Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the autolytic phase of growth Schizophyllum commune lost 62% of its dry weight in 70 days of incubation. The variations in the activity of some lytic enzymes were studied in the culture fluid and mycelial extracts during growth and autolysis of this fungus. The enzymes 1,3-beta-glucanase (exoglucanase), 1,3(4)-beta-glucanase (endoglucanase), alpha-amylase, and invertase behaved in the same way in culture fluid and mycelial extract, but their activities were much higher in the culture fluid. The enzyme activities increased during autolysis, but then decreased at the end of this period except in the case of alpha-amylase which remained high. It was only possible to detect 1,6-beta-glucanase, cellulase, and polygalacturonase activities at certain times during the autolytic phase of growth. The enzyme chitinase was not detected and 1,3-alpha-glucanase (S-glucanase) occurred in the mycelial extract at a higher concentration than in the culture fluid. A decrease in the activity of this enzyme in the mycelial extract and an increase in the culture fluid occurred during autolysis. The enzyme 1,3-alpha-glucanase exhibited two optima pH, one at 6.0 and the other at 8.0. The Km value for the latter was 0.02 M at pH 5.5 in borate-citrate-phosphate buffer.
Can J Microbiol 1980 Sep
PMID:Lytic enzymes in the autolysis of Schizophyllum commune with special reference to 1,3-alpha-glucanase. 697 66

The protein content and the activities of alkaline phosphatase, maltase, and sucrase were measured at 0800, 1000, 1200, 1400, and 1600 in saline extracts of the proximal small bowels of germfree and of ex-germfree mice colonized with an indigenous microbiota. In extracts prepared from germfree mice, the total activities of all of the enzymes were relatively constant throughout the sampling period. Likewise, the total activity of alkaline phosphatase in extracts prepared from associated mice varied little as a function of time. By contrast, the total activities of maltase and sucrase in the extracts from these latter animals varied significantly from sample to sample. The total activity levels in extracts from germfree mice were approximately twofold greater than the levels in extracts from associated mice. The specific activities of alkaline phosphatase and sucrase did not vary from sample to sample in extracts prepared from either type of mouse. In contrast, the specific activity of maltase in extracts prepared from both germfree and associated mice differed significantly from sample to sample. The specific activities of all three enzymes were greater in extracts from germfree animals than in those from associated animals. The protein content of extracts prepared from germfree mice also was greater than that of extracts prepared from associated animals at every sampling time. The amount of protein extractable from the mucosa of the small bowels of the former animals varied significantly at different sampling times during the day, whereas the amount of protein extractable from the tracts of associated animals remained relatively constant throughout the day. The indigenous microbiota apparently stabilizes in some way the amount of protein extractable from the mucosa of the mouse small bowel.
Appl Environ Microbiol 1981 Sep
PMID:Influence of indigenous microbiota on amount of protein and activities of alkaline phosphatase and disaccharidases in extracts of intestinal mucosa in mice. 702 54

The intestinal brush-border disaccharidases most resistant to pancreatic protease digestion in vitro are lactase and trehalase. When compared to maltase and sucrase, they are also those which showed the largest increase during development of guinea pig fetuses. These results suggest that pancreatic proteases may play a role in the control of brush-border disaccharidase activities during fetal development.
Biomedicine 1981 Sep
PMID:Control of disaccharidase activities in brush-border membranes of guinea pig fetuses: a role of pancreatic proteases? 702 47

Experimentally induced diabetes enhances the specific activity of several microvillus membrane proteins in the rat small intestine. The increase in the specific activity of sucrase-isomaltase has been shown by others to be due to an increase in enzyme protein, raising the possibility that diabetes induces a generalized increase in microvillus membrane proteins. Since intramembrane particles (IMPs) seen on freeze-fracture replicas of microvillus membranes are thought to represent integral membrane proteins, we compared microvillus IMP densities in diabetic rats with those in control rats. In addition, mucosal sucrase, maltase, and alkaline phosphatase specific activities were measured in all animals. Diabetic rats had significantly increased sucrase and maltase but not alkaline phosphatase specific activities compared with control rats. The density of microvillus IMPs on both the protoplasmic and extracellular fracture faces of undifferentiated crypt cells and villus absorptive cells was not increased in experimental diabetes. These data indicate that diabetes does not result in a generalized increase in microvillus membrane proteins. Thus the enhanced activity of microvillus membrane proteins in diabetes appears to be highly selective.
Dig Dis Sci 1982 Sep
PMID:Structural features of the rat small intestinal microvillus membrane in acute experimental diabetes. 704 26

Both corticosterone and T4 have been previously implicated as causal factors in the ontogenic increases in jejunal sucrase and maltase activities during the third week of life in the rat. Furthermore, it is known that the administration of exogenous T4 during the developmental period causes significant increases in serum corticosterone concentrations. To determine whether the effects of T4 on sucrase and maltase are secondary to the corticosterone rise, we examined the effect of T4 administration in adrenalectomized (adX) pups. Serum corticosterone was measured in all operated animals. Some of the adX pups had substantial concentrations of circulating corticosterone. In adX pups with serum corticosterone levels below 0.1 microgram/dl, there was no effect of T4 on either maltase or sucrase activity. We also studied the effect of propylthiouracil-induced hypothyroidism on sucrase and maltase. At 21 days of age, both enzyme activities were significantly reduced in hypothyroid pups. Injections of either T4 or cortisone acetate were equally effective in restoring activities to normal. For sucrase, there was no further increase in activity when both hormones were administered. For maltase, the combined treatment gave activities that were significantly higher than those with either hormone alone. We conclude that for both sucrase and maltase, the effects of changes in thyroid status are primarily due to the accompanying changes in serum corticosterone. The normal rate of development of both enzymes appears to be principally under glucocorticoid control, although for maltase, T4 may have a facilitory action.
Endocrinology 1982 Sep
PMID:Relative importance of corticosterone and thyroxine in the postnatal development of sucrase and maltase in rat small intestine. 704 75

