Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After a brief review of the molecular structure of cervical mucus, the data are presented on inhibition of sperm transport through cervical mucus by polyanions and on enhancement of sperm penetration in cases of infertility due to antisperm antibodies. Cervical mucus is a gel made up of large, unbranched, glycosylated glycoprotein with highly glycosylated domains separated by hydrophobic peptide chains. Spermatozoa probably traverse the unbound water phase rather than the water bound to the macromolecules. Since mucin is a polyanion, polycations were investigated as potential vaginal spermicides. The two biguanides studies, chlorhexidine and Vantocil were both spermicidal in concentrations of 1-10 mg/ml. Their rate of entry into mucin in capillary tubes differed. Vantocil penetrated superficially and set up a barrier of inspissated mucus. Chlorhexidine entered further, with dept inversely proportional to concentration. Both biguanides increased the thickness of cervical mucus in a dose-dependent manner, as judged by dynamic storage modules, by sedimentation in analytical ultracentrifugation, and by solubility in 0.22 M thiocyanate. It was speculated that these biguanides act by altering the molecular configuration of mucin. In the presence of anti-sperm antibodies, spermatozoa observed in cervical mucus in vitro may show non-progressive mobility or immobility. The presence of auto-antibodies can be shown with Immunobeads. Binding of secretory IgA to sperm can be cleaved with bacterial protease as can binding of IgG with trypsin. By assaying the blockage of sperm by antibodies with Immunobeads and measuring penetration of sperm in donor cervical mucus, displacement of sperm antibodies could be demonstrated in 9 infertile subjects. Therefore, it might be possible to treat the ejaculate with proteases, and achieve conception by either a gamete intrafallopian tube transfer or an in vitro fertilization procedure.
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PMID:Changes in cervical mucus that prevent penetration by spermatozoa. 270 82

Bovine spermatozoa were incubated in vitro with lysophosphatidylserine (LPS), lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI), or trypsin. Capacitation of sperm was evaluated by penetration of the zonae pellucidae of dead bovine oocytes. Capacitation times could be shortened to 3 h or less by treatment of spermatozoa with each of these lysophospholipids (LPLs) (P less than .05). The maximum oocyte penetration percentages for individual LPLs were 40% for 10 microM LPS. 24% for 160 microM LPC, 31% for 320 microM LPE, and 19% for 320 microM LPI. Capacitation also was facilitated (P less than .01) by trypsin treatment of spermatozoa. Spermatozoa treated with 250 or 2,500 units/ml of trypsin penetrated more oocytes (17 and 18%) than spermatozoa treated with 0 or 25 units/ml of trypsin (0 and 3%). Spermatozoa treated with increasing concentrations of LPL showed a decrease in both the percentage of intact acrosomes and of progressively motile spermatozoa. Increasing levels of trypsin in the incubation medium also led to a decrease (P less than .05) in the percentages of intact acrosomes and a decrease (P less than .01) in the percentages of progressively motile spermatozoa. Percentages of live, ovulated oocytes fertilized by spermatozoa incubated for 1 h in LPS (86%, 6/7) were not different from those incubated for 24 h in control medium (71%, 5/7). Percentages of oocytes fertilized with both of these capacitation treatments were higher (P less than .05) than for oocytes exposed or killed or uncapacitated sperm. Rapid induction of capacitation and the acrosome reaction can be accomplished by exogenous treatment of bovine sperm with lysophospholipids or trypsin.
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PMID:Capacitation of bovine spermatozoa by lysophospholipids and trypsin. 270 26

An anti-sticking factor (ASF-I) that showed high affinity for inhibiting adhesion of spermatozoa to glass was isolated from goat epididymal plasma and characterized. The factor was purified approx. 5600-fold and showed a single protein band when examined by non-denaturation and SDS-polyacrylamide gel electrophoresis. The molecular mass and S20w value of ASF-I were approx. 47 kDa and 4.25 S. ASF-I at a concentration of 1 nM showed nearly maximal anti-sticking activity when approx. 60% of the intact spermatozoa were prevented from adhesion to glass and it showed a high degree of protein specificity. Studies with trypsin and glycosidases demonstrated that both the sugar and protein parts of the molecule are essential for its anti-sticking activity. Evidence has been presented to support the view that the outer surface of sperm possesses specific ASF-I receptors that bind to 125I-labelled ASF and mediate cell adhesion to glass. ASF-I also showed high affinity for inhibiting agglutination of corpus-epididymal spermatozoa. The ASF activity was found to be distributed in all the tissues tested and its specific activity was markedly higher in blood plasma than in the tissues. The results suggest that ASF may play an important biological role by serving as a specific inhibitor of cell-substratum and cell-cell adhesions.
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PMID:Purification and characterization of an anti-sticking factor from goat epididymal plasma that inhibits sperm--glass and sperm--sperm adhesions. 271 14

