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

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Query: EC:3.2.1.21 (beta-glucosidase)
3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The carbohydrase activities of homogenates of mucosa from the abomasum, small intestine, caecum and colon, and of the pancreas of cattle were studied. 2. The disaccharidase activities were located mainly in the small intestine and showed a non-uniform pattern of distribution along the small intestine; trehalase activity was highest in the proximal part, lactase and cellobiase activities were highest in the proximal and middle parts and maltase activity was highest in the distal part. 3. The intestinal lactase and cellobiase activities were highest in the young calf and decreased with age, whereas the intestinal maltase and trehalase activities, which were very low compared with the lactase activity, did not change with age. 4. No intestinal sucrase or palatinase activity was detected in the calf or in the adult cow. 5. Homogenates of intestinal mucosa also exhibited amylase and dextranase activity. 6. Homogenates of the pancreas possessed a strong amylase activity and a weak maltase activity. The maltase activity did not change with age, whereas the amylase activity increased with age. 7. No marked differences were observed between the carbohydrase activities of calves fed solely on milk and those of calves given a concentrate-hay diet from 6 weeks of age.
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PMID:Carbohydrase activities in the bovine digestive tract. 567 28

Brock, Thomas D. (Indiana University, Bloomington). Biochemical and cellular changes occurring during conjugation in Hansenula wingei. J. Bacteriol. 90:1019-1025. 1954.-A technique has been devised for deagglutinating mixed populations of conjugating cells so as to be able to visualize microscopically early stages of the conjugation process. A cell can form a conjugation tube only when in contact with a cell of opposite mating type, but may do so even if the mate is unresponsive or ultraviolet-inactivated. Cell fusion occurs, however, only when both cells are able to form conjugation tubes in a region of contact. Fusion begins almost as soon as the two cells begin to form protuberances, and long before any dissolution of cell-wall material between the cells occurs. A cell which has conjugated in one region of its cell wall is still able to conjugate with another cell in another region, so that triply and quadruply conjugated cells are occasionally formed. There is no significant net increase in deoxyribonucleic acid, ribonucleic acid, protein, or carbohydrate which might be related to the conjugation process, because any minor changes that occur in these components are also detected when cells of only one mating type are incubated or when the conjugation process is inhibited with the antibiotic cycloheximide. Changes in activity of beta-1,3-glucanase (with laminarin as substrate) and beta-1,6-glucanase (with pustulan as substrate) have been measured during the conjugation process, in addition to changes in the activity of several control enzymes which would not be expected to be related to the conjugation process. Significant increases in invertase (sucrase), laminarinase, and pustulanase were detected, and minimal increases occurred in beta-glucosidase and acid phosphatase. However, these same increases were also observed in controls involving only one mating type; thus, these increases are probably not related to the conjugation process, but may be a result of other processes which probably occur during incubation in the conjugation medium.
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PMID:Biochemical and cellular changes occuring during conjugation in Hansenula wingei. 584 91

1. The disaccharidases, cellobiase, isomaltase, lactase, maltase, sucrase and trehalase were investigated for presence in the camel (Camelus dromedarius) intestine and pancreas. All, except sucrase, were present. 2. Their levels of activities were measured at different positions of the small and large intestines and the location of maximum level of activity for each enzymes along the intestinal tract was established. 3. High levels of activities were determined in the contents of the intestinal lumen and, therefore, it is absorbed into the cells of the epithelial villi and hydrolyzed there. 4. The possibility of carbohydrate digestion in camel intestine is discussed.
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PMID:The level and distribution of disaccharidases in the camel (Camelus dromedarius) intestine. 612 46

The development of small intestinal enzymes (lactase, acid- and hetero beta-galactosidases, cellobiase, maltase, trehalase, and sucrase) was studied from 18 days after conception until birth in 24 rabbit fetuses, and during the postnatal period in 15 newborn, juvenile, and adult rabbits. Lactase, acid- and hetero beta-galactosidases, cellobiase, and trehalase activities increased significantly during the fetal stage, while changes in sucrase and maltase activities were not substantial. In the postnatal period, lactase and cellobiase activities decreased significantly whereas maltase, sucrase, and trehalase activities increased significantly to reach adult values by 30 days of age. The acid- and hetero beta-galactosidases remained unchanged.
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PMID:The fetal and postnatal development of small intestinal disaccharidases in the rabbit. 643 Nov 90

