Journal of applied biochemistry最新文献_第10页

Detection and determination of cysteamine at the nanomole level. 纳米级半胱胺的检测与测定。

Journal of applied biochemistry Pub Date : 1983-08-01

G Ricci, M Nardini, R Chiaraluce, S Duprè, D Cavallini

引用次数: 0

Polymer cellulose sheets immobilizing antibody by radiation polymerization. 高分子纤维素片辐射聚合固定化抗体。

Journal of applied biochemistry Pub Date : 1983-08-01

M Kumakura, I Kaetsu

引用次数: 0

Isolation and properties of beta-galactosidase of a strain of Lactobacillus helveticus isolated from natural whey starter. 从天然乳清发酵剂中分离的一株helveticus乳杆菌的β -半乳糖苷酶的分离及性质。

Journal of applied biochemistry Pub Date : 1983-08-01

M E de Macías, M C Manca de Nadra, A M Strasser de Saad, A A Pesce de Ruiz Holgado, G Oliver

{"title":"Isolation and properties of beta-galactosidase of a strain of Lactobacillus helveticus isolated from natural whey starter.","authors":"M E de Macías, M C Manca de Nadra, A M Strasser de Saad, A A Pesce de Ruiz Holgado, G Oliver","doi":"","DOIUrl":"","url":null,"abstract":"beta-Galactosidase has been isolated from Lactobacillus helveticus of a strain isolated from natural starters for the manufacture of Argentine hard cheeses and its properties have been studied. The enzyme was purified 14-fold (by chromatography on DEAE-cellulose and Sepharose 6B-DEAE-cellulose columns and by affinity chromatography in agarose-p-aminophenyl-beta-D-thiogalactoside). The purified extract exhibited a single band following polyacrylamide gel electrophoresis. Maximum enzymatic activity was observed at 42 degrees C and pH 6.5 in 50 mM phosphate buffer. At pH values substantially different from the optimum, a positive cooperativity between substrate molecules was observed. The Km's for o-nitrophenylgalactoside (ONPG) and ONPG + 10 mM of lactose were 4.46 X 10(-5) and 8.9 X 10(-5) M, respectively. Glucose, galactose, galactose 6-phosphate, and lactate acted as noncompetitive inhibitors; MgCl2 protected the enzyme from thermal denaturation. The activation energy of enzymatic hydrolysis of ONPG was 11,400 cal/mol. The Mr was estimated to be 250,000. It is an oligomeric enzyme made of 4 subunits of Mr 65,000.","PeriodicalId":14978,"journal":{"name":"Journal of applied biochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17493382","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

Chromatographic preparation and in vitro properties of albumin from human plasma. 人血浆白蛋白的色谱制备及体外特性研究。

Journal of applied biochemistry Pub Date : 1983-08-01

J H Berglöf, S Eriksson, J M Curling

引用次数: 0

Fungal glucoamylases. 真菌葡糖淀粉酶。

Journal of applied biochemistry Pub Date : 1983-08-01

P Manjunath, B C Shenoy, M R Raghavendra Rao

{"title":"Fungal glucoamylases.","authors":"P Manjunath, B C Shenoy, M R Raghavendra Rao","doi":"","DOIUrl":"","url":null,"abstract":"Glucoamylase (alpha-1,4-glucan glucohydrolase, EC 3.2.1.3) from fungal sources is one of the microbial glycoproteins that has received considerable attention particularly because it is used in the commercial production of dextrose. Several investigators have isolated glucoamylase from various fungal sources. In many instances the presence of more than one form of enzyme is common. The enzymes from most sources have pH optima between 4 and 5 and exhibit maximum activity between 40 and 60 degrees C. The enzyme does not require any cofactors for activity or for stability. The enzyme has an Mr between 48,000 and 80,000 and usually has no subunit structure. The amino acid composition of multiple forms of glucoamylases differ in general, but all of them are glycoproteins. The carbohydrate content of the enzyme ranges from 3 to 30% containing mainly mannose, but glucose, galactose, and in some instances glucosamine and xylose are also present. In the enzyme from Aspergillus the carbohydrate structures are present as mono-, di-, tri-, and tetrasaccharide units linked O-glycosidically through mannose to the hydroxyl groups of serine and threonine. In the enzyme from Rhizopus part of the carbohydrate is present as disaccharide (Man-Man-) units linked O-glycosidically and the remainder is present as large heterosaccharide structures attached by N-glycosidic linkages involving aspargine and glucosamine. Carbohydrate moieties seem to have no influence on the enzyme activity or antigenicity but appear to stabilize the enzyme by preserving the three-dimensional structure.","PeriodicalId":14978,"journal":{"name":"Journal of applied biochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17493380","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

