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PubMed1981

[Effect of inhibition of intestinal glucosidase on protein and energy balance in rats].

In a two-factorial balance trial two dietary protein levels of 12 and 15% the effect of a supplement of 50 mg alpha-glucosidase inhibitor (Bay g 5421) per kilogram food on nutrient digestibility, protein, and energy balance was tested in growing rats. At both protein levels the alpha-glucosidase inhibitor reduced the apparent digestibility of protein by maximal 8 and 4%, those of starch and energy only by 3 and 1%, respectively. With the low protein supply the protein and energy retention was decreased each by 13% when the inhibitor was given. On the basis of metabolizable energy, 6 and 19% less energy in form of protein and fat, respectively, have been deposited compared with the control group. These results may indicate also an effect of the glucosidase inhibitor on the intermediary metabolism.

Acarbose↗

PubMed1988

Human acid beta-glucosidase: inhibition studies using glucose analogues and pH variation to characterize the normal and Gaucher disease glycon binding sites.

Comparative kinetic studies with glycon inhibitors were used to investigate the properties of the active site of human acid beta-glucosidase (EC 3.2.1.45) from normal placenta and spleens of type 1 Ashkenazi Jewish Gaucher disease (AJGD) patients. With the pure normal enzyme, the specificity of glycon binding was assessed with 35 glucose derivatives and epimers. Most glycons were mixed type inhibitors with a predominantly competitive nature (i.e., Kis much less than Kii) and had low apparent affinity for the enzyme (Kisapp = 20-500 mmol/l). beta-Glucose-1-phosphate was unusual, since it inhibited 4-methylumbelliferyl-beta-glucoside hydrolysis in an uncompetitive pattern (Kiapp = 0.55 mmol/l) but had no effect on glucosyl ceramide hydrolysis. C-1- (1-deoxy-1-amino-beta-D-glucose) and C-3- (3-deoxy-3-amino-D-glucose) amino and C-5-imino [1-deoxynojirimycin (dNM), nojirimycin and castanospermine] substituted sugars were highly potent inhibitors with Kisapp(beta-glucose)/Kisapp approximately equal to 10(3)-10(5); an amine at C-2 did not alter Kisapp compared to beta-glucose. The variation of Kisapp with pH for the 5-imino- and 1-deoxy-1-aminoglycosides conformed to a model for the unprotonated inhibitors binding to the protonated forms (EH and EH2) of the diprotic (Vmaxapp and Vmaxapp/Kmapp) normal enzyme (pK1 = 4.7; pK2 = 6.7) with pH-independent Kisapp values of 2.9-9.0 mumol/l and 0.22 mmol/l, respectively. Several of the amine-containing inhibitors competitively protected the enzyme from inactivation by conduritol B epoxide, a covalent active site-directed inhibitor, indicating interaction with residues at that site. With the partially purified AJGD splenic enzymes, the results were the same except that Kisapp(AJGD)/Kisapp(normal) = 4-17 for dNM and 1-deoxy-1-amino-beta-glucose; this ratio was approximately equal to 1 with most other glycons, and particularly, nojirimycin and castanospermine. The results of these studies indicated that the glycon binding site of the normal acid beta-glucosidase contains important residues for interaction with the C-2, C-3 and C-4 hydroxyl groups of beta-glucose and a residue with pKa = 6.7 which was critical to the binding of amine-containing inhibitors and the hydrolysis of substrates. The findings were consistent with a specific alteration in or near the glycon binding site which results in the functional abnormalities of the mutant AJGD acid beta-glucosidase.

Adult↗

PubMed2006

Analysis of rice glycosyl hydrolase family 1 and expression of Os4bglu12 beta-glucosidase.

