PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “GALACTOSIDASE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources

The cloning and characterization of alpha-galactosidase present during and following germination of tomato (Lycopersicon esculentum Mill.) seed.

alpha-Galactosidase (EC 3.2.1.22) is present in the embryo, micropylar and lateral endosperm of seeds of tomato during and following germination. Its activity is unchanged even when germination of the seeds is prevented by an osmoticum. It is also present in the developing and mature dry seed. A cDNA clone for tomato seed alpha-galactosidase (LeaGal) has been isolated and the characteristics of the protein deduced; the predicted molecular mass of the mature enzyme is 39.8 kDa, with a pI of 4.91. The tomato alpha-galactosidase has a high homology (>62%) at the amino acid level with that of other plant alpha-galactosidases. A hydrophobic signal peptide region is identified which is indicative that the enzyme enters the lumen of the endoplasmic reticulum during its translation, prior to its export to the protein body or cell wall, the presumed sites of its substrates. Using amino acid alignment and phylogenetic analysis, key amino acids have been identified, and relationships to other alpha-galactosidases inferred. Southern hybridization analyses show that the enzyme is derived from a single gene (for which a partial sequence has been obtained) and yet there are at least three different isoforms within the seed; post-translational modifications are thus presumed to occur. From Northern hybridization studies it is evident that alpha-galactosidase transcripts are present in the lateral and micropylar endosperm during and following germination, and also to a lesser extent in the embryo.

Amino Acid Sequence↗

beta-Galactosidases with a lectin-like domain are expressed in strawberry.

Strawberry fruits (Fragaria x ananassa Duch.) undergo a marked softening during their ripening, and the process is accompanied by a release of free sugars with galactose among them. In this work total beta-galactosidase activity was measured in cell wall proteins from strawberry fruits at different developmental stages. Three full-length cDNAs (Fa beta gal1, Fa beta gal2 and Fa beta gal3, respectively) encoding different beta-galactosidases (EC 3.2.1.23) were isolated from a library representing red fruit transcripts. All of them could be detected both in fruits and in vegetative tissues. However, only Fa beta gal1 showed an increasing expression during the ripening stages up to a maximum in the red fruits, while the other two (Fa beta gal2 and Fa beta gal3) were mostly found in green fruits and became barely detectable during ripening proper. The three beta-galactosidase-encoding cDNAs were expressed in the yeast Pichia pastoris, and it was thus possible to demonstrate that each of them encode a beta-galactosidase. The expression of the three beta-galactosidase genes appears to be down-regulated by auxin, as already observed for other ripening-related genes of the non-climacteric strawberry. An unusual characteristic of two strawberry beta-galactosidases (Fa beta gal1 and Fa beta gal2) is that at the C-terminus of the enzymes a domain is found which is structurally related to known animal peptides with a sugar-binding ability.

Amino Acid Sequence↗

Beta-Galactosidase messenger RNA made during recovery from inhibition of protein synthesis is not translated.

Bacteria that accumulate RNA in the course of inhibition of protein synthesis are impaired in their ability to synthesize beta-galactosidase during subsequent recovery. By contrast, constitutive enzyme synthesis in recovering cells is normal. Even though no beta-galactosidase is made during recovery from this inhibition, a substantial quantity of beta-galactosidase mRNA (as determined by DNA-RNA hybridization) is made. The beta-galactosidase mRNA made in vivo is functional in vitro. It is capable of directing the in vitro synthesis of a portion of the NH2-terminal beta-galactosidase molecule (in the alpha portion of the molecule). However, this protein is not made in vitro. It is concluded that the beta-galactosidase mRNA that is made during recovery from protein synthesis inhibition, although apparently at least partly normally transcribed in vivo and functional in vitro cannot be translated under these conditions in vivo.

Chloramphenicol↗

A highly reactive beta-galactosidase (Escherichia coli) resulting from a substitution of an aspartic acid for Gly-794.

