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Enzyme
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Query: EC:3.2.1.23 (
beta-galactosidase
)
14,648
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The expression of
alpha-galactosidase
in liver, heart, and brain during postembryonic development has been examined in several inbred mouse strains. In most strains, the developmental patterns of
alpha-galactosidase
are coordinate with those of two other acid hydrolases, beta-glucuronidase and
beta-galactosidase
. Certain inbred mouse strains, including members of the C57-C58 family, have a tissue-specific alteration in the temporal expression of
alpha-galactosidase
activity. This alteration shows additive inheritance and appears to be controlled by a single genetic locus. The altered developmental expression of the enzyme is not accompanied by any discernible change in its physical properties.
...
PMID:Genetic determination of the alpha-galactosidase developmental program in mice. 21 4
9 patients with chronic pyelonephritis were given gentamicin intramuscularly in an appropriate dosage for a period of 10 days. The urinary excretion of cells, protein, alanine aminopeptidase (EC 3.4.11.2),N-acetylglucosaminidase(EC 3.2.1.30) and
alpha-galactosidase
(
EC 3.2.1.23
) was determined daily. The most striking enzyme increase occurred in alanine aminopeptidase. The enzyme and protein output appears to be rhythmic and discontinuous. A 2--3-day rhythm is suggested. Rhythmic alterations of the digestion activity of the lysosomes are assumed to be the cause of these changes.
...
PMID:[Urinary excretion kinetics of enzymes and proteins in the application of therapeutic doses of gentamycin]. 21 28
Eschscholtzia californica stigmas with germinating pollen at different stages of development were the subject of histochemical studies which aimed the localization of several enzymes like phosphorylase, leucine amino peptidase, nonspecific esterase, cytochrome oxidase, aldolase, alpha-glycerophosphate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, monoamine oxidase,
alpha-galactosidase
, beta-glucosidase and
beta-galactosidase
. Pollen and pollen tubes were shown to contain starch, lipid, proteins and soluble sugars as the storage products. These storage products were utilized during germination and tube growth. The role of different enzymes in the process of germination and tube growth is discussed. From the distribution of oxidoreductases it is inferred that respiration plays an essential role in the tube growth. During pollen germination probably the reserve proteins were transported to pollen tube tip. The increase of activity of alpha-and
beta-galactosidase
in pollen tubes indicates on their involvement in carbohydrate metabolism. The role of
alpha-galactosidase
in the metabolism of galactolipids is also inferred. Similarly, the reaction catalysed by beta-glucosidase resulted in the production of aglycon and glucose; of these the former possibly act as a substrate of peroxidase. Some of the glycosidases diffused out of pollen wall on the stigma and participated in the release of free sugars of the female tissue.
...
PMID:Studies on the physiology of pollen and pollen tube growth. IV Eschscholtzia californica Cham. 22 Jan 58
The yeast alpha-mannosidase [EC 3.2.1.24] was purified 1160-fold from the crude extract of the autolysate. The purified preparation was practically free from alpha-glucosidase, beta-glucosidase,
alpha-galactosidase
,
beta-galactosidase
, beta-mannosidase, and beta-N-acetylhexosaminidase activities. After the separation of yeast mannan during the purification procedures the enzyme became unstable but could be stored at 5 degrees C for three weeks with 50% loss of activity. The purified enzyme hydrolyzed both aryl and alkyl mannosides, but hydrolysis of yeast mannan proceeded slowly. Yeast mannan and Zn2+ increased the enzyme catalyzed hydrolysis of p-nitrophenyl mannoside, whereas NaN3, monoiodoacetate and methyl alpha-D-mannoside acted as inhibitors. The molecular weight was estimated to be 450,000 by gel filtration.
...