BACKGROUND: Glycosyl hydrolase family 1 (GH1) beta-glucosidases have been implicated in physiologically important processes in plants, such as response to biotic and abiotic stresses, defense against herbivores, activation of phytohormones, lignification, and cell wall remodeling. Plant GH1 beta-glucosidases are encoded by a multigene family, so we predicted the structures of the genes and the properties of their protein products, and characterized their phylogenetic relationship to other plant GH1 members, their expression and the activity of one of them, to begin to decipher their roles in rice. RESULTS: Forty GH1 genes could be identified in rice databases, including 2 possible endophyte genes, 2 likely pseudogenes, 2 gene fragments, and 34 apparently competent rice glycosidase genes. Phylogenetic analysis revealed that GH1 members with closely related sequences have similar gene structures and are often clustered together on the same chromosome. Most of the genes appear to have been derived from duplications that occurred after the divergence of rice and Arabidopsis thaliana lineages from their common ancestor, and the two plants share only 8 common gene lineages. At least 31 GH1 genes are expressed in a range of organs and stages of rice, based on the cDNA and EST sequences in public databases. The cDNA of the Os4bglu12 gene, which encodes a protein identical at 40 of 44 amino acid residues with the N-terminal sequence of a cell wall-bound enzyme previously purified from germinating rice, was isolated by RT-PCR from rice seedlings. A thioredoxin-Os4bglu12 fusion protein expressed in Escherichia coli efficiently hydrolyzed beta-(1,4)-linked oligosaccharides of 3-6 glucose residues and laminaribiose. CONCLUSION: Careful analysis of the database sequences produced more reliable rice GH1 gene structure and protein product predictions. Since most of these genes diverged after the divergence of the ancestors of rice and Arabidopsis thaliana, only a few of their functions could be implied from those of GH1 enzymes from Arabidopsis and other dicots. This implies that analysis of GH1 enzymes in monocots is necessary to understand their function in the major grain crops. To begin this analysis, Os4bglu12 beta-glucosidase was characterized and found to have high exoglucanase activity, consistent with a role in cell wall metabolism.

Evolution, Molecular↗

PubMed2006

Recombinant human acid [alpha]-glucosidase: major clinical benefits in infantile-onset Pompe disease.

BACKGROUND: Pompe disease is a progressive metabolic neuromuscular disorder resulting from deficiency of lysosomal acid alpha-glucosidase (GAA). Infantile-onset Pompe disease is characterized by cardiomyopathy, respiratory and skeletal muscle weakness, and early death. The safety and efficacy of recombinant human (rh) GAA were evaluated in 18 patients with rapidly progressing infantile-onset Pompe disease. METHODS: Patients were diagnosed at 6 months of age and younger and exhibited severe GAA deficiency and cardiomyopathy. Patients received IV infusions of rhGAA at 20 mg/kg (n = 9) or 40 mg/kg (n = 9) every other week. Analyses were performed 52 weeks after the last patient was randomized to treatment. RESULTS: All patients (100%) survived to 18 months of age. A Cox proportional hazards analysis demonstrated that treatment reduced the risk of death by 99%, reduced the risk of death or invasive ventilation by 92%, and reduced the risk of death or any type of ventilation by 88%, as compared to an untreated historical control group. There was no clear advantage of the 40-mg/kg dose with regard to efficacy. Eleven of the 18 patients experienced 164 infusion-associated reactions; all were mild or moderate in intensity. CONCLUSIONS: Recombinant human acid alpha-glucosidase is safe and effective for treatment of infantile-onset Pompe disease. Eleven patients experienced adverse events related to treatment, but none discontinued. The young age at which these patients initiated therapy may have contributed to their improved response compared to previous trials with recombinant human acid alpha-glucosidase in which patients were older.

Dose-Response Relationship, Drug↗

PubMed1994

Characterization of beta-glucosidase and beta-glucuronidase of alkalotolerant intestinal bacteria.

The number of alkalotolerant intestinal bacteria was 1% of the total flora in humans and 0.8% of those in rats. The beta-glucosidase and beta-glucuronidase activity of these intestinal bacteria was induced by elevating the pH of the medium, but the growth was not changed. The enzyme activity in a medium of pH 7 was 5- to 10-fold higher than that in a medium of pH 6. Isolated bacteria from human and rat feces were cultured in a pH 5 general anaerobic medium (GAM) broth to reach a stationary phase, then the pH of the media was changed from 5 to 8. Both beta-glucosidase and beta-glucuronidase were increased 9.2-12.1-fold. The activity of these enzymes was also increased 2-16-fold by adding substrates (p-nitrophenyl-beta-D-glucuropyranoside or p-nitrophenyl-beta-D-glucuronide). beta-Glucuronidase(s) was inhibited by saccharic acid 1,4-lactone or D-glucuronic acid. However, when lactulose was added to the medium, and then intestinal microflora were inoculated in the medium, the productivity of these enzymes dramatically decreased. We thus contend that the induction of the beta-glucosidase and beta-glucuronidase of intestinal bacteria by a high pH can cause colorectal cancer.