Epithelial cells of the rat's epididymal caput were cultivated according to own modification of the Kierszenbaum's method [1981]. The said modification consisted in developing primary cultures of the epithelial cells in the epididymal duct by making use of small tubular segments instead of deisolated cells of the whole epididymal duct wall. Such small segments of the tubules were procured by resorting to mechanical isolation and a 4-grade enzymatic isolation with trypsin and collagenase, whereupon the produced suspension of cells and tubules was filtered through a grid, the meshes of which being 40 X 50 microns in diameter. The cultures were made up exclusively of the tubular segments that had remained on the grid. The utilized technique of isolation gets rid of tubules from the external layer of muscle cells and fibroblasts as well as spermatozoa still prior to the inception of the culture, and provides the possibility to obtain a pure population of epithelial cells. The latter cells have the capacity to migrate from tubular fragments, and to form monolayer cultures. In the conducted cultures the epithelial cells commence secreting PAS-positive substance which was evidenced by means of histochemical and microscope-electron examinations.
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PMID:Modified procedure for isolation of epithelial cells of rat epididymal caput. 280 90

Goat epididymal intact spermatozoa have been shown to possess on the external surface specific receptors that bind with high affinity to exogenous [8-3H]cyclic AMP. The ecto-cyclic AMP-receptor activity was not due to contamination of broken or "leaky" cells, if any. The binding reaction of [3H]cyclic AMP with the receptors was extremely rapid. Uptake of the labeled cyclic AMP to the sperm cytosolic fraction was undetectable. There was little leakage of cyclic AMP-receptors from intact spermatozoa during the binding assays. The binding reaction was proportional to cell concentration, specific and saturable at 250 nM cyclic AMP. The binding of the labelled cyclic nucleotide was nearly completely displaced at saturating concentrations (2.5 microM) of the unlabelled nucleotide. The ecto-receptors showed high specificity for binding to cyclic AMP. The Kd of the binding sites was approximately 1.7 X 10(-8) M. The binding interaction was highly sensitive to treatment with proteolytic enzymes: trypsin, chymotrypsin, or pronase (125 micrograms/ml). Sonication caused a nearly 450% increase of the ecto-receptor activity. The specific activity of the ecto-cyclic AMP-receptor was approximately twofold higher in the vigorously forwardly motile spermatozoa than in the "composite" cells, suggesting that the ecto-receptors may have a role in modulating flagellar motility.
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PMID:Ecto-cyclic AMP-receptor in goat epididymal intact spermatozoa and its change in activity during forward motility. 282 7

A method for estimating the concentration of spermatozoa in the rat cauda epididymidis is described. Treatment of a sperm suspension with 0.05% collagenase for 20-60 min or 0.025% trypsin for 1-2 min at 34-37 degrees C was found to result in consistently homogeneous sperm. Sperm concentration ranged from 152.5 to 230.0 X 10(7) spermatozoa/ml, with a mean of 187.7 (+/- 5.6 SEM) X 10(7) spermatozoa/ml.
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PMID:A method for estimating the concentration of spermatozoa in the rat cauda epididymidis. 283 33

Using immunoaffinity chromatography on a Sepharose 4B column with adsorbed antibodies to the basic inhibitor in bovine organs (Kunitz-type), a proteinase inhibitor was isolated from boar seminal vesicle fluid. The isolated protein inhibited acrosin, trypsin, plasmin and chymotrypsin, but not kallikrein. Its molecular weight determined by gel filtration on Sephadex G-50 was 9,500 (+/- 500) and by SDS electrophoresis in polyacrylamide gel 12,000 (+/- 500) daltons. The protein was demonstrated by immunoprecipitation only in boar seminal vesicle fluid and seminal plasma, and by indirect immunofluorescence on ejaculated spermatozoa and in the epithelium of boar seminal vesicles. This inhibitor is the first acrosin inhibitor specific for the genital organs, which evidently belongs to the group of Kunitz type inhibitors, to be described.
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PMID:A Kunitz type of proteinase inhibitor isolated from boar seminal vesicle fluid. 293 36

