects of RNA disappeared after RNAase treatment. Sucrose density centrifugation experiments clearly demonstrated the binding of purified muscle AMP deaminase to tRNA, 18 S and 28 S RNAs. The binding is reversible and responsive to alterations of pH and KCl concentration. The binding was stable at pH 5.1–7.0 in 0.1 M KCl, but most of the enzyme dissociated at pH 7.5. KCl below 0.1 M concentration had no effect on dissociation of enzyme-RNA complex, but in 0.15 M KCl the complex was partially dissociated and in 0.2 M KCl most of the enzyme was released. Various nucleotides were also effective in dissociation of the enzyme from complex. The binding is saturable and the maximum number of muscle AMP deaminase molecules bound per mol 28 S RNA was calculated to be approx. 30. Liver and heart AMP deaminases were also found to interact with RNA.</div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"661 1","pages":"Pages 164-169"},"PeriodicalIF":0.0,"publicationDate":"1981-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90096-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17235678","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: 1

Phosphofructokinases from Lactobacteriaceae 乳杆菌科的磷酸果糖激酶

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90095-4

Wolfgang A. Simon, Hans Werner Hofer

引用次数: 5

Characterization of immobilized β-Glucuronidase in aqueous and mixed solvent systems 固定化β-葡萄糖醛酸酶在水溶液和混合溶剂体系中的表征

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-09-15 DOI: 10.1016/0005-2744(81)90087-5

Larry D. Bowers, Peter R. Johnson

{"title":"Characterization of immobilized β-Glucuronidase in aqueous and mixed solvent systems","authors":"Larry D. Bowers, Peter R. Johnson","doi":"10.1016/0005-2744(81)90087-5","DOIUrl":"10.1016/0005-2744(81)90087-5","url":null,"abstract":"<div>β-Glucuronidase (β-d-glucuronide glucuronosohydrolase, EC 3.2.1.31) was covalently attached to alkylamine-controlled pore glass via a glutaraldehyde immobilization scheme. The activity of this immobilized β-glucuronidase was studied with respect to several kinetic parameters in comparison with the behavior of the soluble enzyme. Km values for p-nitrophenyl glucuronide, estriol-3-glucuronide, and estriol-16β-glucuronide were determined. For each substrate the Km was essentially the same, 0.2 mM, and this value did not change when the enzyme was immobilized. The soluble and immobilized enzyme both displayed a relatively broad pH maximum centered at pH 6.8 for all substrates. Several organic-aqueous mixtures including methanol, ethanol, acetonitrile and ethylene glycol were tested, and their effects on the activity of immobilized β-glucuronidase were similar to those found for the soluble enzyme. Long-term (1 year) storage stability tests of the immobilized enzyme were carried out. The immobilized enzyme retained 40% of its initial activity after 1 year and was very robust towards most of the organic solvents tested.</div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"661 1","pages":"Pages 100-105"},"PeriodicalIF":0.0,"publicationDate":"1981-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90087-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83198341","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: 33

Thermostable, ammonium-activated malic enzyme of Clostridium thermocellum 热细胞梭状芽胞杆菌的耐热、氨活化的苹果酸酶

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-08-13 DOI: 10.1016/0005-2744(81)90167-4

R. Lamed , J.G. Zeikus

{"title":"Thermostable, ammonium-activated malic enzyme of Clostridium thermocellum","authors":"R. Lamed , J.G. Zeikus","doi":"10.1016/0005-2744(81)90167-4","DOIUrl":"10.1016/0005-2744(81)90167-4","url":null,"abstract":"<div>‘Malic’ enzyme (l-malate:NADP+ oxidoreductase (oxaloacetate-decarboxylating, EC 1.1.1.40) was purified from Clostridium thermocellum by DEAE-cellulose, agarose-NADP and Sephadex G-200 column chromatography. The 117-fold purified ‘malic’ enzyme displayed a maximum activity of 135 units/mg at 40°C and represented 0.8% of the total cell protein. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis analysis of the protein suggested 90% purity and an approximate tetrameric subunit molecular weight of 40 000. The enzyme absolutely required both bivalent and monovalent cations for catalysis. Mn2+ and NH4+ were the most effective cationic activators examined. Increasing NH4+ concentration increased both enzyme activity and affinity toward l-malate. The apparent Km for l-malate was 3 · 10−4 M at 0.4 mM NH4Cl. Enzyme activity increased linearly when temperature was raised between 22–60°C and a Q10 of 2.1 was calculated from an Arrhenius plot. The enzyme was stable to heating at 60°C but was denatured at higher temperatures. The enzyme half-life was 10 min at 72°C. The enzyme displayed a broad pH optimum (7.2–8.2 for Tris-HCl buffer) but was inactivated by p-chloromercuribenzoate. The high thermal stability, low apparent molecular weight and NH4+ activation are properties not common to all previously described ‘malic’ enzymes.</div>","PeriodicalId":100159,"journal":{"name":"Biochimica et Biophysica Acta (BBA) - Enzymology","volume":"660 2","pages":"Pages 251-255"},"PeriodicalIF":0.0,"publicationDate":"1981-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0005-2744(81)90167-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18297145","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: 50

A sepharose derivative coupled with a leupeptin-like peptide aldehyde, glycylglycyl-l-argininal, and its use as an affinity adsorbent for trypsin 一种与胰蛋白酶样肽醛、甘酰甘氨酸精氨酸偶联的sepharose衍生物，其用作胰蛋白酶的亲和吸附剂

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-08-13 DOI: 10.1016/0005-2744(81)90168-6

Makoto Nishikata , Ken-Ichi Kasai , Shin-Ichi Ishii

引用次数: 8

Isolation of two endo-β-N-acetylglucosaminidases from fig latex 无花果胶乳中两个内端-β- n -乙酰氨基葡萄糖酶的分离

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-08-13 DOI: 10.1016/0005-2744(81)90171-6

Su-Chen Li, Makio Asakawa, Yoshio Hirabayashi, Yu-Teh Li

引用次数: 11

Cleavage of human serum immunoglobulin G by an immobilized pepsin preparation 固定化胃蛋白酶制备人血清免疫球蛋白G的裂解

Biochimica et Biophysica Acta (BBA) - Enzymology Pub Date : 1981-08-13 DOI: 10.1016/0005-2744(81)90158-3

Tsugikazu Tomono, Tohru Suzuki, Eiichi Tokunaga

引用次数: 22