Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trichosporon pullulans IGC 3488 produced extracellular alpha-amylase and glucoamylase activities when grown in batches in a medium containing corn steep liquor and soluble starch or corn starch. alpha-Amylase, unlike glucoamylase activity, was secreted biphasically. For both amylases the maximum concentration was found in stationary phase cultures. The amylolytic enzymes, previously concentrated by ammonium sulfate precipitation, were separated into a glucoamylase fraction and an alpha-amylase fraction by Ultrogel AcA 54 gel filtration. Pullulanase activity was located in the glucoamylase fraction, whereas cyclodextrinase activity was restricted to the alpha-amylase fraction. Isoamylase and alpha-glucosidase were not detected. Electrophoretic analysis showed that alpha-amylase activity was due to a single protein. Glucoamylase, however, occurred in multiple forms. The four glucoamylases and the alpha-amylase were glycoproteins.
...
PMID:Secretion of alpha-amylase and multiple forms of glucoamylase by the yeast Trichosporon pullulans. 308 51

Hydrocortisone administration to infant rats enhanced cellobiase and maltase activities and induced precocious expression of sucrase and trehalase activities along the length of the small intestine. These activity changes reflected proportional concentration increases in the enzymes lactase (EC 3.2.1.23), maltase/glucoamylase (EC 3.2.1.20) and sucrase-isomaltase (EC 3.2.1.48/10). Administration of an equivalent tracer dose of [3H]leucine (by body weight) to control and hydrocortisone-treated infant rats resulted in greater accumulation of label in the carbohydrase pools of the treated rats, suggesting their increased de novo synthesis. The increased concentrations of lactase and maltase/glucoamylase induced by exogenous hydrocortisone were matched by the presence of corresponding greater amounts of label in their brush border pools. Accumulation of label in each of the lactase, maltase/glucoamylase and sucrase-isomaltase pools was generally similar in the hydrocortisone-treated rats, suggesting equivalent stimulation of their synthesis as a group by the humoral agent. The turnover rates of the carbohydrases as a group were found to be similar and did not appear to differ in control and hydrocortisone-treated rats. Total protein synthesis rates were slightly greater in the intestine of the hydrocortisone-treated group of rats.
...
PMID:Effects of hydrocortisone on carbohydrase concentrations, de novo synthesis and turnover patterns in immature rat intestine. 308 73

Full-value diets of similar composition were given to male rats weighing 207-230 g, by intravenous (group 1) or intragastric (group 2) routes. The proportion of amino acids, fats and carbohydrates was 9.9:15.7:74.4 (with regard to their calorific value). The diet calorific value comprised 60.6 kcal/rat/day. An average mass increase in group 1 was 2.44 +/- 0.14 g/day, in group 2 - 1.75 +/- 0.11 g/day. The protein content and activities of alpha- and gamma-amylase, invertase, maltase, and glycil-L-leucine dipeptidase were assayed in the intestinal mucosa of the proximal portion of the small intestine in group 1 rats, while a decreased alpha-amylase activity in the distal portion of the small intestine was recorded in the animals of group 2. The mass of the pancreas in the rats of group 1 and 2 was authentically lower than in the control rats which received oral feeding with natural foods. The lowest mass of the pancreas was observed in the rats of group 1. Specific activity of trypsin, lipase and RNase in the pancreatic tissues of rats in groups 1 and 2 was similar. The results of the study have evidenced a lowered function of the digestive system under conditions of artificial feeding, especially in case of intravenous nutrition.
...
PMID:[Digestive function of the small intestine and pancreas in rats on artificial feeding]. 309 Jul 82

A new chromogenic substrate that is blocked at the nonreducing end, 4,6-benzylidene-alpha-D-4-nitrophenylmaltoheptaoside, is used to determine alpha-amylase (EC 3.2.1.1) activity in serum in a coupled assay with alpha-glucosidase (EC 3.2.1.20) and glucoamylase (EC 3.2.1.3) as auxiliary enzymes. The duration of the lag phase between 25 and 37 degrees C is less than 90 s, and the molar absorptivity of 4-nitrophenol is constant. The main cleavage product of the substrate by human pancreatic and salivary alpha-amylase is 4-nitrophenylmaltoside; in the presence of the auxiliary enzymes, greater than 95% of hydrolyzed substrate is accounted for as 4-nitrophenol. The combined reagent is stable for at least 20 days at 2-8 degrees C; precision is good, with CVs ranging from 1.7 to 3.3%; and the correlation of results with those by the 4-nitrophenylmaltoheptaoside method is excellent. Heparin (40 kilo-int. units/L), ascorbic acid (2.8 mmol/L), bilirubin (430 mumol/L), hemoglobin (170 mumol/L), glucose (55 mmol/L), and triglycerides (11 mmol/L) do not interfere in the assay.
...
PMID:Rapid determination of alpha-amylase activity by use of a new chromogenic substrate. 310 53

