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Methods compared for determining activity of N-acetyl-beta-D-glucosaminidase in urine without pretreatment of sample: different sensitivity and species effect. 不经样品预处理的尿液n -乙酰- β - d -氨基葡萄糖苷酶活性测定方法比较:不同的灵敏度和种类效应。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468892
K Jung, F Priem, S Klotzek, S Becker, W Henke
{"title":"Methods compared for determining activity of N-acetyl-beta-D-glucosaminidase in urine without pretreatment of sample: different sensitivity and species effect.","authors":"K Jung,&nbsp;F Priem,&nbsp;S Klotzek,&nbsp;S Becker,&nbsp;W Henke","doi":"10.1159/000468892","DOIUrl":"https://doi.org/10.1159/000468892","url":null,"abstract":"<p><p>N-Acetyl-beta-D-glucosaminidase (NAG) activities in the urine of men and rats were measured with methods recommended as procedures without pretreatment of the urine sample. Four different derivatives of NAG were compared for determination: 4-nitrophenyl; 3,3-dichlorophenylsulfonphthaleinyl; 3-cresolsulfonphthaleinyl, and 2-methoxy-4-(2-nitro-vinyl)phenyl. The conventional test using the 4-nitrophenyl derivative showed the highest activities and correlated very well with the other tests. There are method-dependent differences between NAG activities measured in men and rats due to the different Km values and inhibitory effects by urea.</p>","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/10.1159/000468892","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12986590","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: 10
Proteolytic processing and regulation. 蛋白水解加工与调控。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468898
H Neurath
{"title":"Proteolytic processing and regulation.","authors":"H Neurath","doi":"10.1159/000468898","DOIUrl":"https://doi.org/10.1159/000468898","url":null,"abstract":"<p><p>Many proteins, particularly proteolytic enzymes, protein hormones and neuropeptides are synthesized as inactive precursors that undergo posttranslational processing by proteolytic enzymes. The roots of current knowledge go back to the early observations of the activation of zymogens. A major advance followed the discovery of the polypreprotein, pre-pro-opiomelanolcortin and of proinsulin, and the characterization of the mammalian processing prohormone enzyme as members of the multidomain yeast kexin family. More recent applications of methods of molecular biology have greatly advanced our understanding of the nature and mode of action of these proteases.</p>","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/10.1159/000468898","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13004625","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: 22
The mechanism of decline of age-dependent enzymes in the red blood cell. 红细胞中年龄依赖性酶下降的机制。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468864
S Haram, D Carriero, C Seaman, S Piomelli
{"title":"The mechanism of decline of age-dependent enzymes in the red blood cell.","authors":"S Haram,&nbsp;D Carriero,&nbsp;C Seaman,&nbsp;S Piomelli","doi":"10.1159/000468864","DOIUrl":"https://doi.org/10.1159/000468864","url":null,"abstract":"<p><p>Buoyant density centrifugation on discontinuous gradients separates red blood cells (RBCs) according to age, as shown by radiolabelling experiments both in vitro and in vivo. Changes observed in these gradients reflect in vivo rates of decline. A progressive metabolic decline may render the RBC incapable of surviving stresses in the circulation. It was hypothesized that changes only take place at the reticulocyte-mature RBC transition. RBC hexokinase (HK) has two isozymes, one predominant in reticulocytes, the other in mature RBCs. We compared its decline in the density gradient, with that of pyrimidine-5'-nucleotidase (P5N), glutamate-oxaloacetate transaminase (GOT) and pyruvate kinase (PK). The decline of HK and P5N was clearly biphasic; for GOT and PK instead there was a single slope. Thus changes taking place at the reticulocyte-RBC transition are clearly identified by a biphasic slope in the gradient. The view of a progressive metabolic decline in vivo for the RBC therefore remains valid.</p>","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/10.1159/000468864","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12968132","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
Rapid accumulation of plasma acid-stable trypsin inhibitor in experimental acute renal injury. 血浆酸稳定型胰蛋白酶抑制剂在实验性急性肾损伤中的快速积累。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468865
M Maruyama, E Yoshida, M Sugiki, H Mihara, H Sumi, R Sakai
