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At least 19 recordsLinked to original sources
PubMed1983

Effect of concentrate feeding on the bovine intestinal and pancreatic carbohydrases. Evidence of induced increase in their activities.

1. The effects of concentrate feeding on the levels and pattern of distribution of carbohydrases in bovine intestine and pancreas were investigated. 2. No remarkable difference was noticed in the pattern of distribution of the carbohydrases along the bovine intestine, which was mostly confined to the proximal part of the small intestine. 3. The concentrate feeding, however, highly affected the levels of carbohydrases in the mucosa, luminal contents and the pancreas. Their levels slightly decreased in the mucosal tissue and significantly increased in the luminal contents. In the pancreas, the level of amylase decreased and that of disaccharidases increased. 4. Based on the presence of higher levels of activities of carbohydrases in the luminal contents, supported by the concentrate-induced increase in their levels, it is argued that the site of carbohydrate digestion, including disaccharides, in the small intestine, is the luminal contents.

Animals↗
PubMed1975

Carbohydrase activity in the digestive system of some teleost fishes.

The activity of carbohydrases in Puntius sophore (Ham.), Channa gachua (Ham.) and Cirrhinus mrigala (Ham.) has been studied. The carbohydrases have been found in the stomach, intestinal bulb, intestine, pyloric caeca and the hepato-pancreas. The hepatopancreas is the main site of production of these enzymes and it is in this organ and the intestine that their activity is highest. Their pH optimum lies between 5.4 and 6.4. The enzyme equipment in the teleost is adapted to their respective food and feeding habits both qualitatively and quantitatively. In Puntius (omnivorous) and Cirrhinus (herbivorous) all three carbohydrases, namely amylase (EC 3.2.1.1.), sucrase (EC 3.2.1.26.) and raffinase, while in Channa (carnivorous) only amylase and sucrase have been found to be active. In Cirrhinus mrigala, which is predominantly a herbivorous species, the concentration of carbohydrases is higher than those in the other two fishes.

Animals↗
PubMed1983

Dietary-induced rapid decrease of microvillar carbohydrase activity in rat jejunoileum.

Activities of several carbohydrases and peptidases were determined in proximal, middle, and distal thirds of the jejunoileum of female 16-wk-old rats that were fed a high-starch (70 cal%), low-fat (7 cal%) diet for 2 wk and also in rats that (after this introductory period) were fed an isocaloric low-starch (5 cal%), high-fat (73 cal%) diet for 1, 2, and 3 days. The body weight changes, food intake, amount of protein per intestinal segment, and rate of enterocyte migration were practically the same in all groups during these experimental periods. The decreased intake of starch was followed by a rapid decrease (40-80%) of carbohydrases (lactase, sucrase, maltase, and glucoamylase) within the first 24 h in total intestinal homogenates--and as studied in cryostat serial sections--in all regions of the jejunal villus-crypt columns, and mainly in proximal and middle segments. In contrast, the activities of leucylnaphthylamidase and L-phenylalanylglycine hydrolase exhibited little change except for a slight temporary decrease of activity on the 1st day in the proximal segment only (25-30%). Thus these data show that a decrease of starch content in an isocaloric diet evokes a rapid decrease in the activity of microvillar carbohydrases and that activity of these enzymes both in mature and immature enterocytes is capable of reacting to a change (decrease) of dietary carbohydrate content.

Animals↗
PubMed1990

Inhibitory effect of validamine, valienamine and valiolamine on activities of carbohydrases in rat small intestinal brush border membranes.

Three pseudo-aminosugars, validamine, valienamine and valiolamine, produced by Streptomyces hygroscopicus subsp. limoneus showed potent inhibitory action on rat small intestinal carbohydrase activities such as sucrase, maltase, glucoamylase, isomaltase and trehalase activities, but negligible action on lactase activity and pancreatic alpha-amylase activity. Where inhibition was seen, kinetic analysis showed fully competitive inhibition of the carbohydrase activities by all three inhibitors. Valiolamine has more potent carbohydrase inhibitory activity than validamine or valienamine, and the apparent Ki values of valiolamine for sucrase, maltase, glucoamylase, isomaltase and trehalase activities were 3.2 x 10(-7), 2.9 x 10(-6), 1.2 x 10(-6), 9.1 x 10(-7) and 4.9 x 10(-5) M, respectively, which are 10(-5) to 10(-3) times smaller than the apparent Km values.

