Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A technique utilizing Pregnant Mare's Serum Gonadotropin and Human Chorionic Gonadotropin treatment of hens (Gallus domesticus), followed by manual ovulation of the excised follicles, was developed to obtain a large number of mature ova. The intact ova were used to test whether acrosin, partially purified from the spermatozoa of the cock (Gallus domesticus), partially purified rabbit testicular acrosin and commercial preparations of several hydrolytic enzymes could dissolve the inner vitelline membrane. Enzymes were applied to pieces of filter paper placed on the ovum. Cock acrosin and endopeptidases such as trypsin, chymotrypsin, collagenase and elastase hydrolyzed the membrane whereas exopeptidases such as leucine aminopeptidase and carboxypeptidase A did not. Phospholipase A, sulfatase, hyaluronidase, beta-glucuronidase and rabbit testicular acrosin also failed to hydrolyze the membrane. Cock acrosin hydrolysis of the ovum surface was inhibited by soybean trypsin inhibitor. The surface of the ovum over the germinal disc region was hydrolyzed more quickly by cock acrosin than the surface over other regions of the ovum. Acrosin from cock sperm caused the release of trichloroacetic acid soluble material absorbing at 280 nm from sonicated preparations of inner vitelline membranes. Hydrolysis was greatest at pH 8.0 and was inhibited by soybean trypsin inhibitor.
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PMID:Hydrolysis of the hen egg vitelline membrane by cock sperm acrosin and other enzymes. 0 Apr 54

High concentrations of alpha-chlorohydrin were found to inhibit hyaluronidase, beta-glucuronidase, and aryl sulphatases in bull and rabbit spermatozoa, but not acrosin and neuraminidase. Preincubation of the enzyme and alpha-chlorohydrin was essential to achieve the maximum inhibition which was irreversible.
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PMID:Inhibition of bull and rabbit sperm enzymes by alpha-chlorohydrin. 125 58

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.
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PMID:Acrosomal enzymes of human spermatozoa before and after in vitro capacitation. 640 71

Ovulated opossum oocytes are surrounded by a zona pellucida, but not by cumulus cells. Opossum sperm carry at least four acrosomal hydrolases (hyaluronidase, acrosin, N-acetylhexosaminidase, and arylsulfatase); the functions of these enzymes in opossum fertilization are uncertain. To identify possible substrates for these hydrolases, the ultrastructure of opossum oocytes was examined after fixation in the presence of ruthenium red which stabilizes extracellular matrices. This oocyte is unusual in having a wide perivitelline space containing a highly structured extracellular matrix (ECM). The ECM is comprised of granules and filaments, and it resembles matrices known to contain hyaluronic acid in other systems. Hydrolases, known to be present in opossum acrosomes, were tested for their effect on the ultrastructure of the zona pellucida and matrix of the perivitelline space. Trypsin dissolved the zona pellucida and decreased the size of the granules in the perivitelline space. Streptomyces hyaluronidase, which specifically attacks hyaluronic acid, removed only matrix filaments. Arylsulfatase, N-acetylhexosaminidase, and beta-glucuronidase did not affect the zona pellucida or ECM in our assay. These observations are consistent with the ideas that (1) opossum sperm must penetrate two oocyte investments, the zona pellucida and ECM of the perivitelline space; (2) the ECM contains hyaluronic acid (filaments) and protein (granules); (3) opossum sperm acrosin may function in penetration of the zona pellucida and ECM; and (4) opossum sperm hyaluronidase may function in penetration of the ECM by degrading hyaluronic acid (filaments). Dissolution of the granules and filaments from oocyte microvilli is probably necessary to permit close apposition and fusion of the sperm and oocyte membranes. The evolutionary significance of these results is discussed.
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PMID:Ultrastructure of opossum oocyte investing coats and their sensitivity to trypsin and hyaluronidase. 671 16

The effect of gossypol on the activities of 10 acrosomal enzymes of the rabbit sperm was evaluated. Acrosin, Azocoll proteinase, neuraminidase, and arylsulfatase were significantly inhibited or completely inactivated by 12-76 microM gossypol. Hyaluronidase, beta-glucuronidase, and acid phosphatase were inhibited only at a higher concentration of gossypol (380 microM). Phospholipase C, alkaline phosphatase, and beta-N-Acetyl glucosaminidase were not inhibited even at 380 microM gossypol. Gossypol was found to be a noncompetitive inhibitor of arylsulfatase with a Ki of 120 microM. The inhibition was reversible and dose-dependent. As the acrosomal enzymes were more sensitive to the inhibition by gossypol compared to sperm enzymes involved in glycolysis or energy production, these assays may serve as a more reliable indicator for monitoring the occurrence of gossypol-induced sterility.
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PMID:Inhibition of rabbit sperm acrosomal enzymes by gossypol. 776 16

In bacteria, the regulatory ACT domains serve as amino acid-binding sites in some feedback-regulated amino acid metabolic enzymes. We have identified a novel type of ACT domain-containing protein family in Arabidopsis whose members contain ACT domain repeats (the "ACR" protein family). There are at least eight ACR genes located on each of the five chromosomes in the Arabidopsis genome. Gene structure comparisons indicate that the ACR gene family may have arisen by gene duplications. Northern-blot analysis indicates that each member of the ACR gene family has a distinct expression pattern in various organs from 6-week-old Arabidopsis. Moreover, analyses of an ACR3 promoter-beta-glucuronidase (GUS) fusion in transgenic Arabidopsis revealed that the GUS activity formed a gradient in the developing leaves and sepals, whereas low or no GUS activity was detected in the basal regions. In 2-week-old Arabidopsis seedlings grown in tissue culture, the expression of the ACR gene family is differentially regulated by plant hormones, salt stress, cold stress, and light/dark treatment. The steady-state levels of ACR8 mRNA are dramatically increased by treatment with abscisic acid or salt. Levels of ACR3 and ACR4 mRNA are increased by treatment with benzyladenine. The amino acid sequences of Arabidopsis ACR proteins are most similar in the ACT domains to the bacterial sensor protein GlnD. The ACR proteins may function as novel regulatory or sensor proteins in plants.
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PMID:Molecular characterization of a novel gene family encoding ACT domain repeat proteins in Arabidopsis. 1248 Oct 63