PMID:Purification and properties of alpha-mannosidase from bakers' yeast. 33 3
Heterozygote detection for angiokeratoma corporis diffusum (Anderson-Fabry disease, ACD), an X-linked disorder of glycosphingolipid metabolism was examined using
alpha-galactosidase
activity, an
alpha-galactosidase
/
beta-galactosidase
activity ratios (alpha/beta ratio) in leucocytes, plasma, and hair follicles; For leucocytes, 22 obligate heterozygotes, 25 suspected heterozygotes, and 47 control subjects were studied, while for plasma, the groups were 17 obligate heterozygotes and 35 controls. The alpha/beta ratio in plasma and leucocytes was clearly a better discriminator between obligate heterozygotes and controls than
alpha-galactosidase
activity alone, but still failed to detect 3 obligates with leucocytes and 2 with plasma. Discrimination was not improved by joint use of plasma and leucocyte alpha/beta ratios, but was improved by measurement of hair-follicle alpha/beta ratios. The interdecile range of log (
alpha-galactosidase
/
beta-galactosidase
activity) in 20 hair follicles from each of 4 obligate and 7 suspected heterozygotes was clearly different from 11 control subjects. Accordingly, for rapid screening for carriers of ACD, we recommend use of leucocyte or plasma alpha/beta ratios which should detect greater than 85% of heterozygotes. When results are equivocal, and ancillary information suggests heterozygous status, the more time-consuming measurement of hair-follicle alpha/beta ratios is a useful additional test.
...
PMID:Heterozygote detection in angiokeratoma corporis diffusum (Anderson-Fabry disease). Studies on plasma, leucocytes, and hair follicles. 40 11
B and T lymphocytes were separated by means of the spontaneous sheep red blood cell rosette formation technique from 3 normal donors. The following acid hydrolases were biochemically determined on separated B and T lymphocytes: acid phosphatase, beta-glucuronidase,
beta-galactosidase
, beta-hexosaminidase, alpha-arabinosidase,
alpha-galactosidase
, alpha-mannosidase, alpha-glucosidase, and pH 4.0 and pH 5.0 beta-glucosidase. The activities of most of the acid hydrolases including acid phosphatase and beta-glucuronidase were found to be slightly decreased in B lymphocytes when compared to T lymphocytes. However, alpha-mannosidase activity was found to be significantly higher in the B lymphocytes than in the T lymphocytes and offers the possibility of using this enzyme as a B lymphocyte marker.
...
PMID:Acid hydrolases in normal B and T blood lymphocytes. 41 51
Streptozotocin treatment (125 mg/kg) in the Chinese hamster induced hyperglycaemia, hypoinsulinaemia, hyperglucagonaemia and changes in body, liver, pancreas, stomach, kidney and adipose tissue weights. The pancreatic reserves of insulin and glucagon in the diabetic animals were low, but stomach glucagon high. These animals showed high levels of phosphoenolpyruvate carboxykinase and low levels of glucokinase, hexokinase, isocitrate dehydrogenase and malic enzyme, but normal levels of pyruvate kinase in the liver. Increases in lactate dehydrogenase subunit B and isozymes 2, 3 and 4 were also observed in the liver, but not in the epididymal fat pad, of the diabetic animals. N-Acetyl-beta-D-glucosaminidase was elevated in plasma, liver and heart, but not in the kidney of the treated animals. Renal
alpha-galactosidase
and beta-glucosidase were depressed, whereas
beta-galactosidase
and alpha-glucosidase remained essentially normal. These features indicated that there were considerable differences between the biochemical disorders associated with streptozotocin-diabetes in the Chinese hamster and the published observations in the rat.
...
PMID:Streptozotocin-induced diabetes in the Chinese hamster. Biochemical and endocrine disorders. 59 Jun 51
1. Potato lectin is a glycoprotein that contains about 47% (by weight) l-arabinose, 3% d-galactose and 11% hydroxyproline. It has a monomeric molecular weight of about 50000 and probably exists as a monomer-dimer system in aqueous solution, with the monomer predominating. It has a very high viscosity, which would indicate either that the molecule is very expanded or that it is an elongated ellipsoid. 2. After prolonged proteolytic digestion of a reduced and carboxymethylated derivative of the lectin, a glycopeptide was isolated (of mol.wt. 32000-34000) that included all the carbohydrate and hydroxyproline of the original glycoprotein but less than 30% of the total original amino acid residues. 3. The arabinose of the glycoprotein is present exclusively as the beta-arabinofuranoside and this includes those residues that are directly linked to the hydroxyproline residues of the polypeptide chain. All the arabinose of the glycoprotein is linked to the polypeptide chain through the hydroxyproline residues; the ratio of arabinose to hydroxyproline is 3.4:1. Although alpha-arabinofuranosides are known to be present in arabinans and arabinogalactans, the natural occurrence of beta-arabinofuranosides has not previously been reported. 4. Nine or ten serine residues of the polypeptide chain are substituted with single alpha-galactopyranoside residues that can be removed by the action of
alpha-galactosidase
from coffee beans but not by a
beta-galactosidase
. This is the first report of an alpha-galactoside linkage to serine. The effect of
alpha-galactosidase
is much greater on a glycopeptide from which the arabinose has been already removed, which indicates a steric hindrance of the galactosidase action by adjacent chains of arabinosides. 5. In 0.5m-NaOH (pH13.7), galactose residues were removed from the serine residues of the glycopeptide by a process of beta-elimination. This reaction took place very slowly in the intact glycopeptide but much more rapidly when the arabinofuranoside residues had been removed. This inhibitory effect of the arabinofuranoside residues on the beta-elimination reaction is likely to be due to a negative charge on the hydroxy groups of the adjacent arabinofuranoside residues, which would be ionized at this high pH value. 6. It is suggested that potato lectin may be representative of a class of soluble plant glycoproteins that would include precursors of the cell-wall glycoprotein extensin. If this is the case, extensin should also contain beta-l-arabinofuranosides linked to hydroxyproline and alpha-d-galactopyranosides linked to serine residues of the polypeptide chain.
