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An improved assay for UDPglucose pyrophosphorylase and other enzymes that have nucleotide products. 一种改进的udp葡萄糖焦磷酸化酶和其他具有核苷酸产物的酶的测定方法。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969730
R G Duggleby, H L Peng, H Y Chang
{"title":"An improved assay for UDPglucose pyrophosphorylase and other enzymes that have nucleotide products.","authors":"R G Duggleby,&nbsp;H L Peng,&nbsp;H Y Chang","doi":"10.1007/BF01969730","DOIUrl":"https://doi.org/10.1007/BF01969730","url":null,"abstract":"<p><p>UDPglucose pyrophosphorylase catalyses the interconversion UDPglucose plus pyrophosphate and glucose 1-phosphate plus UTP. Several assay methods for this enzyme have been described but the only one that can be used to investigate the specificity with respect to various UDPsugars is based on coupling to UTP formation. This assay employs phosphoglycerate kinase to catalyse the formation 1,3- bisphosphoglycerate which is then used to oxidise NADH in the presence of glyceraldehyde 3-phosphate dehydrogenase. We have found that the activity of phosphoglycerate kinase towards UTP is low which limits the usefulness of the assay to very low rates, in agreement with the published recommendation of Hansen et al. Here it is shown that the dynamic range of the assay is increased by more than five fold on addition of nucleoside diphosphate kinase and ADP, which convert UTP to the preferred phosphoglycerate kinase substrate, ATP. It is also shown that the improved assay is suitable for enzymes with other nucleotide triphosphate products.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"568-72"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969730","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672102","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
Dissociation constants of water-insoluble carboxylic acids by 13C-NMR. pK(a)s of mesobiliverdin-XIII alpha and mesobilirubin-XIII alpha. 水不溶性羧酸的13C-NMR解离常数。中胆红素- xiii α和中胆红素- xiii α的pK(a)s。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969747
D A Lightner, D L Holmes, A F McDonagh
{"title":"Dissociation constants of water-insoluble carboxylic acids by 13C-NMR. pK(a)s of mesobiliverdin-XIII alpha and mesobilirubin-XIII alpha.","authors":"D A Lightner,&nbsp;D L Holmes,&nbsp;A F McDonagh","doi":"10.1007/BF01969747","DOIUrl":"https://doi.org/10.1007/BF01969747","url":null,"abstract":"<p><p>High-field 13C-NMR of 13C-enriched compounds in dilute aqueous d6-Me2-SO solutions provides a simple, accurate method for measuring pK(a)s of sparingly soluble carboxylic acids. Using this method, we found the pK(a)s of mesobilirubin-XIII alpha to be 4.2 and 4.9, much lower values than reported recently for bilirubin, and of mesobiliverdin-XIII alpha to be 3.9 and 5.3.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"639-42"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969747","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19671351","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
Inhibition of lipid peroxidation by diterpenoid from Podocarpus nagi. 龙柏二萜对脂质过氧化的抑制作用。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969731
H Haraguchi, H Ishikawa, S Sakai, B P Ying, I Kubo
{"title":"Inhibition of lipid peroxidation by diterpenoid from Podocarpus nagi.","authors":"H Haraguchi,&nbsp;H Ishikawa,&nbsp;S Sakai,&nbsp;B P Ying,&nbsp;I Kubo","doi":"10.1007/BF01969731","DOIUrl":"https://doi.org/10.1007/BF01969731","url":null,"abstract":"<p><p>A diterpenoid, totarol (1), from Podocarpus nagi was evaluated as an antioxidant. This diterpenoid inhibited autoxidation of linoleic acid. Mitochondrial and microsomal lipid peroxidation induced by Fe(III)-ADP/NADH or Fe(III)-ADP/NADPH were also inhibited. Nagilactone E (2), a norditerpene lactone isolated from the same source, had no antioxidative activity. Furthermore, totarol protected red cells against oxidative hemolysis. This diterpene was shown to be effective in protecting biological systems against oxidative stresses.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"573-6"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969731","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672103","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
Altered axon terminals containing concentric lamellar bodies of cerebellar Purkinje cells in Mongolian gerbil. 蒙古沙鼠小脑浦肯野细胞轴突末端含有同心板层体的改变。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969722
I K Takeuchi, Y K Takeuchi, Y Murashima, A Seto-Ohshima