The beta-galactosidases of several mutagenized strains of Escherichia coli K12 which grew on lactobionate were found to be heat labile. Sequence analysis of the lacZ gene (ligated into Bluescript) of one of these strains (E. coli REH4) showed that the only change in the amino acid sequence was a substitution of an Asp for Gly-794. This change caused a dramatic increase of the activity when lactose was the substrate. The kcat of the purified enzyme from E. coli REH4 (G794D-beta-galactosidase) with lactose as the substrate was five to six times as large as the kcat of the normal enzyme with lactose. Purified G794D-beta-galactosidase was, however, less stable to heat and also to chymotrypsin (which cleaves next to Trp-585) than was normal beta-galactosidase. G794D-beta-Galactosidase bound substrates and substrate analog inhibitors less well than did normal beta-galactosidase while planar transition state analog inhibitors were more strongly bound. The ability to bind 2-amino-D-galactose (a positively charged transition state analog inhibitor) was either unaltered or was decreased somewhat. The data showed that the alteration in structure caused an increase in the value of k2 (the rate constant for the step in which the glycosidic bond is cleaved) with each substrate tested (the increase was at least 25-fold when lactose was the substrate) while k3 was decreased about 4-fold (k3 is the rate constant for the common hydrolysis step with each substrate). Since k2 is rate determining when lactose is the substrate of the normal enzyme, the increase in k2 resulted in a large increase in rate despite the fact that the value of k3 decreased. Large rate increases were not found with the other two substrates because the k2 values were not increased by large factors and because the decrease in the value of k3 negated the effects of the increased k2 values. The destabilization of the substrate binding coupled with a stabilization of the binding of a planar transition state is a possible cause of the significant increase in the value of k2 and of the enhanced activity with lactose.

Aspartic Acid↗

Proteolysis of fusion proteins: stabilization and destabilization of staphylococcal protein A and Escherichia coli beta-galactosidase.

The product yield of staphylococcal Protein A reached only 1.8% of the cell dry weight, while the corresponding value was 14% for a fusion protein composed of Protein A and Escherichia coli beta-galactosidase [1], when produced in the same E. coli host strain, with the same promoter and under identical process conditions. Measurement of the stability of Protein A in vivo showed that it was quickly degraded in the cell with a half-life of 30 min when the protein was expressed alone, but after fusion to beta-galactosidase, the Protein A part became considerably stabilized. In spite of the fast intracellular proteolysis of Protein A, few degradation products could be identified on Coomassie Brilliant Blue-stained SDS/PAGE gels after IgG purification, indicating an even faster degradation of the Protein A fragments. Such degradation products, however, accumulated during incubation of the disintegrated cells. Intracellular degradation intermediates could be demonstrated with the more sensitive Western-blot technique. This technique also revealed that a slow degradation took place not only in the Protein A moiety of the fusion protein, but also in the beta-galactosidase moiety. A control with native beta-galactosidase also showed a weak in vivo proteolysis of this molecule, but it was more stable in free form than in the fused form. This means that the proteolytically very sensitive Protein A was stabilized by fusion with beta-galactosidase, but the originally rather stable beta-galactosidase became slightly more susceptible to proteolysis after the fusion.

Amino Acid Sequence↗

Lactosylceramide beta-galactosidase in human sphingolipidoses. Evidence for two genetically distinct enzymes.

In view of recent conflicting reports from two laboratories, activities of lactosylceramide beta-galactosidase were reinvestigated in detail in brains and livers of normal individuals and of patients with globoid cell leukodystrophy or GM1-gangliosidosis. Both sets of the apparently totally contradictory results were readily reproduced simply by using the different assay systems of the respective laboratories. With our own assay system, hepatic lactosylceramide beta-galactosidase appeared deficient only in Gm1-gangliosidosis, while it appeared deficient only in globoid cell leukodystrophy when the assay system of Wenger et al. (Wenger, D.A., Sattler, M., Clark, D., and McKelvey, H. (1974) Clin. Chim. Acta 56, 199-206) was used. Analyses of individual constitutents in the two assay systems revealed their complex effects on measured activities of the enzyme. The findings were strongly indicative of the existence of two genetically distinct lactosylceramide-cleaving enzymes. One enzyme (lactosylceramidase I) may be identical with galactosylceramide betal-galactosidase, and the other (lactosylceramidase II) is closely related to nonspecific 4-methylumbelliferyl beta-galactosidase. Normal human brain contains mostly lactosylceramidase I, while normal liver contains predominantly lactosylceramidase II. Lactosylceramidase I is genetically lacking globoid cell leukodystrophy, and lactosylceramidase II in GM1-gangliosidosis. Lactosylceramidase I is activated by either pure or crude taurocholate and by oleic acid and is only slightly activated by chloride ions. Lactosylceramidase II is activated by crude taurocholate but not by pure taurocholate. As activators, oleic acid is less effective and chloride more effective than for lactosylceramidase I. Citrate-phosphate buffer is more favorable to lactosylceramidase I than citrate buffer, while lactosylceramidase II responds in reverse. The standard assay system used by Wenger et al. determines almost exclusively lactosylceramidase I, while our own standard system is optimal for lactosylceramidase II and is less favorable for lactosylceramidase I. With a highly purified human hepatic beta-galactosidase preparation, exxentially free of galactosylceramide beta-galactosidase activity, lactosylceramide-cleaving activity determined by the Wenger system was less than 2 per cent of that determined by our system. If lactosylceramide beta-balactosidase assays are to be used for diagnosis of globoid cell leukodystrophy, it is absolutely essential to use an appropriate assay system in order to avoid errors of serious consequences.