Animals↗
PubMed1986

Effects of hydrocortisone on carbohydrase concentrations, de novo synthesis and turnover patterns in immature rat intestine.

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.

Aging↗
PubMed1984

Adaptation of the activity of membrane carbohydrases of chick small intestine to various carbohydrates.

Adaptation changes in membrane carbohydrases and those localized in the apical glycocalyx of enterocytes have been studied in chicks under the impact of carbohydrates. The investigated enzymes were not equally adapted to the carbohydrates of various degrees of polymerization. The response character of membrane carbohydrases depends on proximo-distal localization of enzymes in the small intestine and it is not specific to carbohydrates.

Adaptation, Biological↗
PubMed1977

Scope and mechanism of carbohydrase action: stereospecific hydration of D-glucal catalyzed by alpha- and beta-glucosidase.

A unique demonstration is presented of the capacity of glycosidases to create anomeric configuration de novo. Purifed Candida tropicalis alpha-glucosidase and sweet almond beta-glucosidase have been found to attack the same substrate, D-glucal, and to convert this unusual glycosyl substrate (which lacks alpha or beta anomeric configuration) to 2-deoxy-alpha-(or beta-) D-glucose, respectively. The stereospecificity of the hydration reaction catalyzed by each enzyme in D2O was revealed by the use of high-resolution (270 MHz) 1H magnetic resonance spectroscopy. The alpha-glucosidase caused a specific axial protonation (deuteration) of D-glucal at C-2, and formation of 2-deoxy-alpha-D-[2(a)-2H]glucose. The beta-glucosidase catalyzed an oppositely directed axial protonation at C-2 and formation of 2-deoxy-beta-D-[2(e)-2H]glucose. These results are not accounted for by the generally accepted mechanisms of carbohydrase action derived from studies with glycosidically linked substrates alone. D-Glucal apparently binds to the enzymes with essentially the same overall orientation as the D-glucosyl moiety of glycosidically linked substrates (with the double bond of D-glucal lying essentially in the plane of the similarly bound D-glucosyl group). Thus, the alpha-glucosidase evidently protonates D-glucal from above the double bond and alpha-D-glucosidic substrates from below the glycosidic oxygen; beta-glucosidase apparently protonates D-glucal from below the double bond and beta-D-glucosides from above the glycosidic oxygen. A detailed mechanism is proposed for the hydration of D-glucal by each enzyme, involving an incipient glycosyl carbonium ion and assuming the presence at the active site of two carboxyl groups arranged to account for catalysis of glycosylations from glycosidically linked substrates. That D-glucal serves as a glycosyl substrate for these enzymes strongly supports the concept that glycosidases and glycosyltransferases are catalysts of glycosylation (i.e., glycosylases), since this concept does not make the usual assumption that carbohydrases are restricted to acting on substrates having a glycosidic bond and either alph- or beta-anomeric configuration.

Candida↗
PubMed1968

Carbohydrase activities in the bovine digestive tract.

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.

Abomasum↗
PubMed1991

Synthesis and accumulation of protein and carbohydrases along the rat villus column.

Enterocytes of the intestinal mucosa of infant and adult rats continuously proliferate in the crypt, mature as they migrate along the villus column, and are discharged from the villus tip. We examined the synthesis patterns of total protein, lactase-phlorizin hydrolase, sucrase-isomaltase, and maltase-glucoamylase as well as the accumulation of these enzymes in cells during migration along the villus. Labeled leucine was administered intraperitoneally to suckling and young adult rats, and radioactivity was determined in protein and digestive carbohydrase pools of developing villus cells separated sequentially from tip to base of the villus column. The developing cells were found to continuously accumulate protein and carbohydrates as they ascended the villus column. In addition, incorporation of radioactivity into total protein and carbohydrase pools occurred at generally constant rates along the length of the villus. These studies showed that the differentiated enterocyte of both infant and young adult rat intestine exhibits a pattern of continuous growth while migrating the length of the villus column and maintains synthesis of protein and digestive carbohydrates at generally constant rates during this time.

