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)

1. Two forms, I and II, of beta-galactosidase [EC 3.2.1.23] from fowl spermatozoa were separated by Blue-Sepharose CL-6B chromatography. 2. The two forms of the enzyme yielded different pI values (4.1 and 4.7 for form I and 5.3 for form II). 3. Their gel filtration patterns were also different: form I resolved into two peaks with Mr about 65,000 and 80,000, whereas form II resolved into a single peak with an Mr of about 65,000. 4. Both forms had similar optimum pH, pH stability, thermal stability and Km values. 5. Differences between the characteristics of beta-galactosidase forms from spermatozoa and from seminal plasma suggest that the beta-galactosidases investigated in this study are spermatozoa-specific.
 ...
PMID:Properties of acid beta-galactosidase from fowl spermatozoa. 314 26

Rat spermatozoa were recovered from the caput, corpus, and cauda epididymides and assayed for glycosidase activity, total nonamino (neutral) carbohydrate, and protein content. The activities of beta-glucosidase, beta-galactosidase, beta-N-acetylglucosaminidase, and beta-N-acetylgalactosaminidase were fluorometrically assayed in spermatozoa and membrane-enriched fractions. Except for beta-glucosidase, the activities of the glycosidases based on protein content were greatest in whole sperm and membrane-enriched fractions obtained from the cauda epididymides. Based on sperm concentration, however, glycosidase activities increased proceeding from the caput to the corpus epididymides, then declined from the corpus to the cauda epididymides. Analyses of nonamino carbohydrate and protein content based on sperm number indicated regional trends similar to those of glycosidase activity. Total nonamino carbohydrate and protein content were highest in corpus sperm, and lowest in cauda sperm. These data indicate major quantitative changes in cell surface carbohydrate as spermatozoa traverse the epididymis. A positive correlation for the membrane-enriched fraction between increasing glycosidase activity and decreasing carbohydrate and protein content suggests that glycosidases may play a significant role in modifying the spermatozoon surface during epididymal transit and maturation.
 ...
PMID:Changes in rat sperm membrane glycosidase activities and carbohydrate and protein contents associated with epididymal transit. 359 43

In this work the alterations of some acrosomal enzymes and gamma-GT were studied in diseases of the male genital tract. Thirty-two patients with vascular diseases, seven with inflammatory diseases and twenty-four controls were investigated. In all patients the sperm morphology was studied and the following enzymes were assayed: beta-glucuronidase, beta-galactosidase, beta-glucosidase and gamma-GT. In all patients with vascular and inflammatory diseases we found severe hypokinesis and decreased number of spermatozoa. The activity of all four enzymes in both pathological groups was decreased in comparison with the controls, and this decrease was significant for all enzymes in males with vascular diseases and for beta-galactosidase and beta-glucosidase in cases with inflammatory diseases. Our data show that the decrease of spermatozoal count was accompanied by a decreased enzyme activity. The role of decreased sperm plasma enzyme activity, the decreased production of spermatozoa and quantitative changes in structure and acrosome enzyme content are discussed.
 ...
PMID:Enzymes and cytomorphological sperm alterations in some diseases of the male reproductive system. 613 94

The effect of in vitro capacitation (events that occur before the acrosome reaction) on the acrosomal enzymes of human spermatozoa was determined. Capacitation of human spermatozoa was assessed by their ability to penetrate denuded hamster oocytes. The activities of a number of enzymes commonly associated with the sperm acrosome, including nonzymogen acrosin, proacrosin, inhibitor-bound acrosin, hyaluronidase, acid phosphatase, beta-glucuronidase, beta-glucosidase, beta-N-acetylglucosaminidase, beta-galactosidase and beta-N-acetylgalactosaminidase were assessed. With the exception of acid phosphatase, no alteration in enzyme activity occurred after 4 h of incubating the spermatozoa under capacitation conditions although gamete fusion took place. The acid phosphatase levels decreased twofold, presumably due to the loss of seminal (prostatic acid phosphatase that loosely adheres to spermatozoa. After 8 h of capacitation, a large decrease in sperm enzyme levels took place only in the case of hyaluronidase, although small decreases were also noted in total acrosin, proacrosin and inhibited acrosin. No new electrophoretically migrating forms of acrosin were observed. Decreases in total acrosin and proacrosin, but not in inhibited acrosin, also occurred when spermatozoa were incubated under noncapacitating conditions for 8 h, indicating that capacitation may specifically cause the release of some acrosin inhibitor from human spermatozoa. It is concluded that, with the possible exception of hyaluronidase, the in vitro capacitation of human spermatozoa does not cause a major change in its acrosomal enzyme content so that these hydrolases are fully present before the acrosome reaction takes place during gamete fusion. Serum albumin appears to protect against the loss of some of these enzymes since the activity of several glycosidases was significantly reduced when the spermatozoa were incubated for 8 h in human serum albumin-free medium.
 ...
PMID:Acrosomal enzymes of human spermatozoa before and after in vitro capacitation. 640 71

