Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The in vivo effect of purified human alpha1-antitrypsin and inter-alpha-trypsin inhibitor on the fertilizing ability of capacitated rabbit spermatozoa was investigated and compared with that of the trypsin-kallikrein inhibitor from bovine organs (Trasylol). Only 250 mug of alpha1-antitrypsin/5 X 10(4) sperm in 0.05 ml inhibited fertilization by more than 50%. Lower concentrations of alpha1-antitrypsin (50 mug/5 X 10(4) sperm in 0.05 mo) and inter-alpha-trypsin inhibitor in amounts of 250 mug/5 X 10(4) sperm and less had no significant effect on the fertilization rate. Comparative experiments with Trasylol in conentrations of 50 mug/5 X 10(4) sperm resulted in more than 50% fertilization inhibition, whereas 100 mug/5 X 10(4) sperm decreased the fertilization rate by approximately 90%. The differences in the antifertility effect of these acrosin inhibitors toward capacitated spermatozoa may be due to differences in molecular weight. The effective concentrations required for fertilization inhibition appear to be relatively high under the experimental conditions used.
...
PMID:Effect of serum proteinase inhibitors on the fertilizing capacity of rabbit spermatozoa. 108 94

The types and incidence of antisperm antibody were studied before, and 2 and 6-9 months after vasectomy, by indirect immunofluorescence techniques. Antisperm antibodies were detected in over 60% of the men between the ages of 22-51. Antibodies to 7 distinct sperm antigens were found, 5 of which were detectable by antibody in vitro, while the remaining 2 were detectable only after treatment of spermatozoa with dithiothreitol and trypsin. The incidence of antisperm antibodies rose from 61% before vasectomy, to 77% at 2 months and 90% at 6-9 months after vasectomy. 2 general classes of antibodies were established on the basis of their incidence prior to vasectomy. The 1st group (natural antibodies) included antibodies to antigens in the acrosome with a diffuse distribution, the equatorial region, the postacrosomal region, and the mid-section of the tail. The incidence of this class of antibody increased from 61% before vasectomy to 73% at 2 months and 80% at 6-9 months. The second class (immune antibodies) included antibodies to the sperm nucleus, the tail, and to discrete antigens over the acrosome. These increased from 3% before vasectomy to 25% at 2 months and 58% at 6-9 months. Both classes could be classified as both IgM and IgG, with the exeption of antibodies to sperm nucleus, which were almost exclusively IgG. Autoantibodies such as antinuclear, automitochondrial, and anti-smooth muscle antibodies did not develop after vasectomy.
...
PMID:Human sperm antigens and antisperm antibodies I. Studies on vasectomy patients. 110 22

The influence of enzyme or antiprogesterone antiserum treatment on the penetrability of rabbit ova was studied. Ova were recovered from oviducts, treated for varying periods of time with either trypsin, chymotrypsin, neuraminidase or antiprogesterone antiserum, and then transferred alone, or with control ova, to the oviducts of inseminated animals. 3 hours after transfer, they were recovered and examined for penetration of the vitellus and for the number of spermatozoa present in the perivitellum space or zona pellucida. Although no vitrelline penetration was observed in ova treated with the higher concentration of neuraminidase, the number of spermatozoa passing through the zona pellucida was not affected. Trypsin, chymotrypsin, and antiprogesterone antiserum treatment had only a slight effect on spermatozoic penetration of the zona pellucida and vitellus. There was no significant difference in ova penetrability between treated and control groups. It is concluded that trypsin and chymotrypsin do not affect any possible "fertilizin-like" substance of the ovum.
...
PMID:The penetrability of rabbit ova treated with enzymes or anti-progesterone antibody: a probe into the nature of a mammalian fertilizin. 117 79

Proteolytic activity in the acrosomes of ejaculated bull spermatozoa was demonstrated using an autoradiographic film as a gelatin substrate. Incubation of the spermgelatin adducts at +37 degrees C and 94% humidity, which was kept constant by ventilating an incubator with water-saturated compressed air, yielded reproducible results. Gelatin depolymerisation started adjacent to the posterior segment of the acrosome within 30 to 60 s after application of individual spermatozoa to the substrate membrane and, finally, increased to a white circular digestion area enveloping the entire sperm head. The observed gelatinolysis seems to be mainly caused by acrosin, the trypsin-like acrosomal proteinase. This conclusion is supported by the positive correlation (r = +0.83, P is less than or equal to 0.01) found between the mean values of the lysis areas of individual spermatozoa on gelatin films and the acrosin activity of the sperm population measured with Bz-Arg-OEt as substrate after acidic extraction of the spermatozoa. In addition, prior saturation of the substrate layers with acrosin inhibitor (SSPI-I, II) from boar seminal plasma prevented the lysis reaction. Extraction of acrosin from the spermatozoa before application to the gelatin membranes resulted in a complete loss of any proteolytic activity. If spermatozoa were stored for 4 to 6 days at +4 degrees C or -20 degrees C in Tris buffer and afterwards applied to the substrate layer, lysis areas of individual spermatozoa differed markedly. Spermatozoa from undiluted ejaculated frozen at -20 degrees C showed no proteolytic effect on gelatin films. In general, there was a high correlation (r = +0.83, P is less than or equal 0.01) between the number of "living cells" characterized by live-dead staining and the percentage of spermatozoa active on the substrate membranes.
...
PMID:The lysis effect of bull spermatozoa on gelatin substrate film methodical investigations. 118 Dec 57

