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 this paper, we analyze the factors involved in the precocious increase of sucrase activity evoked by the early feeding of sucrose in suckling rats, and particularly, the role of diarrhea and stress in this phenomenon. Ten-day-old rats were removed from their mothers and gavage fed for 4 days at 3-h intervals either a basic low carbohydrate milk formula (10.8% fat, 8% protein, 1.4% carbohydrate; all by weight/volume) or basic low carbohydrate milk with: lactose (13%), fructose (13%), or Polycose (2%, 6%, or 13%); all formulas were isocaloric. Feeding the formula containing fructose or high (13%) Polycose led to diarrhea and evoked a concurrent increase of small intestinal sucrase activity. In further experiments, 11-day-old rats were fed the basic formula, the lactose (13%), the fructose (13%), and a sucrose (13%) formula for 8 h between 2 a.m. and 10 a.m. Also, 10-day-old rats were fed 0.5 ml of a solution of 5% mannitol in water while nursing with their mothers. The serum corticosterone levels were substantially increased within 8 h after the initiation of feedings with sucrose and fructose milks and the mannitol solution. The mannitol-fed rats also developed diarrhea within a day in association with a marked increase in sucrase activity. We conclude that a precocious increase of sucrase activity in the small intestine of suckling rats by dietary sugars is not caused by substrate induction, but is mainly due to the effect of stress. The stress is caused by diarrhea which is evoked by the feeding of indigestible and/or unabsorbable amounts of sugar.
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PMID:Precocious increase of sucrase activity by carbohydrates in the small intestine of suckling rats. I. Significance of the stress effect of sugar-induced diarrhea. 404 May 66

To determine whether zinc has a specific role on intestinal growth and function, three groups of male weanling Sprague-Dawley rats were fed a semipurified zinc-deficient diet: ad libitum fed group received powdered diet and water containing 25 ppm of zinc; force fed (ZN, ZD) groups were fed identical amounts of diet to the ad libitum fed group by intragastric infusion three times per day. The diets were aqueous suspensions made with either deionized water (ZD) or water containing 25 ppm of zinc (ZN), and additional drinking water with (ZN) or without zinc (ZD) was offered ad libitum. Rats were sacrificed after 8 days of feeding. The ZD group showed growth arrest, perioral and periorbital dermal lesions, and abdominal distention within 8 days of feeding. Mucosal DNA, protein, sucrase, maltase, lactase, leucine aminopeptidase, and alkaline phosphatase were significantly decreased in the ZD group, whereas intestinal length, weight, and mucosal weight were unaltered. These results suggest that short-term isolated zinc deficiency impairs growth, digestion, and absorption in the rat small intestine, even in the absence of associated protein calorie malnutrition.
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PMID:Effects of short-term isolated zinc deficiency on intestinal growth and activities of several brush border enzymes in weaning rats. 408 Apr 54

Raffinose hydrolysis was studied in Saccharomyces rouxii. The responsible enzyme was identified as a beta-fructofuranosidase (EC 3.2.1.26), which has a pH optimum of 5.5 and a K(m) of 83 mM for raffinose. This enzyme was cryptic in cells from a 3-day culture. A 2-min treatment with 0.1 volume of ethyl acetate in sodium acetate buffer (pH 6) gave complete expression of the enzyme, which was still retained by the cell. Ghosts were prepared by modifying membrane structure with small basic proteins in distilled water, and after washing they showed the full complement of enzymatic activity. The enzyme remained cryptic in osmotically protected spheroplasts; however, after lysis (by dilution) release, as well as expression, was effected. Mechanical disruption of fresh cells revealed and released all of the enzyme. Cells in early stationary phase had all of their beta-fructofuranosidase in a cryptic state. Aging yielded fractional expression of activity; initially this was proportional to cell death, but later the degree of expression exceeded the death rate. Media from aged cultures or cell-free extracts of aged cells were not effective in revealing the cryptic enzyme of younger cells. S. rouxii beta-fructofuranosidase has a different autolytic-release pattern from its counterpart in S. cerevisiae. Also, high concentrations of glucose do not repress the S. rouxii enzyme. The beta-fructofuranosidase in young cells of S. rouxii must be enclosed by the protoplasmic membrane or a special vesicular structure. This system was compared with other Saccharomyces species in connection with the translocation of enzymes across the protoplasmic membrane.
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PMID:Expression of cryptic beta-fructofuranosidase in Saccharomyces rouxii. 445 87