A mutation causing resistance to carbon catabolite repression in gene HEX2, mutant allele hex2-3, causes an extreme sensitivity to maltose when in combination with the genes necessary for maltose metabolism. This provided a convenient system for the selective isolation of mutations in genes specifically required for maltose metabolism and other genes involved in general carbon catabolite repression. In addition to reversion of the hex2-3 allele, mutations in three other genes were detected. These genes were called CAT1, CAT3, and MUR1 and in a mutated form abolished maltose inhibition caused by mutant allele hex2-3. Mutant alleles cat1 and cat3 also restored normal repression in the presence of the hex2-3 allele. Segregants having only mutant alleles cat1 or cat3 were obtained by tetrad analysis. These segregants could not grow on nonfermentable carbon sources. Mutant alleles of gene CAT1 were allelic to a mutant allele cat1-1 previously isolated (Zimmermann et al., Mol. Gen. Genet. 151:95-103). Such mutants prevented derepression not only of the maltose catabolizing system, the selected property, but also of glyoxylate shunt and gluconeogenic enzymes. However, respiratory activities and invertase formation were not affected under derepressing conditions. cat3 mutants had the same phenotypic properties as cat1 mutants. This showed that carbon metabolism in yeast cells is under a very complex and ramified control of repressing and derepressing genes, which are interdependent.
J Bacteriol 1982 Sep
PMID:New genes involved in carbon catabolite repression and derepression in the yeast Saccharomyces cerevisiae. 705 76

The effect of resuming food intake after a period of starvation (refeeding) on the specific activities of selected rat intestinal enzymes was determined. The rate of weight gain was higher in refed animals than in control animals, without a difference in food intake. Fasting caused intestinal atrophy which reversed rapidly on refeeding. Fasting decreased the specific activities of sucrase, maltase, and galactokinase, but did not affect the specific activities of hexokinase, pyruvate kinase, or crypt thymidine kinase. Sucrase, maltase, hexokinase, pyruvate kinase, and thymidine kinase specific activities all rose above control values during refeeding. The overshoot in intestinal enzyme specific activities may help promote the rapid weight gain observed in refed rats and is an integral part of the total adaptation to fasting and refeeding.
Am J Clin Nutr 1982 Sep
PMID:Refeeding after a fast in rats: effects on small intestinal enzymes. 705 2

The effect of four raw legume diets: field beans (Vicia faba) (RFB), navy beans (Phaseolus vulgaris) (RNB), soybeans (Glycine soja) (RSB) and bitter vetch (VICIA ervilia) (RBV), on disaccharidase activities in chick small intestine have been studied. Maltase and sucrase activities, which vary with age, were determined in 1 to 60 day old animals, RFB and RBV diets had no effect on maltase activity and only increased sucrase activity in 60 day old chicks. Both maltase and sucrase activities decreased in chicks on RSB diet, regardless of their age, and the decrease was even more pronounced in chicks on RNB diet. Contrarywise, chicks fed on autoclaved navy beans and soybeans showed a considerably higher activity of these disaccharidases.
Rev Esp Fisiol 1980 Sep
PMID:Effect of raw legume diets on disaccharidase activity in the small intestine of chicks. 719 9

A continuous optical method for the assay of glucose-releasing hydrolases is reported. Particular emphasis is given to the assay of purified sucrase from rabbit small intestine. The procedure requires glucose dehydrogenase and mutarotase. In the presence of the latter enzyme, the initial lag is substantially shortened when glucose is released as alpha-anomer. Under the test conditions used, the method shows a good proportionality up to an activity of 0.2 units/3 ml and may also be applied for measuring the activity in crude homogenates.
Experientia 1980 Sep 15
PMID:Continuous optical assay of sucrase and other glucosidases. 741 35

Investigations of the course disaccharidases take in duodenum and pancreas were made with 20 suckling lambs (straw litter, supplementary feed from 3rd week onwards) at an age between 1 and 30 days. In the first week of the Lambs' lives the activity of lactase in the duodenal mucosa was highest. In the following weeks there was a slightly falling tendency. During the first four weeks of the lambs' lives there were no statistically significant differences concerning the maltase activities in the duodenal mucosa. At the beginning of the first and at the end of the fourth week of the lambs' lives the activity of lactase in the content of the duodenum was significantly lower than at the end of the first and up to the third week. The maltase in the contents of the duodenum showed a significantly higher activity at the end of the fourth week of life. Enzyme activities in the contents of the duodenum were significantly lower then those in the mucosa. After maltase activity in the pancreas had shown high values in the first two days of life, it decreased distinctly toward the end of the first week and than increased again up to the fourth week of life. In the period investigated, saccharase activity in the duodenal mucosa and in the contents of the duodenum could not be detected in any lamb.
Arch Tierernahr 1980 Sep
PMID:[Investigations of the activity of disaccharidases in growing sheep. 1. Suckling lambs from birth to an age of 4 weeks]. 745 64


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