1. A simple method is given for isolating from ram spermatozoa a water-soluble form of acrosin (a trypsin-like enzyme) which is about 25% pure. It is free from an acrosin inhibitor which is located in the spermatozoa. 2. In the hydrolysis of N-alpha-benzoyl-l-arginine ethyl ester the degree of activation of acrosin by Ca(2+), and by some other cations, is dependent on the extent of contamination by the inhibitor. In 50mm-Tris-HCl buffer (pH8.2) activation by Ca(2+) did not exceed 40%, but acrosin that is partially inhibited may be activated by up to 300%: this is due to cation-mediated protection of acrosin against the inhibitor. 3. Increasing concentrations of buffers (e.g. Tris) also activate acrosin but at above certain buffer concentrations Ca(2+) no longer exerts an activating effect and may become inhibitory. Ca(2+) is also inhibitory when added to assay systems involving anionic buffers with chelating properties. This is due to a fall in pH. 4. The above results suggest reasons for conflicting conclusions in papers dealing with the effects of Ca(2+) on acrosin activity. 5. Inhibition of acrosin by the Kunitz pancreatic trypsin inhibitor is increased on addition of Ca(2+). Inhibitions of trypsin by the acrosin inhibitor and by the Kunitz inhibitor are insensitive to Ca(2+). 6. Like trypsin, acrosin is activated, up to 60%, by 2-methyl-propan-2-ol, dimethyl sulphoxide, and some other water-miscible solvents. Effects of cations and solvents tend to be additive and a common maximum acrosin activity can be achieved with various concentrations of solvent, salts and buffer in the assay system. Activation by solvents is increased when low concentrations of the acrosin inhibitor are present. 7. Activations of acrosin by salts and by solvents are more pronounced when the substrate is N-alpha-benzoyl-dl-arginine 2-naphthylamide. 8. K(m) values for ram acrosin (about 0.2mm) are much higher than those for trypsin, and k(cat.) values are slightly higher than those for trypsin. Considerations of the influences of ions and dimethyl sulphoxide on the activities and kinetic constants of acrosin and trypsin suggest that conformational changes are the factors mainly responsible for the reported activations of acrosin. 9. The following conclusions are reached. (a) Acrosin plays a role in the penetration of the sperm cell into the egg without becoming detached from the acrosomal membrane. (b) The enzyme is a peripheral membrane protein which may be classed as a cathepsin. (c) The susceptibility of the activity of soluble acrosin to cations and solvents points to a flexible molecule, i.e. one lacking conformational restraints imposed by association (presumably ionic) with the acrosomal membrane.
...
PMID:Studies on ram acrosin. Isolation from spermatozoa, activation by cations and organic solvents, and influence of cations on its reaction with inhibitors. 119 Dec 54

When denuded ram spermatozoa were suspended in weakly buffered 0.25M sucrose, the acrosin remained bound to the acrosomal membranes of the sperm heads. Media containing CaCl2 caused complete solubilization of the enzyme. Effects of acrosin inhibitors on soluble and bound enzyme were studied in Tris HCl(pH 8.2) containing sucrose. Denuded spermatozoa were used as a preparation of bound acrosin. Trasylol (Kunitz basic pancreatic trypsin inhibitor) acted more strongly on bound scrosin than on soluble acrosin, but soya-bean trypsin inhibitor acted more strongly on soluble acrosin. At concentrations 0.5 - 2.0muM, the inhibitors isolated from ram acrosomes and from ram seminal plasma inhibited soluble acrosin but had negligible effects on bound acrosin. However, bound acrosin was sensitive to high concentrations of the acrosomal inhibitor. The two forms of acrosin were inhibited to about the same degree by p-aminobenzamidine and also by Tos-Lys-CH2Cl. It is proposed that membrane-bound acrosin is the form that functions in penetration of the zona pellucida, and that a role for acrosin inhibitors is suppression of an antifertility effect of soluble acrosin on mammalian eggs. This hypothesis is supported by 1) the results of work on the impaired fertilizing capacity of rabbit spermatozoa that have been treated with acrosin inhibitors, 2) the anti-fertility effects on hamster eggs of solutions of acrosin and of bovine trypsin, and 3) the results in this paper.
...
PMID:Effects of acrosin inhibitors on the soluble and membrane-bound forms of ram acrosin, and a reappraisal of the role of the enzyme in fertilization. 124 98