{"title":"Altered axon terminals containing concentric lamellar bodies of cerebellar Purkinje cells in Mongolian gerbil.","authors":"I K Takeuchi,&nbsp;Y K Takeuchi,&nbsp;Y Murashima,&nbsp;A Seto-Ohshima","doi":"10.1007/BF01969722","DOIUrl":"https://doi.org/10.1007/BF01969722","url":null,"abstract":"<p><p>Altered axon terminals containing concentric lamellar bodies were observed in cerebellar and vestibular nuclei of the Mongolian gerbil. The terminals increased in number from 30 days of age onward, and reached about tenfold at 360 days. The numbers were the same in two gerbil strains with different susceptibility to spontaneous motor seizures by various stimuli, but about threefold those in Slc:Wistar rat.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"531-4"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969722","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672219","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 some properties of hemagglutinin from the Myxomycete, Physarum polycephalum. 多头绒泡菌黏菌血凝素的纯化及其性质研究。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969725
M Yokota, K Nitta
{"title":"Purification and some properties of hemagglutinin from the Myxomycete, Physarum polycephalum.","authors":"M Yokota,&nbsp;K Nitta","doi":"10.1007/BF01969725","DOIUrl":"https://doi.org/10.1007/BF01969725","url":null,"abstract":"<p><p>A new hemagglutinin was isolated from the plasmodium of Physarum polycephalum by salting out with ammonium sulphate followed by chromatography on DE-32, DEAE-Toyopearl and hydroxyapatite. This hemagglutinin, named physarumin, was purified 1000-fold over crude extracts. The molecular weight of physarumin was determined to be 22,000 by size exclusion chromatography on Bio-Gel P-60 and 8,700 by SDS-polyacrylamide gel electrophoresis. Physarumin agglutinated rabbit, guinea pig, horse and human erythrocytes. Physarumin-induced hemagglutination was inhibited by fetuin and alpha 1-acid glycoprotein, but not by commercially available mono- and disaccharides. Hemagglutinating activity was blocked by EDTA, and was restored by adding Ca2+ but not by Mg2+.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"544-8"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969725","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672097","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
The accessory gland proteins in male Drosophila: structural, reproductive, and evolutionary aspects. 雄性果蝇的副腺蛋白:结构、生殖和进化方面。
Experientia Pub Date : 1996-06-15 DOI: 10.1007/BF01969718
P S Chen
{"title":"The accessory gland proteins in male Drosophila: structural, reproductive, and evolutionary aspects.","authors":"P S Chen","doi":"10.1007/BF01969718","DOIUrl":"https://doi.org/10.1007/BF01969718","url":null,"abstract":"<p><p>Recent results from biochemical and molecular genetic studies of the accessory gland proteins in male Drosophila are reviewed. The most prominent feature is the species-specific variability. However, the analysis of the sex peptide in D. melanogaster shows that there is a strong homology in the molecular structure to the closely related sibling species, and that divergence increases with increasing phylogenetic distance. For this reason the sex peptide, after being transferred to the female genital tract during copulation, reduces receptivity and increases oviposition only in virgin females belonging to the same species group and subgroup. Even though studies were hitherto limited to a small number of the secretory components, it is evident that the accessory gland proteins play a key role in reproductive success of the fruit fly by changing female sexual behavior, supporting sperm transfer, storage and displacement. Thus, genes encoding the accessory gland proteins are apparently under strong evolutionary selection.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 6","pages":"503-10"},"PeriodicalIF":0.0,"publicationDate":"1996-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01969718","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19672218","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: 47
Conservation, evolution, and specificity in cellular control by protein phosphorylation. 蛋白质磷酸化在细胞控制中的保护、进化和特异性。
Experientia Pub Date : 1996-05-15 DOI: 10.1007/BF01919314
H W Hofer
{"title":"Conservation, evolution, and specificity in cellular control by protein phosphorylation.","authors":"H W Hofer","doi":"10.1007/BF01919314","DOIUrl":"https://doi.org/10.1007/BF01919314","url":null,"abstract":"<p><p>The glycolytic control enzyme phosphofructokinase from the parasitic nematode Ascaris lumbricoides is regulated by reversible phosphorylation. The enzyme is phosphorylated by an atypical cyclic adenosine monophosphate (cAMP)-dependent protein kinase whose substrate specificity deviates from that of the mammalian protein kinase. This variation is explained by structural peculiarities on the surface part of the catalytic groove of the protein kinase. Also, the protein phosphatases responsible for the reversal of phosphorylation appear to act specifically in glycolysis and are different from those participating in regulation of glycogenolysis.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 5","pages":"449-54"},"PeriodicalIF":0.0,"publicationDate":"1996-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01919314","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19618515","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