The effect of various proteases (kallikrein, plasmin, and trypsin) on sperm phospholipase A2 activity (PA2: EC 3.1.1.4) has been studied. The addition of trypsin to spermatozoa, isolated and washed in the presence of the protease inhibitor benzamidine, increased PA2 activity optimally with trypsin concentrations of 1.0-1.5 units/assay. In kinetic studies, all of the above proteases stimulated the deacylation of phosphatidylcholine (PC); in fresh spermatozoa, trypsin showed a higher activation potential than kallikrein or plasmin. In the presence of benzamidine, the activity remained at basal levels. Endogenous protease activity due to acrosin (control) resulted in an increase in PC deacylation compared to the basal level. The maximum activation time of PA2 activity by proteases was 30 min. Natural protease inhibitors (soybean trypsin inhibitor and aprotinin) kept the PA2 activity at basal levels and a by-product of kallikrein, bradykinin, did not significantly affect the control level. Protein extracts of fresh spermatozoa exhibited the same pattern of PA2 activation upon the addition of proteases, thus indicating that the increase in PA2 activity was not merely due to the release of the enzyme from the acrosome. All of these findings suggest the presence of a precursor form of phospholipase A2 that can be activated by endogenous proteases (acrosin) as well by exogenous proteases present in seminal plasma and in follicular fluid (plasmin, kallikrein). Thus, this interrelationship of proteases and prophospholipase A2 could activate a dormant fusogenic system: the resulting effect would lead to membrane fusion by lysolipids, key components in the acrosome reaction.
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PMID:Activation of phospholipase A2 of human spermatozoa by proteases. 297 29

Sperm antigens that appear during spermatogenesis in the baboon were identified by using three monoclonal antibodies generated in culture from mice immunized with baboon caudal epididymal spermatozoa. Antibodies BSA1 and BSA2 recognize trypsin-sensitive 84,000 and 45,000 dalton determinants that are restricted to the tail and anterior acrosomal regions of the sperm, respectively, as determined by Western blot and immunofluorescence techniques. The tail antigen absent in 2- and 3-yr-old baboon testes first appears in spermatid cells at about 4 yr of age. In contrast, the acrosomal antigen recognized by BSA2 is present in 3-yr-old primitive testicular germ cells. In the mature testis, the 45,000 molecular weight determinant is predominantly localized in the nucleus of late pachytene spermatocytes and round spermatid cells as observed via the avidinbiotin immunoperoxidase method. Antibody BSA3 reacted only with sailidase-treated sections of adult testis. This trypsin-resistant determinant, not expressed on testicular sperm, is recognized by antibody BSA3 only on epididymal sperm, thus indicating a post-testicular sperm modification.
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PMID:Characterization of baboon testicular antigens using monoclonal anti-sperm antibodies. 306 87

In this communication I have attempted to present an overview of some contributions to the understanding of the oviduct-egg interaction in amphibians. According to data from other authors, the vitelline envelope of the newly ovulated egg constitutes a barrier for the passage of spermatozoa. Our results demonstrated that only after they have been affected by substances released by the first 1-3 cm of the oviduct (pars recta), is the envelope sensitive to spermlysins and the oocytes fertilizable. This functional change is matched by biological, physicochemical and morphological differences in the vitelline envelope. The fact that the pars recta activity is affected by the sexual cycle and that in ovariectomized females - devoid of active pars recta - the biological activity can be restored by steroid hormones, strongly suggests that the molecules involved in fertilization are synthesized and secreted during specific steps of the reproductive cycle. The pars recta-oocyte interaction probably involves more than one type of molecules, considering the observations made on the carbohydrate metabolism of coelomic eggs, which could be altered by the oviducal secretions. Several explanations for the pars recta mechanism of action have been suggested. One is a direct action on the sperm; pars recta molecules - engulfed in the vitelline envelope - would trigger the acrosome reaction. We propose the unmasking of specific vitelline envelope sites for sperm interaction. Material on the outer surface of the VE can be removed or altered by the enzymatic activity - similar to plasmin and trypsin - detected in the pars recta secretions.
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PMID:Oviducal pars recta as factor in fertilization properties and hormonal regulation in the toad Bufo arenarum. 310 80


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