Cock spermatozoa, like trypsin, induced a rapid fall in the viscosity of gelatin solutions but ram spermatozoa and inhibitor-free ram acrosin were ineffective. The gelatin-hydrolysing activity in cock spermatozoa was solubilized at pH 8 in the presence of calcium ions but comparable extracts of ram spermatozoa were inactive. Both extracts showed acrosin activity (assayed with benzoylarginine ethyl ester). The two catalytic activities of cock spermatozoa were each susceptible to the same trypsin inhibitors and during fractionations they were not separable. We deduce that cock acrosin, and probably some other avian acrosins, have the power to degrade dissolved gelatin while ram acrosin does not. The acrosin in cock spermatozoa, unlike that in ram spermatozoa, was inactivated at pH 2-7. Acid extracts of the former contain an inactive precursor of acrosin which undergoes spontaneous re-activation in buffers, pH 8, containing calcium ions. In this respect it resembles the proacrosin of rabbit testis.
...
PMID:Comparison of neutral proteinase activities in cock and ram spermatozoa and observations on a proacrosin in cock spermatozoa. 127 37

Acrosome of human sperm possesses two distinct antigens that are immunogenic, and will elicit autoantibodies that are detectable by immunofluorescence (IF). The first antigen, Acl, diffuse in distribution, is probably glycoprotein in nature since it is removed by trypsin and periodate. It is readily removed from cells after incubation in acid buffer or phosphate-buffered saline (PBS), stable at 60 degrees C and not affected by trypsin inhibitor. The second antigen, Ac2, discrete in distribution, is resistant to trypsin treatment. It remains stable after incubation in acid buffer or PBS, is unstable at 60 degrees C and becomes more diffuse in distribution when incubated in acid buffer or trypsin inhibitor. The use of spermatozoa pretreated with acid buffer permits detection of anti-Ac2 antibody that coexists with anti-Ac1 antibody in the same serum sample. Both Ac1 and Ac2 antigens are demonstrable in spermatozoa from the ejaculate, epididymis and the testis; in spermatids and spermatocytes. Ac1 antigen appears to show extensive cross-reaction with micro-organisms and with antigen(s) of human adrenal gland; and anti-Ac1 antibody is found frequently in the serum of men before vasectomy. In contrast, Ac2 antigen does not show cross-reaction with micro-organisms or tissue antigens tested; and its antibody is found mainly in the male and primarily after vasectomy. Thus, anti-Ac2 antibody may be more indicative of an immune response to sperm, and should be sought in diseases related to sperm immunity.
...
PMID:Human sperm antigens and antisperm antibodies. III. Studies on acrosomal antigens. 127 79

Mammalian sperm acrosomes contain a trypsin-like protease called acrosin which causes limited and specific hydrolysis of the extracellular matrix of the mammalian egg, the zona pellucida. Acrosin was localized on hamster, guinea-pig and human sperm using monoclonal and polyclonal antibodies to human acrosin labelled with colloidal gold. This was visualized directly with transmission electron microscopy, and with light and scanning microscopy after silver enhancement of the colloidal gold probe. Four distinct labelling patterns were found during capacitation and the acrosome reaction in hamster and guinea-pig spermatozoa, and three patterns were found in human spermatozoa. In the hamster, acrosin was not detected on the inner acrosomal surface after the completion of the acrosome reaction, thus correlating with the observation that hamster spermatozoa lose the ability to penetrate the zona after the acrosome reaction. With guinea-pig and human spermatozoa, acrosin was still detected after the completion of the acrosome reaction, thus correlating with the observation that acrosome reacted guinea-pig spermatozoa bind to and penetrate the zona pellucida.
...
PMID:Immunodetection of acrosin during the acrosome reaction of hamster, guinea-pig and human spermatozoa. 134 78

Caltrins, small basic proteins that inhibit calcium uptake by epididymal spermatozoa, have been purified from seminal vesicle content of the mouse and rat. Mouse caltrin (M(r) 8,476) contains 75 amino acid residues, 14 basic, 5 acidic, and 7 cysteines while rat caltrin (M(r) 6,217) has 56 residues, 10 basic, 5 acidic, and 6 cysteines; their pI values are 10.2 and 9.3, respectively. The proteins did not react with Ellman's reagent unless the cystine residues were previously reduced. The primary structures were determined by sequencing fragments generated by trypsin, clostripain, and endoproteinase Lys-C digestion. The sequences were ordered to give the total structural formula. The two molecules have no sequence similarity and are different from those of the bull and guinea pig previously reported. Only rat caltrin has a sequence of 13 residues nearly identical to that in guinea pig caltrin I. Both rat and mouse caltrin react with antibodies against bovine and guinea pig caltrins. Reduction and alkylation of cysteine residues suppressed the immunologic response of mouse caltrin; however, modified rat caltrin retained partially its immunoreactivity with the antiserum against guinea pig caltrin I. The same treatment abolished the calcium transport inhibitory activity of mouse caltrin and greatly reduced that of rat caltrin. It is likely that rat and mouse caltrins have the same physiological function as proposed for bovine caltrin; namely, to regulate the development of the Ca(2+)-dependent processes that "capacitate" sperm for fertilization.
...
PMID:Purification, structure, and characterization of caltrin proteins from seminal vesicle of the rat and mouse. 140 Apr 6


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---