The utilization of sucrose by a cariogenic strain of Streptococcus mutans was studied. The soluble and cell-bound sucrose-dependent, polymer-forming sucrase activities constitutively produced by the bacteria during growth on glucose were measured. About eight times more dextransucrase activity was present than levan-sucrase activity. During various states of growth on sucrose, S. mutans accumulated two to five times more insoluble and water-soluble dextran than levan. Although more of the fructosyl moiety of sucrose was therefore available to the cells, the glucosyl portion of the disaccharide was preferentially incorporated into cellular macromolecules. Glucose was shown to inhibit the utilization of fructose by S. mutans.
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PMID:Preferential utilization of the glucosyl moiety of sucrose by a cariogenic strain of Streptococcus mutans. 463 86

There was a significant depression of the activities of intestinal lactase, invertase, and alkaline phosphatase in rats given drinking water containing 2.5 mg of colchicine per 100 ml. Activities of intestinal maltase, aspartate transcarbamylase, and dihydroorotase were not affected by the drug. Injection of colchicine (1 mg/kg) caused depression of intestinal invertase activity within 8 hr. Investigation of the effect of colchicine on the disaccharides in vitro demonstrated that invertase and maltase were not affected by concentrations up to 125 mg/100 ml. Intestinal lactase was inhibited by concentrations exceeding 5 mg/100 ml. Calculation of the concentration of colchicine present in the intestine, after a single injection, indicated that the in vivo effect of colchicine was not due to simple enzyme inhibition. Histological examination showed an increase in crypt cells but no decrease in the length of the villi. Cellular migration along the villi, as well as activity of uridine kinase in intestinal mucosa, was increased in colchicine-treated rats. It was concluded that colchicine did not depress intestinal invertase, lactase, and alkaline phosphatase by decreasing cellular renewal, but rather it exerted its effect directly on the differentiated cells of the villus.
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PMID:Effect of colchicine on intestinal disaccharidases: correlation with biochemical aspects of cellular renewal. 541 79

1. A study was made of the composition and structure of walls isolated from yeast grown in continuous culture at different rates, under three conditions of glucose limitation in which the concentrations of glucose and ammonium sulphate in the medium and the oxygen-transfer rate in the culture were varied, and one condition of NH(4) (+) limitation. 2. The contents of total glucan and total mannan in the walls were relatively little affected by the growth rate under any of the four sets of conditions. The phosphorus and protein contents of walls from yeast grown under each of the four conditions increased as the growth rate was decreased. Walls from yeast grown under NH(4) (+) limitation contained only half as much protein as walls from cells grown under glucose limitation. The proportion of lipid was greatest in walls from yeast grown under NH(4) (+) limitation. 3. A procedure was devised for fractionating isolated walls, based on the ease with which the glucan and mannan were extracted with water and with hot and cold 6% (w/v) potassium hydroxide solution. The percentage of glucan, mannan, protein and phosphorus in each of the fractions was affected by the rate of growth and by the nature of the substrate limitation. 4. The beta-fructofuranosidase activities of yeast grown under glucose limitation increased as the growth rate was lowered, but decreased at very low growth rates. The effects at low growth rates were probably due to repression of enzyme synthesis by residual glucose in the culture filtrate. The beta-fructofuranosidase activities of yeast grown under NH(4) (+) limitation were much lower than those from yeast grown under any of the conditions of glucose limitation. 5. Yeast cells grown at any of the rates under NH(4) (+) limitation were longer and thinner than those grown at the same rate under any of the conditions of glucose limitation. Mean cell volumes were dependent on growth rate but not on the nature of the substrate limitation. 6. Electron micrographs of thin sections of isolated walls showed that cells grown under NH(4) (+) limitation had a more porous structure than those from cells grown under any of the conditions of glucose limitation.
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PMID:Effect of growth rate and substrate limitation on the composition and structure of the cell wall of Saccharomyces cerevisiae. 605 21

