Enzyme & protein最新文献_第6页

Enzyme-linked immunosorbent assay of carbamoylphosphate synthetase I: plasma enzyme in rat experimental hepatitis and its clearance. 大鼠实验性肝炎血浆酶甲氨甲酰磷酸合成酶ⅰ的酶联免疫吸附测定及其清除。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474991

M Ozaki, K Terada, M Kanazawa, S Fujiyama, K Tomita, M Mori

{"title":"Enzyme-linked immunosorbent assay of carbamoylphosphate synthetase I: plasma enzyme in rat experimental hepatitis and its clearance.","authors":"M Ozaki, K Terada, M Kanazawa, S Fujiyama, K Tomita, M Mori","doi":"10.1159/000474991","DOIUrl":"https://doi.org/10.1159/000474991","url":null,"abstract":"Carbamoylphosphate synthetase I (CPS I), a urea cycle enzyme, is located almost exclusively in the mitochondria of hepatocytes. The enzyme is unique in that it constitutes about 2-6% of total liver protein and is composed of a large subunit of 160 kD. We developed a sensitive enzyme-linked immunosorbent assay (ELISA) for measurement of the enzyme in plasma using an antibody against the rat enzyme. In galactosamine-induced rat acute hepatitis, plasma concentration of CPS I that was 1-2 micrograms/ml blood before the treatment, increased up to 125 micrograms/ml blood in 24 h after the treatment and decreased to a near control level in 72 h. Plasma concentration of ornithine carbamoyl-transferase (OCT), another urea cycle enzyme, reached a maximum in 24 h and then decreased a little more rapidly than that of CPS I. On the other hand, alanine aminotransferase activity reached a maximum in 36 h and decreased to a normal level in 96 h. In immunoblot analysis, the native CPS I polypeptide of 160 kD and its fragments of 140 and 125 kD were detected 24-48 h after the treatment. When purified rat CPS I and bovine OCT were injected intravenously into rats, the enzymes disappeared from blood roughly exponentially with apparent half-lives of about 67 and 18 min, respectively. Development of an ELISA for human CPS I and determination of the serum enzyme in various liver diseases remain to be performed.","PeriodicalId":11854,"journal":{"name":"Enzyme & protein","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000474991","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19789760","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: 17

Effects of pertussis toxin on signal transductions via P2-purinergic receptors in A-431 human epidermoidal carcinoma cells. 百日咳毒素对A-431人表皮样癌细胞p2 -嘌呤能受体信号转导的影响

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474992

K Sugita, K Kurihara, K Hosoi, T Atsumi, T Takahashi, M Kohno, T Ueha

引用次数: 4

Effect of proximal tubular glucose transport blockade on urinary enzyme excretions in hyperglycemic rats. 近端小管葡萄糖转运阻滞对高血糖大鼠尿酶排泄的影响。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474997

N Ishii, Z Ogawa, H Itoh, H Ikenaga, T Saruta

{"title":"Effect of proximal tubular glucose transport blockade on urinary enzyme excretions in hyperglycemic rats.","authors":"N Ishii, Z Ogawa, H Itoh, H Ikenaga, T Saruta","doi":"10.1159/000474997","DOIUrl":"https://doi.org/10.1159/000474997","url":null,"abstract":"To investigate proximal tubular dysfunction under hyperglycemic status, we infused 10% glucose solution into male Wistar rats with and without 0.16% phloridzin (a specific inhibitor of proximal tubular glucose transportation) and measured the urinary excretion rates of enzymes that are derived predominantly from proximal tubules. We used 10% mannitol solution and 0.9% saline as controls. Urinary excretion levels of N-acetyl-ss-D-glucosaminidase, alanine aminopeptidase, gamma-glutamyl transpeptidase and dipeptidyl aminopeptidase IV were significantly increased in the 10% glucose-loaded group. In contrast, these increased enzyme excretions were not observed in the 10% mannitol or 0.9% saline-loaded group. Moreover, addition of 0.16% phloridzin to 10% glucose solution completely prevented these increases in N-acetyl-beta-D-glucosaminidase, alanine aminopeptidase and gamma-glutamyl transpeptidase excretion, and slightly decreased dipeptidyl aminopeptidase IV excretion. At the end of the infusion study, a rise in renal cortical sorbitol concentration of the 10% glucose-loaded group was about 2 times higher than the 0.9% saline or 10% mannitol-loaded group. However, in the group that received both glucose and phloridzin, elevation of renal cortical sorbitol concentration was not observed. This study showed that glucose-load results in both abnormal enzymuria and renal cortical sorbitol accumulation; they were completely prevented by phloridzin.","PeriodicalId":11854,"journal":{"name":"Enzyme & protein","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000474997","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19763964","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

Insulin-degrading activity in experimental liver cirrhosis of the rat. 实验性肝硬化大鼠胰岛素降解活性的研究。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474989

M Auletta, S Antoniello, N Abrescia

引用次数: 4

Effect of grape seed tannins on the activity of some rat intestinal enzyme activities. 葡萄籽单宁对大鼠肠道酶活性的影响。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474969