The activities of various glycosidases in homogenates of the small intestinal mucosa of two adult and 18 suckling tammar wallabies (M. eugenii) aged from 6 to 50 weeks were investigated. Lactase (beta-D-galactosidase), beta-N-acetylglucosaminidase, alpha-L-fucosidase and neuraminidase activities were high during the first 34 weeks post partum and then declined to very low levels. Maltase, isomaltase, sucrase and trehalase activities were very low or absent during the first 34 weeks, and then increased. The lactase activity was unusual in being greater in the distal than the middle or proximal thirds of the intestine, and in its low pH optimum (pH 4.6), inhibition by p-chloromercuribenzene sulfonate but not by Tris, and lack of cellobiase activity. These properties are those of a lysosomal acid beta-galactosidase rather than of a brush border neutral lactase. The maltase activity had the characteristics of a lysosomal acid alpha-glucosidase early in lactation and of a brush border neutral maltase in adult animals. The significance of these findings is discussed in relation to changes in dietary carbohydrates during weaning and to the mode of digestion of milk carbohydrates by the pouch young.
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PMID:Intestinal lactase (beta-galactosidase) and other glycosidase activities in suckling and adult tammar wallabies (Macropus eugenii). 678 21

The effects of oat saponins (a mixture of avenacosides A and B) and dietary fibre (cellulose and guar gum) on the disaccharidase activities in the proximal small intestine of the rat were investigated. The influence of avenacosides A and B on the activity of disaccharidases and alpha-amylase (EC 3.2.1.1) was also studied in vitro. In vivo, oat diets with three avenacoside contents (negligible, normal and twice normal) were used. No significant differences in sucrase (EC 3.2.1.48), maltase (EC 3.2.1.20), trehalase (EC 3.2.1.28) and lactase (EC 3.2.1.21) activities were found between the oat groups after 19 d feeding. The rats that were given cellulose tended to have higher disaccharidase activities compared with the other groups. The avenacosides inhibited the lactase activity significantly in vitro while no or small effects on the other disaccharidases were found. In contrast, the in vitro hydrolysis of starch by alpha-amylase was increased in the presence of saponins, probably due to their detergent effect. Thus, the in vitro studies showed that the avenacosides could influence the enzyme activities. In vivo, these effects are probably minor due to the low avenacoside concentrations found in oats.
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PMID:Effect of oat saponins and different types of dietary fibre on the digestion of carbohydrates. 754 40

Mucosal surface area, protein, DNA and RNA content, [3H]-thymidine incorporation, total activity of glucosidases, peptidases, phosphatases and transaminases were measured in the duodenum and in the middle and lower parts of the small intestine of the domestic pigeon Columba livia. Mucosal surface area, protein, nucleic acid content and [3H]-thymidine incorporation were significantly higher in the duodenum and in the middle part of the small intestine than in the lower part. Whereas the activities of alkaline phosphatase, sucrase, cellobiase and lactase were significantly higher in the middle part of the small intestine, those of maltase, glucoamylase and leucine aminopeptidase were significantly higher in the lower part. It is concluded that in Columba livia small intestine, regional differences are more pronounced between the middle and the lower parts of the small intestine than between this middle part and the duodenum.
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PMID:Regional differences along the small intestine of the pigeon (Columba livia): histobiochemical evidences. 769 Dec 16