{"title":"Rapid accumulation of plasma acid-stable trypsin inhibitor in experimental acute renal injury.","authors":"M Maruyama,&nbsp;E Yoshida,&nbsp;M Sugiki,&nbsp;H Mihara,&nbsp;H Sumi,&nbsp;R Sakai","doi":"10.1159/000468865","DOIUrl":"https://doi.org/10.1159/000468865","url":null,"abstract":"<p><p>Acid-stable trypsin inhibitor (ASTI) activity was measured during experimental acute renal tubular dysfunction and glomerulonephritis in rats. A marked elevation of ASTI activity occurred at a very early stage of acute renal tubular damage, and the changes were observed prior to histological abnormalities or elevation of blood creatinine. No alteration in ASTI activity was observed at an early stage of experimental glomerulonephritis. The data obtained confirm that ASTI is excreted through the renal tubules and that the plasma ASTI concentration is very sensitive to renal tubular dysfunction.</p>","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/10.1159/000468865","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12968134","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
Prohormone processing by yeast proteases. 酵母蛋白酶对激素原的加工。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468899
Y Bourbonnais, D Germain, L Latchinian-Sadek, G Boileau, D Y Thomas
{"title":"Prohormone processing by yeast proteases.","authors":"Y Bourbonnais,&nbsp;D Germain,&nbsp;L Latchinian-Sadek,&nbsp;G Boileau,&nbsp;D Y Thomas","doi":"10.1159/000468899","DOIUrl":"https://doi.org/10.1159/000468899","url":null,"abstract":"<p><p>Investigations of the precursors of alpha-pheromone and killer toxin in the yeast Saccharomyces cerevisiae have defined the genes coding (KEX1 and KEX2) for the proteases which are responsible for their processing. In addition to processing at pairs of basic residues it is evident that yeast can also process at monobasic sites. We present data on the Kex1p and Kex2p enzymes, their cellular localization, and their post-translational modification. In addition initial characterisation of the monobasic specific protease and the isolation of mutants defective in this activity are presented. The use of the yeast system as a model for the processing of mammalian prohormones is discussed.</p>","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/10.1159/000468899","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13004626","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
Low activity of gamma-glutamyl transpeptidase in serum of acute intrahepatic cholestasis. 急性肝内胆汁淤积症患者血清γ -谷氨酰转肽酶活性低。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468863
E Kajiwara, K Akagi, H Tsuji, K Murai, M Fujishima
{"title":"Low activity of gamma-glutamyl transpeptidase in serum of acute intrahepatic cholestasis.","authors":"E Kajiwara,&nbsp;K Akagi,&nbsp;H Tsuji,&nbsp;K Murai,&nbsp;M Fujishima","doi":"10.1159/000468863","DOIUrl":"https://doi.org/10.1159/000468863","url":null,"abstract":"<p><p>Low gamma-glutamyl transpeptidase (gamma-GTP) activity in serum was observed in 11 patients with acute intrahepatic cholestasis (cholestatic hepatitis and fulminant hepatitis), despite a marked increase in bilirubin levels. Inhibitors of gamma-GTP were not detected in sera of these patients. Their gamma-GTP levels in the liver were significantly higher than those in chronic liver diseases. An electrophoretic study of liver gamma-GTP in acute intrahepatic cholestasis showed the same mobility as in chronic liver diseases. These results suggest that the low serum gamma-GTP activity in acute intrahepatic cholestasis is due to factors inhibiting the release of the enzyme from the liver.</p>","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/10.1159/000468863","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12851759","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: 5
Ultrasonic baths as substitutes for shaking incubator baths. 超声波浴代替摇箱浴。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468867
N S Radin, G S Shukla
{"title":"Ultrasonic baths as substitutes for shaking incubator baths.","authors":"N S Radin,&nbsp;G S Shukla","doi":"10.1159/000468867","DOIUrl":"https://doi.org/10.1159/000468867","url":null,"abstract":"<p><p>An easily assembled incubation bath for enzyme work is described. The bath is made from commercially available units: an ultrasonic bath of the type used for cleaning and a temperature-controlling device. The device is not only much cheaper, quieter, and more compact than a commercially built shaking-type bath, but is also gives superior mixing of heterogeneous enzyme incubation samples, particularly those containing tissue homogenates or subcellular particles.</p>","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/10.1159/000468867","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12968136","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
Glucose-6-phosphate dehydrogenase Lodi844C: a study on its expression in blood cells and muscle. 葡萄糖-6-磷酸脱氢酶Lodi844C在血细胞和肌肉中的表达研究。
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468887
P Ninfali, N Bresolin, L Baronciani, F Fortunato, G Comi, M Magnani, G Scarlato