K Tebib, J M Rouanet, P Besançon

{"title":"Effect of grape seed tannins on the activity of some rat intestinal enzyme activities.","authors":"K Tebib, J M Rouanet, P Besançon","doi":"10.1159/000474969","DOIUrl":"https://doi.org/10.1159/000474969","url":null,"abstract":"The present study was designed to investigate the effects of grape seed tannins on rat intestinal alkaline phosphatase (AP), sucrase and dipeptidyl peptidase IV (DPP IV) activities. An experiment was performed in vivo by dietary supplementation with 2% tannins; this diet was tested on an experimental group of rats; a control group received a diet without tannins. After 31 days, tannins intake significantly decreased middle-jejunal AP from 123 to 45 mU/mg protein and sucrase activities from 310 to 195 mU/mg protein, while no significant difference appeared at the duodenal stage (p < 0.05). Ileal DPP IV activity was also significantly reduced (p < 0.05) from 190 to 110 mU/mg protein after tannin intake. Using in vitro experiments on purified brush border membranes, AP activity was found to be inhibited by grape tannins; this inhibition was prevented by the detergent Triton X-100. The addition of pancreatic-biliary (PB) juice to the incubation medium prevented or reversed the tannin-inhibited enzyme activity. The present data indicate that in the duodenal lumen, alkalinity and detergency from the PB secretion neutralized the ability of tannins to inactivate brush border hydrolase activities and suggest that enzyme inhibition took place once bile salts were reabsorbed while moving down the gut. This was confirmed by in vitro experiments where sucrase and DPP IV activities inhibited by grape seed tannins were largely recovered after the addition of PB juice to the incubation medium.","PeriodicalId":11854,"journal":{"name":"Enzyme & protein","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000474969","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18787427","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

A sensitive enzyme-linked immunosorbent assay of serum ornithine carbamoyltransferase. 血清鸟氨酸氨基甲酰转移酶的灵敏酶联免疫吸附测定。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474964

Y Watanabe, S Mori, M Ozaki, S Fujiyama, T Sato, M Mori

引用次数: 5

Induced expression of alpha-enolase in differentiated diffuse large cell lymphoma. α -烯醇化酶在分化性弥漫性大细胞淋巴瘤中的诱导表达。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474967

R M Mohammad, M Y Hamdan, A al-Katib

引用次数: 10

Spectroscopic studies on angiotensin I-converting enzyme. 血管紧张素i转换酶的光谱研究。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474999

B Baudin, N Mario, S Gaba, J Giboudeau

{"title":"Spectroscopic studies on angiotensin I-converting enzyme.","authors":"B Baudin, N Mario, S Gaba, J Giboudeau","doi":"10.1159/000474999","DOIUrl":"https://doi.org/10.1159/000474999","url":null,"abstract":"We used near and far UV spectrophotometry for the re-evaluation of the molar extinction coefficient at 280 nm (epsilon 280) of pulmonary angiotensin-converting enzyme (ACE), for the determination of its tryptophan and tyrosine contents and to follow-up guanidine denaturation. ACE purity was assessed by both SDS-PAGE and capillary electrophoresis performed in denaturing conditions. The maxima of the near UV spectrum of purified ACE, dissolved in phosphate buffer pH 6.5, was at 279 nm; with an estimated M(r) of 160 kD, epsilon 280 of native ACE was 1.5 +/- 0.05 x 10(5) (mol/l)-1 x cm-1. Denaturation of ACE by 6 mol/l guanidine hydrochloride produced a hypochromic effect of 23% at 280 nm and led to a blue shift of 3.5 nm. In guanidine solution, absorbance measurements at 288 and 280 nm predicted a ratio of 1 between tyrosine and tryptophan, whereas it was 1.8 with the measure of the amplitude of the spectral bands at 283 and 292 nm of the second derivative of the near UV spectrum. Unfolding of the peptide chain in 6 mol/l guanidine was also well characterized by the second derivative of the far UV spectrum, in parallel with the complete loss of enzymatic activity although the protein remained whole as judged on SDS-PAGE. We also re-evaluated ACE zinc content by atomic absorption spectroscopy and demonstrated that ACE molecule obviously contains two zinc atoms.","PeriodicalId":11854,"journal":{"name":"Enzyme & protein","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1159/000474999","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19765115","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: 6

Creatine kinase activity decrease with short-term freezing. 肌酸激酶活性随短期冷冻而降低。

Enzyme & protein Pub Date : 1994-01-01 DOI: 10.1159/000474994

E I Lev, I Hendler, R Siebner, Z Tashma, M Wiener, I Tur-Kaspa

引用次数: 12

Bovine lens multicatalytic proteinase complex. 牛晶状体多催化蛋白酶复合物。

Enzyme & protein Pub Date : 1993-01-01 DOI: 10.1159/000468679

B J Wagner, J W Margolis, I Singh

引用次数: 7