...
PMID:Properties of potato lectin and the nature of its glycoprotein linkages. 66 30
The pH optima and apparent Km and Vmax values were determined for nine glycosidases of the retinal pigment epithelium (RPE) of the calf. In terms of micromoles of substrate cleaved per milligram protein per hour, the following relative order of enzymatic activities was observed: beta-N-acetylglucosaminidase greater than alpha-glucosidase = beta-N-acetylgalactosaminidase greater than alpha-mannosidase greater than
beta-galactosidase
greater than beta-glucosidase greater than alpha-fucosidase greater than
alpha-galactosidase
greater than beta-glucuronidase. The pH optimum of each of these enzymes was in the acidic range (below pH 6). All these findings refer to enzymatic activities of bovine RPE preparations obtained by the brushing procedure of Glocklin and Potts and washing as described by Berman and Feeney. Thus they may relate to those activities associated with particulate components of the RPE cell and not to the more soluble glycosidases. The distribution of the glycosidases between the washes of the cells and the final pellet of bovine RPE cells was examined. The activities of 10 glycosidases in the RPE of the embryonic chick were also examined. Neither beta-mannosidase nor beta-fucosidase activities could be detected in washed bovine RPE cells, although beta-mannosidase was detected in RPE of the embryonic chick. The presence of isoenzymes of beta-glucuronidase in bovine RPE was indicated. Specificity by beta-glucuronidase of bovine RPE for synthetic substrates was observed.
...
PMID:Glycosidases of the retinal pigment epithelium. 70 Sep 67
Green coffee bean
alpha-galactosidase
was found to catalyze the hydration of D-galactal and (Z)-3,7-anhydro-1,2-dideoxy-D-galacto-oct-2-enitol (D-galacto-octenitol), each a known substrate for
beta-galactosidase
. The hydration of D-galactal by the
alpha-galactosidase
in D2O yielded 2-deoxy-2(S)-D-[2-2H]galactose; the hydration of D-[2-2H]galacto-octenitol in H2O yielded 1,2-dideoxy-2(R)-D-[2-2H]galactooct-3-ulose. Thus, the enzyme protonated each substrate from beneath the plane of the ring, as assumed for alpha-D-galactosides. These results provide an unequivocal assignment of the orientation of an acidic catalytic group to the
alpha-galactosidase
reaction center. In addition, they reveal a pattern of glycal/exocyclic enitol/glycoside protonation by the enzyme that differs from the pattern reported for
beta-galactosidase
and from that reported for alpha-glucosidases. Further findings show that D-galacto-octenitol is hydrated by the coffee bean
alpha-galactosidase
to form the alpha-anomer of 1,2-dideoxy-D-galactooctulose and by Escherichia coli
beta-galactosidase
to form the beta-anomer. That each enzyme converts this enolic substrate to a product whose de novo anomeric configuration matches that formed from its D-galactosidic substrates provides new evidence for the role of protein structure in controlling the steric outcome of reactions catalyzed by these and other glycosylases. The findings are discussed in light of the concept that catalysis by glycosidases involves a "plastic" protonation phase and a "conserved" product configuration phase.
...
PMID:Stereochemistry of D-galactal and D-galacto-octenitol hydration by coffee bean alpha-galactosidase: insight into catalytic functioning of the enzyme. 130 73
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