Brain↗

Characterization of recombinant Autographa californica nuclear polyhedrosis virus (NPV) expressing the beta-galactosidase gene in both Sf21 and Bm5 cells by Bombyx mori NPV p143 helicase gene.

Genomic DNA of recombinant AcNPV expressing beta-galactosidase was cotransfected with p143 helicase gene of BmNPV into Sf21 cells. Ac-Bm hybrid viruses capable of replicating in both Bm5 and Sf21 cells were isolated. Ac-Bm hybrid viruses expressing beta-galactosidase either at the highest (Ac-Bm hybrid virus-HE) or lowest (Ac-Bm hybrid virus-LE) level were chosen for the characterization of beta-galactosidase expression in Bm5 and Sf21 cells. Expression level of beta-galactosidase and replication of Ac-Bm hybrid virus-HE in Sf21 cells were nearly identical to those of recombinant AcNPV. Furthermore, replication of Ac-Bm hybrid virus-HE in Bm5 cells was similar to that of wild-type BmNPV, and Ac-Bm hybrid virus-HE clearly expressed beta-galactosidase in Bm5 cells. However, expression of beta-galactosidase by Ac-Bm hybrid virus-HE in Bm5 cells was significantly lower than that expressed in Sf21 cells. The titer of Ac-Bm hybrid virus-HE determined by plaque assays in Bm5 cells was similar to that determined in Sf21 cells, but the plaque size formed by Ac-Bm hybrid virus-HE in Bm5 cells was apparently smaller than that formed in Sf21 cells. In addition, expression levels and virus titers of Ac-Bm hybrid virus-LE in Sf21 and Bm5 were significantly lower than those of Ac-Bm hybrid virus-HE. Therefore, DNA sequences were determined for the region of the p143 gene controlling the host range in Ac-Bm hybrid viruses. The results showed that the deduced amino acid sequences of Ac-Bm hybrid virus-HE were almost identical to those of BmNPV. There were differences only in amino acids at positions 461 and 470, whereas those of Ac-Bm hybrid virus-LE were different at position 461, 470, 514, and 528 from those of BmNPV. In conclusion, our results clearly demonstrated that Ac-Bm hybrid virus-HE has an additional advantage of expanded host range for producing recombinant proteins.

Amino Acid Sequence↗

Effect of colostrinin, an immunomodulatory proline-rich polypeptide from ovine colostrum, on sialidase and beta-galactosidase activities in murine thymocytes.

Colostrinin: a proline-rich polypeptide (PRP) from ovine colostrum and its nonapeptide active fragment (NP) induce maturation and differentiation of murine thymocytes, formation of helper cells from PNAhigh thymocytes and cytotoxic T cells from PNAlow thymocytes. These processes are accompanied by changes in expression of receptors for peanut agglutinin (PNA), PNAhigh thymocytes were transformed into PNAlow cells, and vice versa. It was shown, in various laboratories, that sialyltransferases are involved in the transformation of PNAhigh thymocytes into PNAlow cells. To find out whether the expression of receptors for PNA on murine thymocytes might also be influenced by other enzymes, we decided to study the effect of PRP and NP on sialidase and beta-galactosidase activities in these cells. The results obtained showed that the most of sialidase activity of murine thymocytes is present in the plasma membrane compartments. Both thymocyte subpopulations PNAhigh and PNAlow, showed similar sialidase activity, which was not affected either by PRP or NP. In contrast to sialidases, most of beta-galactosidase activity was present in the cytosol. PNAhigh, thymocytes showed a higher beta-galactosidase activity than PNAlow cells. Incubation of immature, PNAhigh, thymocytes with PRP or NP enhanced the beta-galactosidase activity in these cells. The presented results suggest that sialidases seem not to be involved in modulation of surface sialic acid content during murine thymocyte maturation. On the other hand, stimulation of activity of beta-galactosidase in PNAhigh, immature thymocytes by PRP and NP suggests that beta-galactosidase in murine thymocytes might be involved in transformation of PNAhigh into PNAlow cells.