The aim of our work is to show the importance of the role of hydrophobic bonds in maintaining Mg2+-ATPase or sucrase activity and Na+-coupled D-glucose uptake normal for the brush border of rat enterocytes. The activity of the two enzymes and the D-glucose uptake were therefore measured under the action of n-aliphatic alcohols and related to the fluidity determined by ESR. Three concentrations were used for the first eight alcohols, those of octanol being about 1500-times lower than those of methanol. For each alcohol the D-glucose uptake and the fluidity were linear functions of the logarithm of the concentration, the linear regressions being practically parallel and equidistant. The concentrations (C) of the eight alcohols inhibiting the D-glucose uptake by 80% were similar to those increasing the membrane fluidity by 3%. The linear relationship which existed in both cases between log 1/C and log P, P being octanol/water partition coefficients of the alcohols, was evidence of great sensitivity to the hydrophobic effect of the alcohols. Only the first alcohols, however, produced any notable inhibition of Mg2+-ATPase and sucrase. Hydrophobic bonds are thus shown to have little influence in maintaining the activity of Mg2+-ATPase and sucrase, but they modulate the Na+-coupled D-glucose uptake.
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PMID:Sensitivity of Na+-coupled D-glucose uptake, Mg2+-ATPase and sucrase to perturbations of the fluidity of brush-border membrane vesicles induced by n-aliphatic alcohols. 614 7

The determination of the invertase activity of intact yeast cells presents a critical point, that is, the blockage of the enzyme action at a given moment. In this paper seven blockage methods were compared: the addition of 0.010 M sodium hydroxide solution, addition of 0.010 M sodium carbonate solution, addition of 0.010 M sodium carbonate solution followed by centrifugation (9750g; 10 min), immersion of the reacting mixture in a boiling water bath, immersion of the mixture in a -15 degrees C bath, filtration through a Millipore membrane, and addition of the first Somogyi's reagent followed by immersion in a boiling water bath. Only the last two methods lead to a rapid and effective blockage of the invertase activity.
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PMID:Measurement of invertase activity of cells of Saccharomyces cerevisiae. 634 48

Antibodies directed against Streptococcus mutans GS-5 intracellular invertase and glucosyltransferase fractions capable of synthesizing primarily water-soluble or insoluble glucans were used to ultrastructurally localize the enzymes by means of the unlabeled antibody peroxidase-antiperoxidase method. This immunocytochemical procedure revealed that the intracellular invertase was associated primarily with the cytoplasmic membrane of the cariogenic organism. The glucosyltransferase complex responsible for insoluble glucan synthesis was localized as aggregates attached to the cell surface or extracellular polysaccharides of strain GS-5. In contrast, the glucosyltransferase activity synthesizing primarily water-soluble glucans was distributed uniformly over the cell surface or in association with extracellular polysaccharides. These results are discussed relative to the sucrose-metabolizing ability of Streptococcus mutans.
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PMID:Localization of Streptococcus mutans GS-5 glucosyltransferases and intracellular invertase. 645 62

The pathogenesis of diarrhea caused by rotavirus infection was studied in miniature swine piglets. The animals were inoculated orally with 2 X 10(7) plaque-forming units of porcine rotavirus (OSU strain). During the height of diarrhea, intestinal function was investigated by in vivo perfusion of a 30-cm segment of proximal jejunum and a 30-cm segment of distal ileum. Absorption of Na+ and water decreased and 3-O-methylglucose transport was markedly reduced, P less than 0.01 compared to control animals. Mucosal lactase and sucrase levels were depressed in both the jejunum and ileum, P less than 0.001. Na+,K+-ATPase activity was significantly depressed only in the ileum, P less than 0.001. These changes were associated with a marked reduction in villous height, suggesting that the diarrhea could be an osmotic diarrhea due to nutrient (carbohydrate) malabsorption. Fresh stool samples were obtained and analyzed immediately for NA+,K+, osmolarity, glucose, and lactose; the osmotic gap was also determined. Stool osmolarity continually increased from 248 +/- 20 mosm/liter prior to inoculation to 348 +/- 20 mosm/liter at 75 +/- 1 hr postinoculation (P less than 0.005); the majority of the fecal osmotic gap could be accounted for by the amount of lactose present in the stools. Stool sodium increased from 34 +/- 6 mM prior to inoculation to a maximum of 65 +/- 4 mM at 53 +/- 1 hr postinoculation, P less than 0.001. There was no significant change in potassium concentration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Pathogenesis of rotavirus-induced diarrhea. Preliminary studies in miniature swine piglet. 648 82


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