Adult↗

PubMed1990

L-ascorbic acid alpha-glucoside formed by regioselective transglucosylation with rat intestinal and rice seed alpha-glucosidases: its improved stability and structure determination.

The definite structure and chemical stability of a new glucoside of L-ascorbic acid (AA) which was enzymatically glucosylated with rat intestinal and rice seed alpha-glucosidases were reported. The stability of this AA derivative in water under aerobic conditions was proved by its remarkable resistance against enhanced oxidative degradation by heat, Cu2+ ion or ascorbate oxidase, and it was found to have no reducing activity toward radicals. These properties were obviously distinguishable from those of AA. This glucoside was effectively hydrolyzed by alpha-glucosidases which possessed the ability to synthesize itself, resulting in the liberation of AA activity. The conjugate was composed of equimoles of AA and glucose. Nuclear magnetic resonance spectra, mass spectra, pH profiles of ultraviolet spectra and pK(a) value of 3.10 supported the coupling of alpha-glucose to the 2-position of AA. From these results, its structure was assigned 2-O-alpha-D-glucopyranosyl-L-ascorbic acid, being distinct from 6-O-alpha-D-glucopyranosyl-L-ascorbic acid formed with Aspergillus niger alpha-glucosidase. These findings indicate that the 2-O-glucoside formed by regioselective transglucosylation withstands oxidative degradation even in aqueous solutions and it can be used as an available active AA source for multicomponent liquid products.

Animals↗

PubMed1996

Purification and characterization of beta-D-glucosidase (beta-D-fucosidase) from Bifidobacterium breve clb acclimated to cellobiose.

The beta-D-glucosidase (EC. 3.2.1.21) activity of Bifidobacterium breve 203 was increased by acclimation with cellobiose, and the enzyme was purified to homogeneity from cell-free extracts of an acclimatized strain of B. breve clb, by ammonium sulfate fractionation and column chromatographies of anion-exchange, gel filtration, Gigapaite, and hydrophobic interaction. This enzyme had not only beta-D-glucosidase activity but also beta-D-fucosidase activity, which is specific to Bifidobacteria in intestinal flora. The molecular weight of the purified enzyme was estimated to be 47,000-48,000 and the enzyme was assumed to be a monomeric protein. The optimum pH and temperature of the enzyme were around 5.5 and 45 degrees C, respectively. The enzyme was stable up to 40 degrees C and between pH 5 and 8. The isoelectric point of the enzyme was 4.3 and the Km values for p-nitrophenyl-beta-D-glucoside and p-nitrophenyl-beta-D-fucoside were 1.3 mM and 0.7 mM, respectively. This enzyme had also transferase activity for the beta-D-fucosyl group but not for the beta-D-glucosyl group. The N-terminal amino acid sequence of this enzyme was similar to those of beta-D-glucosidase from other bacteria, actinomycetes, and plants.

Adult↗

PubMed2000

The primary structure of the subunit in Bacillus thermoamyloliquefaciens KP1071 molecular weight 540,000 homohexameric alpha-glucosidase II belonging to the glycosyl hydrolase family 31.

The gene that coded for the subunit of an molecular weight (Mr) 540,000 homohexameric alpha-glucosidase II (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) produced by Bacillus thermoamyloliquefaciens KP1071 (FERM-P8477) growing at 30 to 66 degrees C was expressed in Escherichia coli HB101. The resulting homohexameric enzyme had a half-life of 10 min at 80 degrees C. Its purification and characterization showed that the enzyme was identical with the native one except for the latter deleting 7 N-terminal residues found in the former. The primary sequence of the subunit with 787 residues and an Mr of 91,070 deduced from the gene was 24-34% identical to the corresponding sequences of 15 alpha-glucosidases in the glycosyl hydrolase family 31 from 14 eukaryotic origins and the archaeon Sulfolobus solfataricus 98/2. From the sequence analysis by the neural network method of Rost and Sander [Rost, B. and Sander, C., Proteins: Struct. Funct. Genet., 19, 55-72 (1994)], we inferred that alpha-glucosidase II might make each subunit of 3 secondary structural regions, i.e., one N-terminal beta region, one central alpha/beta region with two catalytic residues Asp407 and Asp484, and one C-terminal beta region.