Adjuvants, Immunologic↗

Beta-galactosidase histochemistry and telomere loss in senescent retinal pigment epithelial cells.

PURPOSE: To investigate the relation of senescence-related beta-galactosidase activity and telomere shortening to replicative senescence in cultured human retinal pigment epithelial (RPE) cells. METHODS: A human RPE cell line was serially passaged until 80% of cells were nondividing in a 72-hour 5-bromo-2'-deoxyuridine (BrdU) labeling study. Early- and late-passage cells were double-stained for BrdU and senescence-related beta-galactosidase activity (pH 6). The average chromosomal telomere length at several population doublings was estimated by Southern blot analysis after double digestion of DNA with RsaI and HinfI and using a telomere-specific probe. RESULTS: BrdU-beta-galactosidase double-staining revealed an inverse correlation between the number of BrdU-labeled nuclei and beta-galactosidase-labeled cells as a function of population doubling level (PDL). At PDL 58, only 20% of all cells labeled for BrdU, whereas 57% stained for beta-galactosidase. The mean terminal restriction fragment length (TRF) was reduced from 10 kb in early (PDL 12) cultures to 4 kb in late (PDL 57) cultures. CONCLUSIONS: Senescence-related beta-galactosidase activity and mean TRF length may prove useful in studying the senescence of RPE cells in vitro. These techniques may be valuable in determining senescence of the retinal pigment epithelium in vivo, where senescent RPE cells could be involved in the development of age-related maculopathy and age-related macular degeneration.

Blotting, Southern↗

Synthesis of 5-amino-5-deoxy-D-galactopyranose and 1,5-dideoxy-1,5-imino-D-galactitol, and their inhibition of alpha- and beta-D-galactosidases.

A 12-step route is presented starting from 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose for the preparation of the title compounds and their L-altro analogues. Their synthesis is based on the reduction with Raney nickel of a protected 5-hydroxyimino derivative of L-arabino-hexofuranos-5-ulose, with the following improvements for the preparation of a D-galactofuranose derivative: oxidation at C-3 with pyridinium dichromate-acetic anhydride, stereospecific reduction of a 3-O-acetyl-hex-3-enofuranose intermediate to the D-gulo derivative, and inversion at C-3 of its 3-tosylate with tetrabutylammonium acetate in chlorobenzene. alpha-D-Galactosidase from coffee beans and from Escherichia coli and beta-D-galactosidase from E. coli and Aspergillus wentii were inhibited with Ki values that ranged from 0.0007 to 8.2 microM. Formation of the enzyme-inhibitor complexes with the D-galactose analogue was on the time-scale of minutes, whereas the D-galactitol analogue showed a slow approach to the inhibition only with alpha-D-galactosidase from coffee beans and beta-D-galactosidase from A. wentii. N-Alkylation of the D-galactitol analogue was detrimental to the inhibition except for beta-D-galactosidase from E. coli and beta-D-glucosidase from almonds, but, even with these enzymes, the observed affinity enhancements were 10(2) to 10(3)-times smaller than those of N-alkylated D-galactosylamine and D-glucosylamine.

Aspergillus↗

Molecular cloning and high-level expression in Escherichia coli of fungal alpha-galactosidase from Absidia corymbifera IFO 8084.