Animals↗
PubMed1985

Nature of elevated rat intestinal carbohydrase activities after high-carbohydrate diet feeding.

Adult rats that were maintained on a low-carbohydrate intake showed rapid increase in the activities of sucrase, maltase, and lactase along the length of the small intestine when they were fed a high-starch diet. In the present study, we have identified these activity increases, and showed that they reflect proportional accumulations in enzyme-protein of sucrase-isomaltase (EC 3.2.1.10, 3.2.1.48), maltase-glucoamylase (EC 3.2.1.20), and neutral lactase (EC 3.2.1.23). It was determined that each of these enzymes exists in adult rat intestine in single immunoreactive form and accounts as a group for all sucrase, cellobiase, and most maltase and lactase activities. Dietary change from low to high carbohydrate (starch) resulted in an increase in [3H]leucine accumulation in each of the enzymes, without a change in the amount of label accumulation in total intestinal proteins. The increase in label accumulation in the brush-border carbohydrase pools was matched generally by proportional elevation in the pool concentrations of sucrase-isomaltase and lactase but not maltase. These studies suggest that the elevation of intestinal carbohydrase concentrations induced by high-carbohydrate feeding may involve selective stimulation of their synthesis.

Animals↗
PubMedDate not supplied

[The dynamics of carbohydrase desorption from the surface of the intestines in fish and in their parasitizing cestodes].

Data are obtained on the fixation strength of carbohydrases on the structures of digestive-absorptive surfaces of cestodes and intestines of their fish hosts. A dependence of the parasite's digestive activity on the activity of the host's enzymes has been established. General regularities of desorption dynamics of carbohydrases in studied animals and their specific peculiarities are noted.

Animals↗
PubMedDate not supplied

[Effect of amizil on the carbohydrase activity in intact animals and animals subjected to stress exposure].

Effect of a central cholinolytic drug amizyl on the activity of some digestive enzymes involved in carbohydrate hydrolysis was studied in experiments on control rats and animals exposed to immobilization stress. The experiments showed that amizyl administration modifies the activity of carbohydrases that could affect disintegration and assimilation of carbohydrases. Preliminary administration of the drug was shown to prevent substantially the changes in the enzyme activity occurring during stress situation.

Adrenocorticotropic Hormone↗
PubMed1984

Carbohydrases and their role in the biology of pathogenic fungi.

Pathogenic fungi form different carbohydrases belonging to exo- and endo-types mostly. There is a wider range of glycanases of pathogenic and facultatively pathogenic fungi which are capable of living in the free nature. The role of carbohydrases as aggressive factors of the corresponding agents of mycotic processes is increasing under a pronounced disbalance of carbohydrates in macroorganisms.

Carbohydrate Conformation↗
PubMed1986

[A stepwise method of evaluating sugar substitutes--a preliminary study using enzymes. 3. Carbohydrases from the human jejunal mucosa].

Mixed carbohydrases from human jejunal mucosa were characterized by Michaelis constants and maximal velocities of hydrolysis of 15 disaccharides and disaccharide alcohols, mainly of the glucosylfructose series. The presumed fate of such substances after oral ingestion may be foreseen from the km and vmax data. There is principal agreement that wholesomeness in man and animals as well as energetic utilization of disaccharides and split products correlate well with the enzymological data. Therefore the metabolic fate of sugar substitutes in the human body is partially predictable from such enzymic studies.

Disaccharidases↗
PubMed1998

Characterization of antigenic epitopes in anti-ulcer pectic polysaccharides from Bupleurum falcatum L. using several carbohydrases.

