Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468903

E M Bailyes, D L Bennett, J C Hutton

引用次数: 34

Adenosine 3':5'-monophosphate-dependent protein kinase from human placenta: characterization of the catalytic subunit. 来自人胎盘的腺苷3':5'-单磷酸依赖蛋白激酶:催化亚基的表征。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468874

A Tamanini, G Berton, G Cabrini

引用次数: 4

Mammalian neural and endocrine pro-protein and pro-hormone convertases belonging to the subtilisin family of serine proteinases. 哺乳动物神经和内分泌前蛋白转化酶和前激素转化酶属于丝氨酸蛋白酶的枯草菌素家族。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468901

N G Seidah, R Day, M Marcinkiewicz, S Benjannet, M Chrétien

{"title":"Mammalian neural and endocrine pro-protein and pro-hormone convertases belonging to the subtilisin family of serine proteinases.","authors":"N G Seidah, R Day, M Marcinkiewicz, S Benjannet, M Chrétien","doi":"10.1159/000468901","DOIUrl":"https://doi.org/10.1159/000468901","url":null,"abstract":"Conversion of pro-hormones and precursor proteins into biologically active peptides and proteins involves the concerted action of a number of convertases and post-translation modification enzymes. The identification of the yeast convertase kexin as a prototype processing enzyme led to the discovery of the mammalian convertase designated furin, PC1 and PC2. Whereas furin is ubiquitously expressed, PC1 and PC2 are found only in endocrine and neural tissues and cell lines. In man and mouse, the genes coding for furin, PC1 and PC2 reside on three different chromosomes. The analysis of the intracellular processing of PC1 and PC2 and the removal of their pro-segment is presented, together with a summary of the cleavage specificity of these enzymes for precursors such as pro-opiomelanocortin (POMC) and human pro-renin. The distinct tissue distribution of PC1 and PC2 and their coregulation with POMC in the pituitary neurointermediate lobe adds credence to their physiological role as convertases involved in the tissue-specific processing of precursor proteins.","PeriodicalId":11933,"journal":{"name":"Enzyme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468901","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13004628","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: 88

Neuroanatomical and functional studies of peptide precursor-processing enzymes. 肽前体加工酶的神经解剖学和功能研究。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468902

W E Cullinan, N C Day, M K Schäfer, R Day, N G Seidah, M Chrétien, H Akil, S J Watson

{"title":"Neuroanatomical and functional studies of peptide precursor-processing enzymes.","authors":"W E Cullinan, N C Day, M K Schäfer, R Day, N G Seidah, M Chrétien, H Akil, S J Watson","doi":"10.1159/000468902","DOIUrl":"https://doi.org/10.1159/000468902","url":null,"abstract":"An overview of in situ hybridization mapping studies comparing the brain distributions of mRNA transcripts encoding the proprotein convertase Furin, PC1 and PC2 in relation to transcripts encoding carboxypeptidase H (CPE) and peptidylglycine alpha-amidating monooxygenase (PAM) is presented. Furin mRNA was detected in both neurons and non-neuronal cells throughout all brain areas. The cellular localization of PC1 and PC2 was primarily neuronal, with PC2 generally more widely distributed, although many regional variations were detected. The detection of specific combinations of the convertases, CPE and PAM in peptide-rich brain regions suggests that specific enzymatic pathways are involved in neuropeptide processing. Results are also described from a series of functional studies on the processing of pro-opiomelanocortin (POMC) in a heterologous neuronal cell line, Neuro-2A, which expresses low levels of PC2 mRNA but no detectable PC1 mRNA. Two contrasting POMC-processing patterns were observed: one where the precursor was processed at a number of cleavage sites to produce several peptides, and another where POMC was processed at a single cleavage site to produce beta E only. If PC2 is responsible for POMC processing in transfected cells, this enzyme may have favored cleavage of the amino terminal-processing site above other sites in the latter type of cell line.","PeriodicalId":11933,"journal":{"name":"Enzyme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468902","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13004629","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: 21

Studies on yeast nucleoside triphosphate-nucleoside diphosphate transphosphorylase (nucleoside diphosphokinase). IV. Steady-state kinetic properties with thymidine nucleotides (including 3'-azido-3'-deoxythymidine analogues). 酵母核苷三磷酸核苷二磷酸转磷酸化酶(核苷二磷酸激酶)的研究。胸腺嘧啶核苷酸(包括3'-叠氮-3'-脱氧胸腺嘧啶类似物)的稳态动力学性质。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468859