A cDNA encoding the alpha-galactosidase of Absidia corymbifera IFO 8084 was cloned and sequenced. The cloned DNA has a single open-reading frame consisting of 2190 base pairs, and the deduced amino acid sequence revealed that the mature enzyme consisted of 730 amino acid residues with a molecular mass of 82,712 Da. The native structure of the alpha-galactosidase of A. corymbifera IFO 8084 was determined to be a tetramer. Comparison with amino acid sequences of other alpha-galactosidase showed high homology with sequences of members of family 36. An expression vector, pET32Trx/galalpha, was constructed by introducing the cDNA coding region into a thioredoxin fusion system, pET32-Ek/LIC. The resulting transformant, pET32Trx/galalpha, overproduced the active enzyme as a thioredoxin fused form in the host Escherichia coli. By using His-binding metal affinity chromatography, recombinant alpha-galactosidase was purified to homogeneity in a single step. The purified recombinant fusion alpha-galactosidase showed properties very similar to the native alpha-galactosidase from A. corymbifera IFO 8084.

Journal Article↗

Host-Pathogen Interactions: I. A Correlation Between alpha-Galactosidase Production and Virulence.

Resistance or susceptibility of Red Kidney, Pinto and Small White beans (Phaseolus vulgaris) to the alpha, beta, and gamma strains of Colletotrichum lindemuthianum was either confirmed or established. These fungal strains secrete alpha-galactosidase, beta-galactosidase and beta-xylosidase when grown on cell walls isolated from the hypocotyls of any of the above bean varieties. These enzymes effectively degrade cell walls isolated from susceptible 5-day old hypocotyls but degrade only slightly the walls isolated from resistant 18-day old hypocotyls. The amounts of the beta-galactosidase and beta-xylosidase secreted by the 3 fungal strains are relatively low and are approximately equivalent. The secretion of these 2 enzymes is not dependent upon the bean variety from which the hypocotyl cell walls used as a carbon source were isolated. However, the fungal strains secrete greater amounts of alpha-galactosidase when grown on hypocotyl cell walls isolated from susceptible plants than when grown on walls from resistant plants. Virulent isolates of the fungus, when grown on hypocotyl cell walls isolated from a susceptible plant, secrete more alpha-galactosidase than do attenuated (avirulent) isolates of the same fungal strain grown under the same conditions. The alpha-galactosidase secreted by each of the fungal strains is capable of removing galactose from the hypocotyl cell walls of each bean variety tested. Galactose is removed from the cell walls of each variety at the same rate regardless of whether the cell walls were isolated from a susceptible or resistant plant.

Journal Article↗

beta-Galactosidases in Ripening Tomatoes.

Tomatoes (Lycopersicon esculentum L.) contained a high level of beta-galactosidase activity which was due to three forms of the enzyme. During tomato ripening, the sum of their activities remained relatively constant, but the levels of the individual forms of beta-galactosidase changed markedly. The three enzymes were separated by a combination of chromatography of DEAE-Sephadex A-50 and Sephadex G-100. During ripening of tomatoes, beta-galactosidases I and III levels decreased but the beta-galactosidase II level increased more than 3-fold. The three enzymes were optimally active near pH 4, and all were inhibited by galactose and galactonolactone. However, the enzymes differed in molecular weight, K(m) value with p-nitrophenyl-beta-galactoside, and stability with respect to pH and temperature. beta-Galactosidase II was the only enzyme capable of hydrolyzing a polysaccharide that was isolated from tomatoes and that consisted primarily of beta-1, 4-linked galactose. The ability of beta-galactosidase II to degrade the galactan and the increase in its activity during tomato ripening suggest a possible role for this enzyme in tomato softening.

Journal Article↗

Influence of Storage at Freezing and Subsequent Refrigeration Temperatures on beta-Galactosidase Activity of Lactobacillus acidophilus.

The ability of three strains of Lactobacillus acidophilus to survive and retain beta-galactosidase activity during storage in liquid nitrogen at -196 degrees C and during subsequent storage in milk at 5 degrees C was tested. The level of beta-galactosidase activity varied among the three strains (0.048 to 0.177 U/10 organisms). Freezing and storage at -196 degrees C had much less adverse influence on viability and activity of the enzyme than did storage in milk at 5 degrees C. The strains varied in the extent of the losses of viability and beta-galactosidase activity during both types of storage. There was not a significant interaction between storage at -196 degrees C and subsequent storage at 5 degrees C. The strains that exhibited the greatest losses of beta-galactosidase activity during storage in milk at 5 degrees C also exhibited the greatest losses in viability at 5 degrees C. However, the losses in viability were of much greater magnitude than were the losses of enzymatic activity. This indicates that some cells of L. acidophilus which failed to form colonies on the enumeration medium still possessed beta-galactosidase activity. Cultures of L. acidophilus to be used as dietary adjuncts to improve lactose utilization in humans should be carefully selected to ensure that adequate beta-galactosidase activity is provided.