The effects of glucocorticoids (hydrocortisone, dexamethasone) and insulin on enzymatic activities of the intestinal brush border membrane were investigated in an anuran amphibian, Alytes obstetricians, before and during experimental metamorphosis produced by immersion into a thyroxine solution. During experimental metamorphosis, a new epithelium (secondary epithelium) replaces the degenerating primary epithelium. The enzymes studied were three glucidases (maltase, glucoamylase, trehalase) and alkaline phosphatase. In tadpoles reaching the end of premetamorphosis, hormones were injected every day (hydrocortisone, dexamethasone: 25 micrograms/g body wt/day; insulin: 5 mU/g body wt/day, for 3 and occasionally 6 consecutive days. Under such conditions, most of the activities in the primary epithelium increased or remained stable. In animals which completed experimental metamorphosis, the secondary epithelium formed. Hydrocortisone (25 micrograms/g body wt/day) and insulin (5 mU/g body wt/day) treatments significantly decreased the enzymatic activities of the new brush border membrane in animals which received one hydrocortisone and/or insulin injection per day, during 3 consecutive days. Such results, which previously had not been obtained systematically in spontaneously metamorphosing tadpoles (El Maraghi-Ater, Mesnard, and Hourdry (1986). Gen. Comp. Endocrinol. 61, 53-63), emphasize the relative independence of the intestinal metabolism during experimental and spontaneous metamorphosis.
...
PMID:Hormonal control of the intestinal brush border enzyme activities in developing anuran amphibians. II. Effects of glucocorticoids and insulin during experimental metamorphosis. 310 33

The chemical synthesis of swainsonine [(1S,2R,8R,8 alpha R)-trihydroxyindolizidine] from trans-1,4-dichloro-2-butene was previously described [Adams, C. E., Walker, F. J., & Sharpless, K. B. (1985) J. Org. Chem. 50, 420-424]. A modification of that synthesis provided two other isomers, referred to here as "Glc-swainsonine" [(1S,2S,8R,8 alpha R)-trihydroxyindolizidine] and "Ido-swainsonine" [(1S,2S,8S,8 alpha R)-trihydroxyindolizidine]. To determine whether these new compounds had biological activity, they were compared to swainsonine as inhibitors of a number of commercially available glycosidases. While swainsonine is a potent inhibitor of jack bean alpha-mannosidase but does not inhibit other glycosidases, its two isomers were inactive on alpha-mannosidase but did inhibit other enzymes. Thus, Glc-swainsonine was an inhibitor of the fungal alpha-glucosidase amyloglucosidase, and this inhibition was of a competitive nature (Ki = 5 X 10(-5) M) with respect to the substrate p-nitrophenyl alpha-D-glucopyranoside. This alkaloid also inhibited beta-glucosidase, but much less effectively than alpha-glucosidase. On the other hand, Ido-swainsonine was more effective toward beta-glucosidase than toward alpha-glucosidase, and this inhibition was also of a competitive nature. None of these inhibitors were effective against beta-mannosidase or alpha- or beta-galactosidase. Glc-swainsonine was also tested against the glycoprotein processing glycosidases. Surprisingly, in this respect, the alkaloid was like swainsonine in that it inhibited mannosidase II but had no effect or only slight effect on glucosidase I, glucosidase II, and mannosidase I. Glc-swainsonine also inhibited glycoprotein processing in cell culture.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Effect of isomers of swainsonine on glycosidase activity and glycoprotein processing. 311 29