Amino Acid Sequence↗

PubMed2000

Synthesis of alpha-D-glucosylglycerol by alpha-glucosidase and some of its characteristics.

It has been found that alpha-D-glucosylglycerol (GG) is contained in such traditional Japanese foods brewed by using koji as sake, miso and mirin, and that GG is formed by transglucosylation to glycerol that is produced by yeast with alpha-glucosidase (EC 3.2.1.20) from koji in the sake mash. GG has also been found to consist of three components, 2-O-alpha-D-glucosylglycerol (GG-II), (2R)-1-O-alpha-D-glucosylglycerol (R-GG-I) and (2S)-1-O-alpha-D-glucosylglycerol (S-GG-I). GG was synthesized from a mixture of maltose and glycerol by the batch method, using alpha-glucosidase (transglucosidase L-AMANO). alpha-Glucosidase seemed to be so stable that the amount of GG increased about 5-fold compared with that in the first reaction by the daily addition of maltose for 10 d. Syrupy GG obtained was found to have the following characteristics: about 0.55-fold sweetness compared with sucrose, high thermo-stability, low heat-colorability, low Maillard reactivity, low hygroscopicity, high water-holding capacity, non-cariogenicity and low digestibility.

Animals↗

PubMed2005

Effects of fermentation temperature on the content and composition of isoflavones and beta-glucosidase activity in sufu.

Sufu is a popular fermented tofu product in China. The low quality of sufu produced in the hot summer is a big problem in sufu manufacture, so we prepared sufu at two different temperatures, 26 degrees C as normal and 32 degrees C as high temperature, and the effects of temperature on isoflavones and beta-glucosidase activity were investigated. Fermentation temperature did not cause significant differences in the recovery of isoflavones, but resulted in a different redistribution of isoflavone isomers in sufu. Sufu fermented at 26 degrees C was richer in isoflavone aglycones than at 32 degrees C; the enrichment of isoflavone aglycones might have the advantage of enhancing the physiological function. No 6''-O-malonyl-glucosides were detected in sufu fermented at 26 degrees C, whereas some 6''-O-malonyl-glucosides were found at 32 degrees C. A fermentation temperature of 26 degrees C benefited the beta-glucosidase production by fungi, which contributed to valid conversion from beta-glucosides to aglycones. It was also found that beta-glucosidase converted beta-glucosides more effectively than 6''-O-malonyl-glucosides and 6''-O-acetyl-glucosides into aglycones.

Fermentation↗

PubMed2004

Properties of a recombinant beta-glucosidase from polycentric anaerobic fungus Orpinomyces PC-2 and its application for cellulose hydrolysis.

A beta-glucosidase (BglA, EC 3.2.1.21) gene from the polycentric anaerobic fungus Orpinomyces PC-2 was cloned and sequenced. The enzyme containing 657 amino acid residues was homologous to certain animal, plant, and bacterial beta-glucosidases but lacked significant similarity to those from aerobic fungi. Neither cellulose- nor protein-binding domains were found in BglA. When expressed in Saccharomyces cerevisiae, the enzyme was secreted in two forms with masses of about 110 kDa and also found in two forms associated with the yeast cells. Km and Vmax values of the secreted BglA were 0.762 mM and 8.20 micromol/(min x mg), respectively, with p-nitrophenyl-beta-D-glucopyranoside (pNPG) as the substrate and 0.310 mM and 6.45 micromol/(min.mg), respectively, for the hydrolysis of cellobiose. Glucose competitively inhibited the hydrolysis of pNPG with a Ki of 3.6 mM. Beta-glucosidase significantly enhanced the conversion of cellulosic materials into glucose by Trichoderma reesei cellulase preparations, demonstrating its potential for use in biofuel and feedstock chemical production.

Amino Acid Sequence↗

PubMed2004

Effects of sugar inhibition on cellulases and beta-glucosidase during enzymatic hydrolysis of softwood substrates.