Journal Article↗

Immobilization of beta-galactosidase, albumin, and gamma-globulin on epoxy-activated acrylic beads.

A comparative study was conducted into the immobilization of beta-galactosidase, albumin, and gamma-globulin on an epoxy-activated polyacrylic matrix (oxirane C, Röhm-Pharma GmbH, Darmstadt). The kinetic parameters of the immobilized beta-galactosidase were investigated with three kinds of miniaturized analytical reactors; namely, stirred batch, continuous stirred-tank, and packed-bed reactors. The optimum binding conditions, saturation activity and Michaelis constant of immobilized beta-galactosidase are given, together with determinations of the binding capacity of the oxirane C matrix for the three proteins investigated. For beta-galactosidase a saturation activity of 1300 U/g oxirane C was reached. The maximum binding, achieved by experiment, was 140 mg/g with 0.69 yield for albumin, 120 mg/g with 0.61 yield for gamma-globulin, and 40 mg/g with 0.42 yield for beta-galactosidase. From these data the inner surface of the matrix as a function of the size of the bound proteins was estimated.

Acrylates↗

Fused lacZ genes code for di-, tri- and tetra-beta-galactosidase in Escherichia coli.

Plasmids were constructed which carry two, three or four active lacZ genes of Escherichia coli fused head-to-tail in phase. The products of these oligomeric lacZ genes are shown to be polypeptides with expected subunit mol. wts. of 230 kd (di-beta-galactosidase), 350 kd (tri-beta-galactosidase) and 460 kd (tetra-beta-galactosidase). Di-beta-galactosidase has the same enzymatic activity as the wild-type enzyme. It subunits are practically not degraded proteolytically in vivo. It aggregates predominantly to a dimer which has the same sedimentation constant as the wild-type tetrameric enzyme. Furthermore, it is more heat stable than the wild-type enzyme. Tri- and tetra-beta-galactosidase have strongly reduced enzymatic activities and are largely degraded. Our experiments lead us to propose that covalent joining of two subunits through proper gene duplication may possibly be an intermediate in the evolution of self aggregation of homo-oligomeric proteins.

Electrophoresis, Polyacrylamide Gel↗

Beta-galactosidase--an indicator of the maturational stage of mouse and human mononuclear phagocytes.

Resident, elicited, and activated mouse peritoneal macrophages exhibit a differential expression of the activity of the enzyme beta-galactosidase; freshly harvested resident macrophages express a remarkably high activity whereas the latter two populations are almost void of enzymic activity. During in vitro cultivation there is an enhancement in the level of the enzyme in the three populations, and a significant proportion of both thioglycollate-elicited and Corynebacterium parvum-activated macrophages acquire beta-galactosidase activity. Cells within in vitro differentiated bone marrow-derived mononuclear phagocyte colonies are heterogeneous with respect to expression of beta-galactosidase activity. The percentage of cells expressing medium to intense enzymic activity is augmented with time in culture. Essentially the same pattern is observed in colonies differentiated from bone marrows of mice bearing acute or chronic inflammation. Freshly isolated human peripheral blood monocytes are essentially void of detectable beta-galactosidase activity. Eighty to ninety percent of the monocytes acquire medium to intense activity during a 7-day cultivation period. The data support the suggestion that beta-galactosidase expression in mononuclear phagocytes is a correlate of their maturational stage both in vivo and in vitro and does not reflect the state of elicitation or activation of these cells.

Animals↗

Localization of a gene for human alpha-galactosidase B (= n-acetyl-alpha-d-galactosaminidase) on chromosome 22.

The localization of the structural gene for human alpha-galactosidase B (= N-acetyl-alpha-galactosaminidase) was investigated by means of man-Chinese hamster and man-mouse somatic cell hybrids. The hybrid clones were analyzed for chromosomes and for a large number of known enzyme markers. The lysates of the hybrid cells were treated with Sepharose-coupled antihuman alpha-galactosidase B and the activity of the adsorbed enzyme was measured on the Sepharose beads as N-acetyl-alpha-galactosaminidase. The results show that the structural gene for human alpha-galactosidase B is situated on chromosome 22, and that there is no structural relationship between human alpha-galactosidase A and human alpha-galactosidase B.

Animals↗