Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It was previously shown that reductive alkali treatment of purified human cervical mucin releases a heterogeneous population of reduced neutral, sialylated, and sulfated oligosaccharides (Yurewicz, E. C., and Moghissi, K. S. (1981) J. Biol. Chem. 256, 11895-11904). Four major sialylated oligosaccharide fractions were isolated with approximate compositions of Fuc:GlcNac:Gal:NeuAc:N-acetylgalactosaminitol (GalNAcol) = 0:0:0:1:1 (B1a), 0:0:1:1:1 (B2b), 0:1:2:1:1 (B3a), and 1:1:2:1:1 (B4a), where Fuc is fucose. They comprised roughly 3, 11, 7, and 6% of recovered oligosaccharide chains, respectively. On the basis of periodate oxidations, methylation analyses, and sequential degradations with glycosidases, the following structures were determined. (Formula: see text) Oligosaccharides 1 and 2 are characterized by the presence of N-acetylneuraminic acid in alpha 2,6-linkage to N-acetylgalactosaminitol. The remaining oligosaccharides contain N-acetylneuraminic acid in alpha 2,3-linkage to galactose residues. Oligosaccharides 3 and 4 and oligosaccharides 5 and 6 were isolated as unresolved isomeric mixtures in fractions B3a and B4a, respectively. Oligosaccharides 3 and 4 were distinguished on the basis of susceptibility to digestion with Aspergillus niger beta-galactosidase whereas oligosaccharides 5 and 6 were distinguished on the basis of differential rates of digestion with beef kidney alpha-fucosidase. The structural data indicate the presence of at least two sialyltransferases in human cervical epithelium and further suggest a potential physiologically significant competition between sialyltransferase and beta-N-acetylglucosaminyltransferase for C-6 of the N-acetylgalactosamine residue O-glycosidically linked to serine/threonine of the polypeptide core.
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PMID:Structural studies of sialylated oligosaccharides of human midcycle cervical mucin. 355 66

Nineteen hydrolytic enzymes were detected in individual adult Pergamasus longicornis (Berlese) mites--amylase, hide protease, alkali phosphatase, esterase (C4), esterase lipase (C8), lipase (C14), leucine arylamidase, valine arylamidase, cystine arylamidase, acid phosphatase, phosphoamidase, alpha-galactosidase, beta-galactosidase, beta-glucuronidase, alpha-glucosidase, beta-glucosidase, N-acetyl-beta-glucosaminidase, alpha-mannosidase, and alpha-fucosidase. All but the phosphatases were detected for the first time. Tryptic and chymotryptic activity were consistently not demonstrable. Comparisons are made with saprophagous mites. No clear enzymic specialization for predation was found.
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PMID:Digestion in the soil predatory mite Pergamasus longicornis (Berlese) (Acari: Mesostigmata: Parasitidae)--detectable hydrolases. 356 25

In human freshly prepared platelets the following lysosomal enzymes were studied: alpha-mannosidase, alpha-fucosidase, beta-galactosidase, beta-glucosidase, beta-glucuronidase, beta-N-acetylglucosaminidase and acid phosphatase. For each of the examined enzymes the conditions providing maximal activity (pH, buffer), kinetic parameters (saturating substrate concentration and Km) as well as heat stability were established. On the basis of these parameters it is suggested that many of the serum glycohydrolases may be platelet derived.
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PMID:Lysosomal enzymes in human platelets. 383 17