A quantitative approach was taken to determine the inhibition effects of glucose and other sugar monomers during cellulase and beta-Glucosidase hydrolysis of two types of cellulosic material: Avicel and acetic acid-pretreated softwood. The increased glucose content in the hydrolysate resulted in a dramatic increase in the degrees of inhibition on both beta-Glucosidase and cellulase activities. Supplementation of mannose, xylose, and galactose during cellobiose hydrolysis did not show any inhibitory effects on beta-Glucosidase activity. However, these sugars were shown to have significant inhibitory effects on cellulase activity during cellulose hydrolysis. Our study suggests that high-substrate consistency hydrolysis with supplementation of hemicellulose is likely to be a practical solution to minimizing end-product inhibition effects while producing hydrolysate with high glucose concentration.

Acetic Acid↗

PubMed2006

Chemo-enzymatic production of fuel ethanol from cellulosic materials utilizing yeast expressing beta-glucosidases.

Ethanol was produced in a considerably high yield by fermenting hydrolyzates from cellulosic materials by means of a recombinant laboratory yeast expressing beta-glucosidases. Tissue paper, cotton, and sawdust were hydrolyzed by two-step sulfuric acid hydrolysis to give mixtures containing glucose, cellobiose, and higher cello-oligosaccharides. After the cellulosic material was partially hydrolyzed with 80% sulfuric acid, the hydrolysis was continued with 5% sulfuric acid. Except for non-carbohydrate components, all constituents in the hydrolyzates were fermented by the yeast that was preincubated in the medium that the plasmid encoded by the beta-glucosidases gene was kept in the multiplicated yeast. A solution containing 4% hydrolyzates from paper was fermented to give as high as 1.9% maximum ethanol concentration and 70% ethanol conversion. Cotton also gave a similar result. Sawdust was converted into ethanol in approx 22% conversion. Accordingly, it was revealed that the beta-glucosidases-expressing yeast can ferment the cello-oligosaccharides obtained by hydrolysis of cellulosic materials into ethanol. In addition, a hydrolyzate containing a high glucose proportion gave a high ethanol concentration in a short time.

Aspergillus↗

PubMed1994

Study of the role of epididymal alpha-glucosidase in the fertility of male rats by the administration of the enzyme inhibitor castanospermine.

The activity of epididymal alpha-glucosidase in adult rats was rapidly suppressed to histochemically undetectable levels within 2 days by the continuous release of the enzyme inhibitor castanospermine via a peritoneal osmotic pump at a rate of 100-200 nmol h-1. It was established that mating activities overnight depleted 72% of the spermatozoa in the distal cauda, which was replenished in 2 days, and that fertility began to decline 3 weeks after efferent duct ligation. Male rats of proven mating proficiency and fertility were treated with castanospermine, or buffered saline as control, for up to 30 days and enzyme inhibition was confirmed at the end of treatment by histochemistry. Fertility was normal at the first mating test on day 7, significantly decreased at the second mating on day 9, but recovered in a stepwise manner at subsequent matings on days 12 and 14. Delaying the third mating until day 25 did not sustain the transient subfertility. However, prolonging sperm storage in the distal cauda epididymides and preventing replenishment with freshly matured spermatozoa, by efferent duct ligation for 14 days performed on day 15 during castanospermine administration, caused a decrease in fertility and a change in the kinematics of epididymal spermatozoa of the castanospermine-treated group. In control rats, binding of epididymal spermatozoa to Vicia faba, a lectin specific for glucose and glucosamine, and mannose and mannosamine residues, decreased from the proximal caput to the distal corpus coincident with the increase in alpha-glucosidase activity on the epithelial brush border. Lectin binding then increased in the cauda where enzyme activity was absent. However, castanospermine treatment did not significantly alter this binding profile. The findings suggest that epididymal alpha-glucosidase does not play a crucial role in the development of sperm fertilizing capacity, but may be involved in the preparation of spermatozoa for storage.

Animals↗

PubMed1995

The pseudotetrasaccharide acarbose inhibits pancreatic islet glucan-1,4-alpha-glucosidase activity in parallel with a suppressive action on glucose-induced insulin release.