Some thoughts on the importance of insulin in the regulation of the blood glucose level. 关于胰岛素在调节血糖水平中的重要性的一些思考。
Experientia Pub Date : 1996-05-15 DOI: 10.1007/BF01919310
E A Newsholme, G Dimitriadis
{"title":"Some thoughts on the importance of insulin in the regulation of the blood glucose level.","authors":"E A Newsholme,&nbsp;G Dimitriadis","doi":"10.1007/BF01919310","DOIUrl":"https://doi.org/10.1007/BF01919310","url":null,"abstract":"<p><p>Insulin can influence rates of glucose utilization by muscle and possibly other tissues via both direct and indirect effects. It can control the rate of fatty acid mobilization from adipose tissue and the rate of fatty acid oxidation in muscle, and the latter inhibits glucose utilization and oxidation. Insulin may influence the levels of insulin-like growth factors I and II, both of which have effects on rates of glucose utilization by muscle. The inter-tissue cycle between glucose and lactate-the Cori cycle, which is influenced by insulin-may provide another novel mechanism for control of blood glucose. How far other anti-insulin hormones affect these processes is not clear.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 5","pages":"421-5"},"PeriodicalIF":0.0,"publicationDate":"1996-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01919310","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19618512","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
Hyperinsulinemia, hyperproinsulinemia and insulin resistance in the metabolic syndrome. 代谢综合征中的高胰岛素血症、高胰岛素原血症和胰岛素抵抗。
Experientia Pub Date : 1996-05-15 DOI: 10.1007/BF01919311
J Schrezenmeir
{"title":"Hyperinsulinemia, hyperproinsulinemia and insulin resistance in the metabolic syndrome.","authors":"J Schrezenmeir","doi":"10.1007/BF01919311","DOIUrl":"https://doi.org/10.1007/BF01919311","url":null,"abstract":"<p><p>For better comprehension of the metabolic syndrome, it is necessary to differentiate the effect of insulin on glucose metabolism on the one hand, and on other metabolic activities on the other hand. Whereas glucose utilization is affected by insulin resistance, the effect of insulin on lipid metabolism, ion and aminoacid transport does not seem to be diminished. Lipid metabolism, however, seems to play a crucial role in the induction of the vicious cycle. Increased energy and fat ingestion may be due to an increased number of galanin secreting cells in the hypothalamus. The excessive fat intake results in an increased rate of release of insulin and increased influx of triglycerides into the blood. From these triglycerides an excess of free fatty acids is released by the action of lipoprotein lipase. The increased plasma free fatty acid level then results in insulin resistance affecting glucose metabolism. Also, these free fatty acids may impair the secretion of insulin. Induction of insulin resistance results in higher glucose levels, which may cause hyperinsulinemia. Hyperinsulinemia maintains the elevation of triglycerides. When diabetes becomes overt and elevated glucose levels prevail, the hyperinsulinism acts on the metabolic pathways which are still sensitive to insulin, namely lipid metabolism, aminoacid transport and ion transport.</p>","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 5","pages":"426-32"},"PeriodicalIF":0.0,"publicationDate":"1996-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01919311","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19618513","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: 30
Metabolic regulation--physiological and medical aspects. 代谢调节——生理和医学方面。
Experientia Pub Date : 1996-05-15 DOI: 10.1007/BF01919305
G Wegener, U Krause, E A Newsholme
{"title":"Metabolic regulation--physiological and medical aspects.","authors":"G Wegener,&nbsp;U Krause,&nbsp;E A Newsholme","doi":"10.1007/BF01919305","DOIUrl":"https://doi.org/10.1007/BF01919305","url":null,"abstract":"","PeriodicalId":12087,"journal":{"name":"Experientia","volume":"52 5","pages":"391-5"},"PeriodicalIF":0.0,"publicationDate":"1996-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/BF01919305","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19618600","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
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