The activity levels of beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase, beta-galactosidase and beta-glucosidase were fluorometrically assessed in spermatozoa, principal cells, basal cells and fibroblasts isolated from the rat epididymis by centrifugal elutriation. Among the various cell types, corpus principal cells had the highest activities for beta-N-acetylglucosaminidase, beta-N-acetylgalactosaminidase and beta-galactosidase. These enzymes characteristically react with membrane structural carbohydrates. Corpus/caput principal cell activity ratios of these glycosidases remained constant when determinations were done at an alternate pH and substrate concentration, suggesting that similar enzyme forms were present in both regions. Based on cell number and cell volume, sperm glycosidase activities generally increased from the caput to the corpus region of the epididymis, while decreasing from corpus to cauda. However, when data were expressed on the basis of cell protein, sperm glycosidase activities increased from caput to cauda. Since the total protein of sperm decreases dramatically from caput to cauda, the increase in glycosidase activity based on total protein suggests that relative to other sperm proteins, glycosidases may be selectively retained or taken up during epididymal transit. High levels of glycosidase activity associated with the corpus epididymidis may contribute to modification of sperm glycoproteins and observed increases in fertility of sperm as they emerge from this region.
 ...
PMID:Glycosidase activities in principal cells, basal cells, fibroblasts and spermatozoa isolated from the rat epididymis. 643 54

It was shown that 35.3% ejaculated rabbit spermatozoa washed from seminal plasma are capable of interacting with heterogeneous DNA. The major part (85.2%) of bound DNA was located in the post-acrosomal part of the sperm head. After incubation with plasmid pRK31acZ the spermatozoa transferred it in the oocytes during in vivo fertilization, as shown by expression of reporter gene lacZ in 19.3% of preimplantation embryos. Additional treatment of the mobile spermatozoa with DMSO and heat shock raised the efficiency of exogenous DNA incorporation in the spermatozoa, as expressed in the percentage of embryos containing bacterial beta-galactosidase (61.7%). It is proposed to use the capture of heterogeneous DNA by the spermatozoa and its transfer in the oocytes for production of transgenic animals and in studies of regulation of gene expression at the early stages of embryogenesis.
 ...
PMID:[The binding of exogenous DNA pRK31acZ by rabbit spermatozoa, its transfer to oocytes and expression in preimplantation embryos]. 747 45

This study demonstrates that beta-glucuronidase from rat preputial glands binds with high affinity to spermatozoa from the cauda epididymis. The binding was calcium-independent and was inhibited by mannose-6-phosphate, but not by other phosphorylated or non-phosphorylated sugars. Binding was also inhibited by alpha-mannosidase from Dictyostelium discoideum, an enzyme known to have mannose-6-phosphate as the ligand. From solubilized sperm membranes, a protein of > 200 kDa and one of 45 kDa, were absorbed to a column of D. discoideum enzyme and to a phosphomannan column respectively, and eluted with mannose-6-phosphate. According to histochemical observations at the light and the electron microscopic level, gold particles coated with the enzyme became bound to the external surface of the plasmalemma in the acrosomal region of caudal spermatozoa. Similar labelling was observed using gold particles coated with antibodies against the rat 300 kDa phosphomannosyl receptor. The existence of phosphomannosyl receptors on the sperm plasma membrane, and our previous demonstration of the presence of affinity sites for epididymal beta-galactosidase on these gametes which is inhibited by phosphofructosyl derivatives, suggest strongly that maturing spermatozoa could be a target for glycosidases secreted into the lumen of the cauda epididymis, which then become bound to these cells via different ligand-receptor systems.
 ...
PMID:Phosphomannosyl receptors on the surface of spermatozoa from the cauda epididymis of the rat. 755 73