{"title":"Glucose-6-phosphate dehydrogenase Lodi844C: a study on its expression in blood cells and muscle.","authors":"P Ninfali,&nbsp;N Bresolin,&nbsp;L Baronciani,&nbsp;F Fortunato,&nbsp;G Comi,&nbsp;M Magnani,&nbsp;G Scarlato","doi":"10.1159/000468887","DOIUrl":"https://doi.org/10.1159/000468887","url":null,"abstract":"Glucose-6-phosphate dehydrogenase (G6PD) deficiency was found in erythrocytes, lymphocytes and muscle of an Italian male, whose family has lived for at least three generations in Lodi (Lombardy, northern Italy). The subject was hospitalized for myalgia and dark urine after intense physical exercise, but no sign of anemia and chronic hemolysis were present at rest. Family studies revealed that the mother and the maternal aunt had the same enzymopathy. The enzyme-specific activity in red blood cells was 15% of control and the kinetic properties were the following: slower electrophoretic mobility; biphasic pH activity curve; slightly reduced thermal stability, and increased utilization of the substrate analogs. The analysis of our patient's DNA showed a G----C mutation at nucleotide 844 which causes an Asp----His amino acid change in position 282. This is the same mutation found by De Vita et al. in the G6PD Seattle-like variant. However, by following a new convention, we labelled our variant as G6PD Lodi844C. As far as the muscle is concerned, we found that the enzyme-specific activity in this tissue was 14% of control values, but cultured myotubes and myoblasts revealed a normal level of G6PD as well as skin fibroblasts. On the contrary in the same type of cultured cells obtained from G6PD Mediterranean subjects, the G6PD activity was about 20% of normal. Our results complete the characterization of this mutant enzyme, demonstrate the expression of the deficit in muscle and describe the enzyme behaviour in cultured cells.","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/10.1159/000468887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12986587","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: 28
Inhibition of sarcoplasmic reticulum Ca(2+)-ATPase activity by cadmium, lead and mercury. 镉、铅和汞对肌浆网Ca(2+)- atp酶活性的抑制作用
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468875
S Hechtenberg, D Beyersmann
{"title":"Inhibition of sarcoplasmic reticulum Ca(2+)-ATPase activity by cadmium, lead and mercury.","authors":"S Hechtenberg,&nbsp;D Beyersmann","doi":"10.1159/000468875","DOIUrl":"https://doi.org/10.1159/000468875","url":null,"abstract":"<p><p>The effect of Cd2+, Pb2+ and Hg2+ on the Ca(2+)-ATPase activity of sarcoplasmic reticulum from rabbit muscle was studied. The concentration of relevant free and complex species for the assay conditions have been computed. As a result, ATP hydrolysis was found to be inhibited with an IC50 value of 950 nmol/l free Cd2+ or 95 nmol/l free Pb2+. Although calculation of the free Hg2+ was not possible, the comparison of the IC50 values for total metal ions show that Hg2+ is the strongest inhibitor of enzyme activity. The inhibition by Cd2+ seems to be independent of substrate concentration, whereas the inhibitory effect of Pb2+ is lowered in the presence of higher MgATP concentrations. Our data illustrate that the three heavy metals are potent inhibitors of the Ca2+ pump. Therefore low concentrations of these metal ions may disturb intracellular Ca2+ homeostasis and act on Ca(2+)-mediated cell functions.</p>","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/10.1159/000468875","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13002307","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: 84
Presence of a truncated M-type subunit and altered kinetic properties of 6-phosphofructo-1-kinase isozymes in the brain of a dog affected by glycogen storage disease type VII. 受糖原储存病影响的犬脑中存在截断的m型亚基和6-磷酸果糖-1-激酶同工酶的动力学性质改变
Enzyme Pub Date : 1991-01-01 DOI: 10.1159/000468880
Y Mhaskar, U Giger, G A Dunaway
{"title":"Presence of a truncated M-type subunit and altered kinetic properties of 6-phosphofructo-1-kinase isozymes in the brain of a dog affected by glycogen storage disease type VII.","authors":"Y Mhaskar,&nbsp;U Giger,&nbsp;G A Dunaway","doi":"10.1159/000468880","DOIUrl":"https://doi.org/10.1159/000468880","url":null,"abstract":"<p><p>6-Phosphofructo-1-kinase (PFK) activity in the brain of a dog affected by glycogen storage disease type VII was only 31% of the PFK activity in the normal dog brain. PFK in the normal dog brain was composed of L-type, M-type and C-type subunits with apparent molecular weights of 78,000, 86,000, and 88,000, respectively, and subunit proportions (L:M:C) of 27:49:24. PFK in the affected dog brain was composed of nearly equal levels of the normal L-type and C-type subunits, but a normal M-type subunit was not detected. Using antidog muscle PFK IgG, immunoblots of gels containing partially purified PFK from the affected dog brain revealed a small amount of immunoreactive protein with an apparent molecular weight of 84,000, suggesting the presence of a truncated M-type subunit. Kinetic studies indicated that the PFK isozymes in the affected dog brain exhibited significantly different kinetic regulatory properties when compared to the PFK isozyme pool in the normal dog brain.</p>","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/10.1159/000468880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13002310","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: 8
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