The role of carbohydrate in the interaction of human migration inhibitory factor (MIF) with human peripheral blood monocytes was investigated by studying the effects of different exoglycosidases on the cellular response to MIF. When monocytes were pretreated with neuraminidase, an exoglycosidase specific for sialic acid, they became unresponsive to MIF. Other glycosidases, such as beta-galactosidase and alpha-mannosidase, were inactive in this respect. The effect of neuraminidase was reversible since the response to MIF was restored to normal levels after 24 hr. In parallel studies, a glycolipid-enriched extract from U937 cells, a human macrophage-like cell line, known to enhance the monocyte response to MIF, lost this activity when treated with neuraminidase and alpha-L-fucosidase, but not with beta-galactosidase. This suggests the importance of terminal sialic acid and fucose residues for the interaction between monocyte membrane glycolipids and MIF.
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PMID:Glycolipid receptor for human migration inhibitory factor: fucose and sialic acid are important for the human monocyte response to migration inhibitory factor. 391 66

The activities of six glycosidases in a rat colorectal adenocarcinoma were measured and compared with those of normal colonic mucosa. The specific activities of beta-galactosidase (EC 3.2.1.23) and beta-glucuronidase (EC 3.2.1.31) in the adenocarcinoma were similar to those of the corresponding ones in the normal mucosa, whereas those of beta-N-acetylglucosaminidase (EC 3.2.1.30), alpha-L-fucosidase (EC 3.2.1.51), alpha-galactosidase (EC 3.2.1.22) and beta-glucosidase (EC 3.2.1.21) were reduced in the former as compared with those in the latter. In the case of alpha-L-fucosidase, two forms were newly detected in the tumor. The relative abundance of three forms of beta-N-acetylglucosaminidase was quite different between the adenocarcinoma and the normal mucosa, and the level of the intermediate form in the tumor was markedly reduced. However, thermostability and Km values of two forms A and B in the tumor were not different from those of the corresponding ones in the normal tissue.
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PMID:Alteration in glycosidases from well-differentiated colorectal adenocarcinoma of rat. 404 71

Enzymatic degradation followed by lectin application was carried out on specimens of the rabbit oviduct. The sequential application of the glycosidases (neuraminidase, alpha-L-fucosidase, beta-galactosidase and alpha-mannosidase) and lectins (peanut, winged pea, wheat germ and soybean) seem promising as an effective method for characterising, in situ, the structure of complex carbohydrate chains. The data obtained after digestion with neuraminidase and alpha-L-fucosidase indicate the presence of a continuous layer of sialoglycoconjugates and fucoglycoconjugates that completely covers the luminal surfaces of the ampulla. The different reactivity of the glycocalyx and the secretory products indicates a different chemical composition of glycoconjugates in the glycocalyx and secretions. Although it is very difficult to explain the lectin affinity and the functional significance of the positive cells, some hypotheses have been advanced.
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PMID:Characterisation in situ of the complex carbohydrates in rabbit oviduct using digestion with glycosidases followed by lectin binding. 407

We have employed colloidal silica (Percoll) density-gradient subcellular fractionation technique to examine the distribution of lysosomal hydrolases between intermediate vesicles (primary lysosomes) and secondary lysosomes in contact-inhibited non-proliferating vs proliferating chicken embryo fibroblasts. We find that the activities of lysosomal specific enzymes from both phases of growth are distributed within two peaks; however, the relative amounts differ markedly. In normal, non-proliferating cells approx. 60% of the total activities of cathepsin B, beta-mannosidase, alpha-fucosidase, beta-galactosidase and hexosaminidase is recovered in the heavier density fraction corresponding to secondary lysosomes, while less than 9% of the enzyme activities are recovered in the light-density peak. With transformed cells, between 16 and 22% of activity for these enzymes are recovered in the lighter density intermediate vesicle fraction, when less than 40% of the enzyme activities recovered in the heavy density fraction. beta-Glucuronidase distribution was different from that of the above enzymes. First, a more even distribution between the two lysosomal fractions was found with non-proliferating normal cells (33% in heavy-density fraction and 21% in light-density fraction), whereas more than 40% of the total enzyme activity was recovered in the lighter density fraction from transformed cells. Also, the amount of cathepsin B contained in the vesicle fractions is increased severalfold relative to that of contact-inhibited normal cells. However, the apparent differences in enzyme distribution between confluent normal and transformed cells are not found when vesicles are prepared from subconfluent, actively proliferating cultures. We have also compared the Percoll density gradient patterns of membrane vesicles from proliferating and non-proliferating human fibroblasts, since most earlier studies utilized this system. Again, we find that the majority of beta-hexosaminidase activity (41%) of contact-inhibited, confluent cells is recovered in the heavier density fraction with less than 15% in the lighter density fraction. Also, the distribution of beta-hexosaminidase between the heavy density and light density vesicle fractions is altered in homogenates from exponentially growing cells, being 22% and 26% respectively. We conclude that the distribution of lysosomal hydrolases between the two vesicle populations is growth-phase dependent and is markedly heterogeneous in proliferating cells.
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PMID:Distribution of acid hydrolases in subcellular fractions of proliferating vs non-proliferating fibroblasts. 609 Jan 91