Components of the mammalian sperm acrosome that have been conserved during evolution are probably essential for fertilization and are therefore potential antigens for the development of an immunocontraceptive vaccine. In order to identify such protein components, a series of specific polyclonal antisera were generated by immunizing rabbits with purified acrosomal membrane fractions from hamster epididymal spermatozoa. Antisera were finally selected using immunological and in-vitro fertilization assays, and used to then screen a human testis lambda gt11 cDNA library. As a result of this screening over 70 clones were identified, selected and purified. The cDNAs were amplified by polymerase chain reaction (PCR) and the inserts characterized by restriction enzyme digestion and oligonucleotide probing techniques. The functional activity beta-galactosidase fusion proteins expressed by these clones (HA5-2, HA6-2 and HB4-1) inhibited significantly fertilization and reduced spermatozoa binding compared to controls. To date, sequence data has been obtained from HB4-1 (1.75 kb). The first 1132 nucleotides displayed > 96% homology to human testis-specific lactate dehydrogenase (LDH-C4) gene, the product of which is a known candidate antigen for a contraceptive vaccine. This finding suggests that a strategy involving the screening across species for conserved moieties of the mammalian acrosome may be useful for identifying candidate antigens for immunocontraception.
 ...
PMID:A strategy for identifying candidate sperm antigens for immunocontraception: isolation of human testis cDNA clones using polyclonal antisera directed against hamster acrosomal membrane preparation. 755 86

Pig zona pellucida (ZP) contains three families of glycoproteins: PZP2, PZP3 alpha and PZP3 beta. PZP3 alpha mediates the binding of the ZP to spermatozoa. In this study, the binding site of pig ZP on boar spermatozoa and the zona-binding proteins of boar spermatozoa were studied using chemically modified zona glycoproteins or anti-pig ZP antiserum. Endo-beta-galactosidase-digested PZP3 alpha (E beta G-PZP3 alpha), which is deficient in sulfated N-acetylpolyactosamine, as well as solubilized ZP, bound to the acrosomal region of acrosome-damaged or partially acrosome-reacted spermatozoa. However, they did not bind to acrosome-intact or fully acrosome-reacted spermatozoa. Solubilized ZP did bind to the acrosomal cap released upon acrosome reaction. In western blot analyses, E beta G-PZP3 alpha bound to the sperm proteins with molecular masses similar to proacrosin-acrosin and the binding was inhibited by fucoidan and anti-pig acrosin antiserum. These results suggest that the binding site of solubilized pig ZP and E beta G-PZP3 alpha on spermatozoa is located mainly in the acrosomal matrix and on the membranous compartments in the acrosome and suggest that E beta G-PZP3 alpha binds to proacrosin-acrosin. The binding of E beta G-PZP3 alpha to proacrosin-acrosin may be involved in the binding of the ZP to the acrosome of partially acrosome-reacted spermatozoa.
 ...
PMID:Binding of pig sperm receptor in the zona pellucida to the boar sperm acrosome. 770 84

An antiserum, designated R4 and raised against denatured hamster acrosomes, was shown to localize specifically to the acrosomal region of hamster, rat, mouse, and human spermatozoa, and to inhibit both hamster and human sperm-oocyte binding in vitro. Following screening of a human testis lambda gt11 cDNA expression library with the antiserum R4, a series of cDNA clones were isolated. One (cDNA 134) was selected based on the ability of the beta-galactosidase fusion protein to inhibit human and hamster sperm-zona binding in vitro. The fusion protein was also shown to inhibit the penetration of zona-free hamster oocytes by human spermatozoa. Sequence analysis revealed that cDNA 134 coded for a portion of a serine protease inhibitor (serpin) closely related to plasma Protein C inhibitor. Sequencing of an additional cDNA clone (261) and Northern blot analysis confirmed that a Protein C inhibitor-like mRNA is synthesised in the human testis. Affinity-purified anti-134 antibody specifically localized to the acrosomal region of both hamster and human sperm. Synthetic peptides corresponding to the conserved core region responsible for the interaction of the serpin with its cognate protease also blocked human sperm-zona binding in vitro. The results suggest that this acrosomally located inhibitor plays an important role in the series of binding events that results in human fertilization.
 ...
PMID:Human sperm-egg binding is inhibited by peptides corresponding to core region of an acrosomal serine protease inhibitor. 847 Dec 50


<< Previous 1 2 3 4 Next >>