Enzyme therapy: II. Effect of covalent attachment of polyethylene glycol on biochemical parameters and immunological determinants of beta-glucosidase and alpha-galactosidase. 酶治疗:聚乙二醇共价附着对-葡萄糖苷酶和-半乳糖糖苷酶生化参数和免疫学决定因素的影响。

Journal of applied biochemistry Pub Date : 1983-08-01

K J Wieder, F F Davis

{"title":"Enzyme therapy: II. Effect of covalent attachment of polyethylene glycol on biochemical parameters and immunological determinants of beta-glucosidase and alpha-galactosidase.","authors":"K J Wieder, F F Davis","doi":"","DOIUrl":"","url":null,"abstract":"The covalent attachment of polyethylene glycol (PEG) to beta-glucosidase from sweet almonds and alpha-galactosidase from green coffee beans results in alterations of their catalytic properties and masking of specific determinant sites on the enzymes. Both enzymes have increased Km and decreased Vmax values against their respective p-nitrophenyl substrate analogs after PEG attachment. When PEG is attached to 30% of alpha-galactosidase epsilon-amino groups, 12% activity remains against ceramide trihexoside, while its ability to convert type B erythrocytes to type H specificity is lost. However, it still is able to cleave terminal galactose residues from human saliva blood group substance B. PEG-beta-glucosidase (38%) did not elicit the production of complement-fixing antibodies, nor did it react with antibodies produced against the native enzyme. Antibody and lectin-specific binding were lost from both modified enzymes (PEG-beta-glucosidase and PEG-alpha-galactosidase). After conjugation with PEG, beta-glucosidase lost its ability to bind to concanavalin A-Sepharose. Antibodies directed against native alpha-galactosidase blocked its enzyme activity, but lost their ability to inhibit activity in progressively higher modified preparations of the enzyme. Antisera against PEG-alpha-galactosidase (53%) did not inhibit enzyme activity in any alpha-galactosidase or PEG-alpha-galactosidase preparation. These results indicate that PEG tends to cover lectin-specific carbohydrate moieties and antigenic determinants and that these sites probably remain cryptic during in vivo processing of PEG-enzymes.","PeriodicalId":14978,"journal":{"name":"Journal of applied biochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17271578","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

Purification and characterization of glutathione synthetase from Escherichia coli B. 大肠杆菌B谷胱甘肽合成酶的纯化及特性研究。

Journal of applied biochemistry Pub Date : 1983-06-01

H Gushima, T Miya, K Murata, A Kimura

引用次数: 0

Firefly and bacterial luminescence: basic science and applications. 萤火虫与细菌的发光:基础科学与应用。

Journal of applied biochemistry Pub Date : 1983-06-01

W D McElroy, M A DeLuca

{"title":"Firefly and bacterial luminescence: basic science and applications.","authors":"W D McElroy, M A DeLuca","doi":"","DOIUrl":"","url":null,"abstract":"The basic chemistry of the reactions leading to light emission in the firefly and in bacteria are briefly reviewed. With excess firefly reagents, the light intensity is proportional to the ATP concentration. For this reason, the reagents have been used for ATP determination in a number of important biological systems. A number of such applications are reviewed. With excess bacterial reagents, the light intensity is directly proportional to the reduced pyridine nucleotide concentration (NADH or NADPH). The applications of this system for studying reactions involving dehydrogenases using NAD or NADP as electron acceptors are presented. Many assays have now been developed using enzymes immobilized on Sepharose. The advantages of using the immobilized enzymes are greater stability of the immobilized enzymes over the soluble forms; increased sensitivity of detection relative to the soluble forms, and reusability of the immobilized enzymes. A comparison of the immobilized bioluminescent assay for 7 alpha-hydroxysteroid with gas-liquid chromatography and radioimmunoassay is presented. Coimmobilized enzymes can be packed in a flow cell and used in an automated instrument with good reproducibility. It is likely that future developments of bioluminescent assays for ATP or NAD(P)H will be with immobilized enzymes using an automated instrument.","PeriodicalId":14978,"journal":{"name":"Journal of applied biochemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1983-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17735931","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 biochemical adventure--the hunt for vitamin D. 一场生化冒险——寻找维生素D。

Journal of applied biochemistry Pub Date : 1983-06-01

T H Jukes

引用次数: 0

Encapsulation of exogenous agents in erythrocytes and the circulating survival of carrier erythrocytes. 外源性药物在红细胞中的包封和载体红细胞的循环存活。

Journal of applied biochemistry Pub Date : 1983-06-01

J R DeLoach

引用次数: 0