In the newborn lamb, activities of lysosomal enzymes are lower in the duodenum and jejunum than in the ileum. In contrast, there are only minor differences, if any, in activities of lysosomal enzymes between the regions of the small intestine of 5-day-old lambs. In the duodenum, jejunum and ileum, activities of hexosaminidase, alpha-mannosidase, beta-mannosidase, alpha-L-fucosidase and phosphodiesterase are greater in newborn than in 5-day-old lambs. Only in the distal part of the small intestine are activities of beta-glucuronidase, alpha-glucosidase, alpha-galactosidase, beta-galactosidase, acid phosphatase and cathepsin B higher in the newborn than in 5-day-old lambs. Cathepsin B activity is lower in the duodenum and jejunum of the newborn than in 5-day-old lambs.
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PMID:Lysosomal enzymes in the intestine of the newborn lamb. 609 93

The following enzymes of lysosomal origin were fluorimetrically determined in maternal plasma from the second to the ninth month of pregnancy at 1-mth intervals: beta-D-N-acetylglucosaminidase (EC 3.2.1.30), beta-D-glucuronidase (EC 3.2.1.31), beta-D-glucosidase (EC 3.2.1.21), beta-D-galactosidase (EC 3.2.1.22), alpha-D-galactosidase (EC 3.2.1.23), alpha-L-fucosidase (EC 3.2.1.51) and alpha-D-mannosidase (EC 3.2.1.24) (pH 4.0). As reference microsomal alpha-D-mannosidase (pH 5.7) was also studied. Thirty-eight healthy women, aged 18-37 yr, who had a normal pregnancy followed by normal parturition, were studied. All enzymes, with the only exception of beta-D-galactosidase, showed a progressive and statistically significant increase of activity throughout pregnancy. At the end of pregnancy, the increase ranged from a maximum of 5.6-fold for beta-D-N-acetylglucosaminidase to a minimum of 0.55-fold for alpha-D-mannosidase, pH 5.7. In the case of beta-D-N-acetylglucosaminidase, the level at the fifth month of pregnancy was significantly higher than that at the third month, and from the sixth to the ninth month each level significantly differed from that of the month immediately preceding.
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PMID:Behaviour of several enzymes of lysosomal origin in human plasma during pregnancy. 609 42

Seven acid glycosidases activities have been measured in normal rat uterus during the oestrus cycle. It has been observed that alpha-fucosidase, alpha-mannosidase, beta-galactosidase, alpha-galactosidase, aryl sulfatase, acid phosphatase and hexosaminidase activities changed cyclically during the oestrus cycle. From onward oestrus to metaoestrus the enzyme activities are in their highest level, but then decline slightly towards the resting one, as the cycle progresses. It is possible that changes in glycosidases content bear a lysosomal relationship, since it is known the increase in the lysosome content of the uterus during the oestrus and metaoestrus. The increased enzyme content could be related to uterus glycoproteins secretion and degradation during the normal oestrus cycle.
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PMID:Glycosidases in the rat uterus during the oestrus cycle. 609 86


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