The effect of feeding ethanol daily for 40 days was studied on various brush border enzymes in rat intestine. Brush border alkaline phosphatase (AP), lactase, gamma-glutamyltranspeptidase (gamma-GTP), p-nitrophenyl (PNP)-beta-D-galactosidase (P < 0.01) and sucrase (P < 0.001) were significantly enhanced while leucine aminopeptidase and PNP-beta-D-glucosidase activities were unaltered in ethanol fed rats compared to the controls. Kinetic studies revealed that an increase in Vmax together with a decrease in affinity in case of gamma-GTP and an increase in Vmax for AP and sucrase were responsible for the observed stimulation of enzyme activities in ethanol administered rats. Significant changes in enzyme activities were observed in different populations of enterocytes along the crypt-villus unit in the ethanol fed animals. These observations suggest that ethanol feeding modifies the brush border enzymes in rat intestine but the underlying mechanisms seem to be distinct in differentiating enterocytes.
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PMID:Expression of brush border enzymes in ethanol fed rat intestine. 782 69

Trehazolin, a new trehalase inhibitor isolated from the culture broth of Micromonospora, was reported to be a highly specific inhibitor for porcine and silk worm trehalases with IC50 values of 5.5 x 10(-9) and 3.7 x 10(-9) M, respectively (O. Ando, H. Satake, K. Itoi, A. Sato, M. Nakajima, S. Takashi, H. Haruyama, Y. Ohkuma, T. Kinoshita, and R. Enokita (1991) J. Antibiot. 44, 1165-1168). We also found that trehazolin is a very powerful and quite specific inhibitor against purified pig kidney trehalase, giving an IC50 value of 1.9 x 10(-8) M. Lineweaver-Burk plots showed that this compound was a competitive inhibitor of the trehalase. However, even at concentrations of 200 micrograms/ml, trehazolin did not inhibit the rat intestinal maltase or sucrase, yeast alpha-glucosidase or almond beta-glucosidase. Validoxylamine A and validamycin A, two other trehalase inhibitors, showed potent competitive inhibition against purified pig kidney trehalase, with IC50 values of 2.4 x 10(-9) and 2.5 x 10(-4) M, respectively. On the other hand, validoxylamine A was almost inactive against rat intestinal sucrase and maltase, with some inhibition being observed at millimolar concentration. A number of other glucosidase inhibitors, such as MDL 25637, castanospermine, and deoxynojirimycin were also tested against the purified trehalase and showed reasonable inhibitory activity.
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PMID:Inhibitors of pig kidney trehalase. 786 39

1-Deoxynojirimycin (1) is a potent inhibitor of mammalian and rice alpha-glucosidase. Several glucosides of 1 were synthesized by use of the native and immobilized enzyme and their effect on various enzymes was investigated. Transglucosylation reactions using rice alpha-glucosidase, yeast alpha- and beta-glucosidases purified from Rhodotorula lactosa were performed with maltose or cellobiose as a glucose donor and N-(benzyloxycarbonyl)-1-deoxynojirimycin (2) as an acceptor. The transglucosylation reaction using native rice alpha-glucosidase afforded 3-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (4), 4-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (5), and 2-O-alpha-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (3) in yields of 40, 13, and 2%, respectively, after 30 min. The transglucosylation reaction using immobilized rice alpha-glucosidase was similar to that using the native enzyme. In the system using native yeast alpha-glucosidase, 3, 5, and 4 were formed in yields of 34, 13, and 6%, respectively, after 15 h. The immobilization of yeast alpha-glucosidase caused a significant decrease in transglucosylation activity. Yeast beta-glucosidase showed a high transglucosylation activity and incubation with the reaction system afforded 2-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (6) and 4-O-beta-D-glucopyranosyl-N-(benzyloxycarbonyl)-1-deoxynojirimycin (7) in yields of 69 and 3%, respectively, after 3 h. The transglucosylation reaction using immobilized yeast beta-glucosidase preferentially afforded 6 in a yield of 73% after 3 h. After removal of N-benzyloxycarbonyl group from the product glucosides, their glycosidase inhibitory activities were measured. 3-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (9) retained the potent inhibition of 1 against rat intestinal sucrase activity and was more effective than 1 against rice alpha-glucosidase. 4-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (10) retained the potency of 1 against rat intestinal sucrase and isomaltase. 2-O-alpha-D-Glucopyranosyl-1-deoxynojirimycin (8) was more effective than 1 against trehalases.
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PMID:Enzymic synthesis of alpha- and beta-D-glucosides of 1-deoxynojirimycin and their glycosidase inhibitory activities. 803 79


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