S A Kuby, G Fleming, T Alber, D Richardson, H Takenaka, M Hamada

{"title":"Studies on yeast nucleoside triphosphate-nucleoside diphosphate transphosphorylase (nucleoside diphosphokinase). IV. Steady-state kinetic properties with thymidine nucleotides (including 3'-azido-3'-deoxythymidine analogues).","authors":"S A Kuby, G Fleming, T Alber, D Richardson, H Takenaka, M Hamada","doi":"10.1159/000468859","DOIUrl":"https://doi.org/10.1159/000468859","url":null,"abstract":"A study of the steady-state kinetics of the crystalline brewer's yeast (Saccharomyces carlsbergensis) nucleoside diphosphokinase, with the magnesium complexes of the adenine and thymidine nucleotides as reactants, has led to a postulated kinetic mechanism which proceeds through a substituted enzyme. This agrees with the earlier conclusions of Garces and Cleland [Biochemistry 1969; 8:633-640] who characterized a reaction between the magnesium complexes of the adenine and uridine nucleotides. An advantage of using thymidine nucleotides as reactants is that they permit accurate, rapid and continuous assays of the enzymatic activity in coupled-enzymatic tests. Through measurements of the initial velocities and product inhibition studies, the Michaelis constants, maximum velocities, and inhibition constants could be evaluated for the individual substrates. Competitive substrate inhibition was encountered at relatively high substrate concentrations, which also permitted an evaluation of their ability to act as 'dead-end' inhibitors. The Michaelis constants for the 3'-azido-3'-deoxythymidine (AzT) analogues were also evaluated and, although these values were only somewhat higher than those of their natural substrates, the Km's for the adenine nucleotides as paired substrates were lower and the Vmax's were drastically reduced. The pharmacological implications of these observations are touched upon and extrapolated to the cases where therapeutic doses of AzT may be employed.","PeriodicalId":11933,"journal":{"name":"Enzyme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468859","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12832183","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: 3

Role of recombinant DNA in inborn errors of the urea cycle. Short review. 重组DNA在尿素循环先天性错误中的作用。简短的评论。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468869

S D Cederbaum

引用次数: 0

Intramolecular chaperone: the role of the pro-peptide in protein folding. 分子内伴侣:前肽在蛋白质折叠中的作用。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468904

M Inouye

引用次数: 89

Derivatives of plant beta-glucans are hydrolyzed by intestinal lactase-phlorizin hydrolase of mammals. 植物β -葡聚糖衍生物可被哺乳动物肠道乳糖酶-苯丙醇水解酶水解。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468868

J N Freund, F Gossé, F Raul

引用次数: 7

Properties of amphiphilic and hydrophilic forms of alkaline phosphatase from human liver. 人肝脏两亲型和亲水型碱性磷酸酶的性质。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468882

L Kihn, D Rutkowski, T Nakatsui, R A Stinson

引用次数: 5

Hepatic polyamine metabolism in children with Reye's syndrome. 雷氏综合征患儿肝脏多胺代谢的研究。

Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468891

A Mukhopadhyay, D R Deshmukh, A P Sarnaik

{"title":"Hepatic polyamine metabolism in children with Reye's syndrome.","authors":"A Mukhopadhyay, D R Deshmukh, A P Sarnaik","doi":"10.1159/000468891","DOIUrl":"https://doi.org/10.1159/000468891","url":null,"abstract":"Acute mitochondrial insult has been suggested as a primary reason for the clinical, histopathological and biochemical abnormalities seen in Reye's syndrome. However, the etiology of mitochondrial dysfunction has not been identified. Polyamines have been known to alter the mitochondrial structure and function. Influenza infection may cause an increase in ornithine decarboxylase activity and thereby channel ornithine for polyamine biosynthesis, leading to mitochondrial dysfunction in Reye's syndrome. To test this hypothesis, the hepatic concentrations of polyamines, polyamine-metabolizing enzymes and urea cycle enzyme activities in Reye's syndrome patients were determined and compared with patients who died from illnesses other than Reye's syndrome. The hepatic concentration of putrescine, spermidine and spermine were increased in Reye's syndrome patients. The activity of ornithine decarboxylase was elevated but, due to the small number of samples, these values did not reach statistical significance. Ornithine carbamoyltransferase activity was decreased in the liver of Reye's syndrome patients. Our results suggest that increased synthesis of polyamines from ornithine may initiate mitochondrial injury in Reye's syndrome.","PeriodicalId":11933,"journal":{"name":"Enzyme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000468891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12986589","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: 2

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