Studies of intestinal enzyme development and regulation relevant to the human infant require an animal model with a rate of maturation similar to that of the human infant. Hanford miniature pigs were weaned at 3 days of age to a standard swine weaning formula. At 1, 2, 3, 4, 5, and 6 wk of age, duodenal jejunal, and ileal segments were analyzed for protein content and lactase, sucrase, maltase, glucoamylase, and acid beta-galactosidase activities. Protein content of the small intestine changed significantly with age only in the ileum (p less than 0.05). Lactase activity fell significantly with age in all segments of the small intestine (p less than 0.001); activity was highest in the jejunum. Sucrase and maltase activities were present in all segments of the small intestine at 1 wk of age. Sucrase increased significantly (2-fold, p less than 0.02) with age only in the ileum and maltase increased significantly with age in the jejunum (by 50%, p less than 0.05) and the ileum (3-fold, p less than 0.001). Activities were highest in the jejunum. Glucoamylase activity was present at 1 wk of age and showed a small but significant increase with age only in the duodenum (p less than 0.005). Acid beta-galactosidase activity demonstrated small but significant decreases with age in all small intestinal segments. Glucoamylase and acid beta-galactosidase activities were similar in all segments. In the 6-wk-old pigs, activities of all the enzymes tested were similar to those found in young human infants.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The miniature pig as an animal model for the study of intestinal enzyme development. 312 4

Two neutral alpha-glucosidase isoenzymes were isolated from the muscle of Japanese quails with late-onset acid maltase deficiency. One isoenzyme is predominantly expressed in embryonic muscle and the other in adult muscle. The time of switching from one to the other of these two neutral alpha-glucosidases was the same as in normal birds. The glycogen content in acid maltase-deficient muscle was not inversely proportional to the amount of embryonic neutral alpha-glucosidase. From the results, we conclude that (i) the transition of neutral alpha-glucosidase from the embryonic to the adult type is not influenced by the disease, and (ii) the embryonic neutral alpha-glucosidase seems not to be directly correlated with glycogen storage in skeletal muscle. In acid maltase-deficient muscle, the activity of the embryonic type began to increase again from 14 days after hatching, and attained a level corresponding to 18% of the total neutral alpha-glucosidase activity at 3 months (P less than 0.025). Its biochemical characteristics were the same as those of the normal embryonic neutral alpha-glucosidase. It should be clarified why the reappearance of the normal embryonic type occurs in acid maltase-deficient adult muscle and whether or not the reappearance of the embryonic neutral alpha-glucosidase represents regenerating muscle.
...
PMID:Reappearance of embryonic neutral alpha-glucosidase isoenzyme in acid maltase-deficient muscle of Japanese quail. 312

The effects of several hormones on intestinal brush border membrane enzymatic activities have been investigated in intestinal explants taken from the amphibian midwife toad at different developmental stages. Explants were treated for at least 2 days with thyroxine (0.1 microgram/ml of culture medium) or for 2 days with cortisol (25 micrograms/ml) or insulin (6 mU/ml). The hydrolases examined were maltase, trehalase, glucoamylase, and alkaline phosphatase. In the explants from tadpoles in prometamorphosis, thyroxine had no effect on hydrolase activities; cortisol increased the activity of only glucoamylase, and insulin increased activity of maltase, glucoamylase, and alkaline phosphatase. When the explants were taken from tadpoles at the beginning of climax, cortisol and insulin generally stimulated the enzyme activities studied. When taken from tadpoles at the end of climax, at the moment when the embryonic cells under the degenerating epithelium divide, cortisol and insulin had little effect on these activities. When the animals terminate their metamorphosis, the intestinal epithelium of the explants is totally newly formed (secondary epithelium). At this time, cortisol stimulated the activities of maltase, glucoamylase, and alkaline phosphatase, while insulin decreased the activities of maltase and glucoamylase.
...
PMID:In vitro study of the intestinal brush border enzyme activities in developing anuran amphibian: effects of thyroxine, cortisol, and insulin. 313 Apr 58

p-Nitrophenyl O-(6-O-benzyl)-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl- (1----4)-O-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl-(1-- --4)-alpha-D-glucopyranoside (BG5P) is hydrolyzed by both human salivary alpha-amylase (HSA) and human pancreatic alpha-amylase (HPA) to O-(6-O-benzyl)-alpha-D-glucopyranosyl-(1----4)-O-alpha-D-glucopyranosyl- (1----4)-alpha-D-glucopyranose (BG3) and p-nitrophenyl alpha-maltoside (G2P). Glucoamylase and alpha-glucosidase cannot hydrolyze BG5P because of the modification of the OH group of the 6-position of the non-reducing-end glucose residue with the benzyl group. Taking advantage of these characteristics of the substrate, BG5P, we developed a method to assay the total alpha-amylase activity in human fluids using glucoamylase and alpha-glucosidase as the coupled enzymes. This method is simple and can be used as the standard method for routine clinical assays of alpha-amylase activity.
...
PMID:Alpha-amylase assay with use of a benzyl derivative of p-nitrophenyl alpha-maltopentaoside, BG5P. 313 47


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---