A polyclonal antibody (anti-bupleuran 2IIc/PG-1-IgG) against the "ramified" region (PG-1) of an anti-ulcer pectic polysaccharide was prepared and its antigenic epitopes were analyzed by using several carbohydrases. Enzymatic removal of arabinosyl residues from PG-1 by endo-(1-->5)-alpha-L-arabinanase (from Aspergillus niger) did not reduce the binding ability of anti-bupleuran 2IIc/PG-1-IgG to PG-1. When the endo-(1-->5)-alpha-L-arabinanase-resistant fraction (EA-1) was digested with rhamnogalacturonase A (rRGase A from A. aculeatus), a high-molecular-mass fragment fraction (RA-1) and an oligosaccharide fraction (RA-3) were obtained. RA-3 contained at least four kinds of oligosaccharides liberated from the rhamnogalacturonan core. This partial removal of the rhamnogalacturonan core in EA-1 also did not reduce the binding of the antibody to the polysaccharide. Further digestion of RA-1 with exo-(1-->3)-beta-D-galactanase (from Irpex lacteus), gave a high-molecular-mass fragment (EXG-1) and a trace of oligosaccharides (EXG-3). Methylation and FABMS analyses indicated that EXG-3 contained mono- and di-galactosyl oligosaccharides possessing terminal GlcA or GlcA4Me. Removal of the EXG-3 fraction from RA-1 by exo-(1-->3)-beta-D-galactanase significantly reduced the ability of the binding of the antibody to the polysaccharide. When PG-1 was digested with endo-(1-->6)-beta-D-galactanase (from Trichoderma viride) or beta-D-glucuronidase (from A. niger), the reactivities of both enzyme-resistant fractions to the antibody were decreased in comparison with that of PG-1. Both radish arabinogalactan (containing GlcA4Me) and beta-D-GlcpA-(1-->6)-beta-D-Galp-(1-->6)-D-Galp were shown to inhibit the reactivity of PG-1 to the antibody by competitive ELISA. These results suggest that 6-linked galactosyl chains containing terminal GlcA or GlcA4Me attached to (1-->3)-beta-D-galactosyl chains, are important sugar residues in the antigenic epitopes of the "ramified" region of bupleuran 2IIc.

Bupleurum↗
PubMed2002

Carbohydrase activities of the rolC-gene transformed and non-transformed ginseng cultures.

The levels of activity of beta-D-glucosidase, alpha-D-mannosidase, alpha- and beta-D-galactosidase, 1,3-, 1,6-, 1,4-beta-D-glucanases, 1,4-alpha-D-glucanase, fucoidanhydrolase and agarase were measured in extracts of non-transgenic and transgenic Panax ginseng cultures transformed with the rolC gene. Significantly increased levels of activity of beta- and alpha-D-galactosidases and 1,3-beta-D-glucanase were detected in rolC-gene transformed cells, compared to the control non-transformed cells, while levels of activity of other enzymes were unchanged. These, as well as the gel-permeation experiments, revealed that transformation of ginseng cells by the rolC gene could significantly affect activity of some carbohydrases and production of their molecular forms.

Cells, Cultured↗
PubMed1999

In vitro effects of cadmium and DDVP (dichlorvos) on intestinal carbohydrase and protease activities in freshwater teleosts.

In vitro effects of cadmium (0.5-50 mg/l) and DDVP (0.2-100 mg/l) on the total amylolytic, sucrase and protease activities of intestinal mucosa have been studied for the first time in 11 freshwater teleosts. Total amylolytic activity in burbot, crucian carp and common carp, sucrase activity in blue bream and total proteolytic activity in burbot and pike were significantly decreased by cadmium at 50 mg/l. DDVP (at 0.2 mg/l) caused a significant decrease in total proteolytic activity in pike but had no effect on either protease or carbohydrase activities in other fish species.

Animals↗
PubMed1978

Model for carbohydrase action. Aspergillus oryzae alpha-amylase degradation of maltotriose.

Aspergillus oryzae alpha-amylase catalyzes degradation of oligosaccharides by a variety of pathways. We present here a quantitative study of the degradation of maltotriose by this amylase. Our results lead to a scheme involving multiple transglycosylation reactions and shifted binding due to simultaneous binding of two substrate molecules. The scheme is able to account for the diverse body of information collected for the enzyme. The effect of substrate concentration on the products of maltotriose degradation is correctly predicted over a 10(4)-fold concentration range, and the time course of maltotriose degradation is closely approximated by this scheme. The initial velocity data, which show deviation from Michaelis-Menton kinetics, are also consistent with the formulated scheme. The scheme is proposed as a general model of carbohydrase action.

Amylases↗