The pseudotetrasaccharide acarbose, previously known as a potent inhibitor of intestinal alpha-glucoside hydrolases, was investigated with regard to its influence on islet lysosomal enzyme activities and the insulin secretory processes. We observed that acarbose was a potent inhibitor of mouse islet lysosomal acid glucan-1,4-alpha-glucosidase activity, EC50 approximately 5 mumol/l, as well as of acid alpha-glucosidase activity. In contrast, acarbose did not influence other lysosomal enzyme activities such as acid phosphatase and N-acetyl-beta-D-glucosaminidase. Neutral alpha-glucosidase (endoplasmic reticulum) was only moderately inhibited in homogenate and was unaffected in intact islets. Incubation of isolated mouse islets with acarbose revealed that the pseudotetrasaccharide was a strong inhibitor of glucose-induced insulin secretion, EC50 approximately 500 nmol/l, and a significant inhibition was already observed at a concentration of acarbose as low as 100 nmol/l. The acarbose analogue maltotetrose did not influence either glucose-induced insulin release or islet lysosomal enzyme activities. Further, acarbose as well as two other alpha-glucoside hydrolase inhibitors, the deoxynojirimycin derivatives miglitol and emiglitate, did not affect islet glucose oxidation at low or high glucose levels. Acarbose also inhibited insulin release induced by the sulfonylurea glibenclamide, whereas insulin secretion stimulated by the cholinergic muscarinic agonist carbachol or the phosphodiesterase inhibitor isobutylmethylxanthine was unaffected by the drug. Moreover, complementary in vivo experiments showed that pretreatment of mice with acarbose to allow for endocytosis of the compound markedly suppressed the insulin secretory response to an intravenous glucose load.(ABSTRACT TRUNCATED AT 250 WORDS)

Acarbose↗

PubMed1998

Effect of acarbose (alpha-glucosidase inhibitor) on disaccharase activity in small intestine in KK-Ay and ddY mice.

The hypoglycemic effect and the alpha-glucosidase activity inhibition of acarbose (AC:alpha-glucosidase inhibitor) were investigated in normal and KK-Ay mice, an animal model of noninsulin-dependent diabetes mellitus (NIDDM). AC improved hyperglycemia after an oral administration of maltose or sucrose, dose dependently in normal mice (1, 10, and 50mg/kg body weight) and in KK-Ay mice (50mg/kg). Furthermore, AC (50mg/kg) significantly inhibited maltase and sucrase activities in the small intestines of normal and KK-Ay mice (inhibitory efficacy: sucrase > maltase). The enzymatic inhibition in KK-Ay mice is stronger than in normal mice. However, AC (50 mg/kg) did not suppress the blood glucose in oral lactose tolerance and did not inhibit the lactase activity in either normal or KK-Ay mice. These findings indicate that the AC effect on the inhibition of alpha-glucosidase activity is selective for sucrase and maltase in normal and NIDDM mice.

Acarbose↗

PubMed2006

Inhibition of alpha-glucosidase and alpha-amylase by flavonoids.

The inhibitory activity of six groups of flavonoids against yeast and rat small intestinal alpha-glucosidases and porcine pancreatic alpha-amylase was compared, and chemical structures of flavonoids responsible for the inhibitory activity were evaluated. Yeast alpha-glucosidase was potently inhibited by the anthocyanidin, isoflavone and flavonol groups with the IC50 values less than 15 microM. The following structures enhanced the inhibitory activity: the unsaturated C ring, 3-OH, 4-CO, the linkage of the B ring at the 3 position, and the hydroxyl substitution on the B ring. Rat small intestinal alpha-glucosidase was weakly inhibited by many flavonoids, and slightly by the anthocyanidin and isoflavone groups. 3-OH and the hydroxyl substitution on the B ring increased the inhibitory activity. In porcine pancreatic alpha-amylase, luteolin, myricetin and quercetin were potent inhibitors with the IC50 values less than 500 microM. The 2,3-double bond, 5-OH, the linkage of the B ring at the 3 position, and the hydroxyl substitution on the B ring enhanced the inhibitory activity, while 3-OH reduced it.

Animals↗

PubMed2000

Cyclo(dehydroala-L-Leu), an alpha-glucosidase inhibitor from Penicillium sp. F70614.

A diketopiperazine (1) has been isolated from the culture broth of Penicillium sp. F70614 and its structure has been determined to be cyclo(dehydroala-L-Leu) by various spectroscopic analyses. This compound selectively inhibited yeast alpha-glucosidase and porcine intestinal alpha-glucosidase with IC50 values of 35 and 50 microg/ml, respectively. However, it did not show significant inhibitory effects against almond beta3-glucosidase, Aspergillus alpha-galactosidase, Escherichia coli beta-galactosidase and jack bean alpha-mannosidase.

Binding, Competitive↗