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)

The trypsin-like enzyme acrosin has a key function in the fertilization process enabling penetration of the zona pellucida of the ovum by the spermatozoa. Under experimental conditions acrosin inhibitors are able to prevent fertilization. In the male genital tract high amounts of low molecular weight acid-stable proteinase inhibitors are found having mainly protective functions, but may play also a significant role in the process of capacitation. Aside from biochemical and physiological investigations the presented studies are a contribution towards the clinical applicability of the acrosin-inhibitor system with special respect to its diagnostic and prognostic value for andrology. In addition, inhibition of acrosin may be an approach for an effective contraceptive method.
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PMID:[The significance of acrosin and proteinase-inhibitors in human reproduction]. 30 Jul 3

Exposure of rabbit ova to wheat germ agglutinin (WGA) at a concentration of 50 microgram/ml for 30-45 min rendered the zona pellucida at least 10 times more resistant to digestion by 1 mg trypsin/ml, and also more resistant to acrosin. Nevertheless, the zonas of WGA-treated eggs were penetrated by spermatozoa as readily as those of untreated eggs in the same oviduct. These results suggest that penetration of spermatozoa through the zona pellucida may not require the agency of a trypsin-like enzyme acting as a primary zona lysin. The validity of the general belief that a lysin in necessary for zona penetration is considered briefly in relation to the mode of penetration and structural organization of the mammalian sperm head.
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PMID:Normal penetration of rabbit spermatozoa through a trypsin- and acrosin-resistant zona pellucida. 36 50

The survival curves for a population of reactivated spermatozoa exposed to digestion by trypsin indicate that a large number of trypsin-sensitive targets must be digested before the flagellum disintegrates. Changes in flagellar movement during trypsin digestion can be very small, especially when the spermatozoa are reactivated at 0.25 M KCl. They are not the changes which would be expected if elastic resistance of the trypsin-sensitive structures responsible for maintaining the integrity of the axoneme is a significant determinant of flagellar bend amplitude. By carrying out trypsin digestion under a variety of conditions, at least six distinct effects of trypsin digestion on parameters of flagellar movement have been detected. These include a gradual increase in the rate of sliding between tubules, gradual and abrupt changes in beat frequency accompanied by reciprocal decreases in bend angle, changes in the symmetry and planarity of bending, and selective interference with mechanisms for bend initiation and bend propagation.
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PMID:Motility of triton-demembranated sea urchin sperm flagella during digestion by trypsin. 56 84

Gelatinolytic activity of whole mouse spermatozoa was demonstrated by the gelatin film test. The presence of a trypsin-like protease (acrosin) in acidic extracts of mouse spermatozoa was shown by an electrophoretic method to separate the enzyme from a putative inhibitor.
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PMID:Demonstration of acrosin in mouse spermatozoa. 64 3

Acidic extracts of washed, ejaculated human spermatozoa contain, besides acrosin, two proteinase inhibitors, a trypsin-chymotrypsin (elastase) inhibitor (HUSI-I) and a trypsin-acrosin inhibitor (HUSI-II). Using the indirect immunofluorescence technique these inhibitors could be localized in the spermatozoa. Ejaculated spermatozoa were treated with monospecific antibodies raised in rabbits against HUSI-I and HUSI-II, respectively, and with fluorescein-labeled IgG from goat directed against the rabbit IgG. If acetone-fixed spermatozoa were used, fluorescence appeared only in a small ring near or at the equatorial segment of the spermatozoa. After prefixation of washed spermatozoa with 0.36% formaldehyde, however, distribution of both inhibitors in the region of the acrosomal caps could clearly be demonstrated. Present results suggest that they are attached at the plasma membrane. Obviously, in the case of human spermatozoa the inhibitors are relatively easily detached together with the membrane so that prefixation is necessary to achieve proper localization.
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PMID:Localization of seminal plasma proteinase inhibitors in human spermatozoa as revealed by the indirect immunofluorescence technique. 79 87

Two forms of proacrosin have been purified from ejacualted boar spermatozoa. The isolation method utilized benzamidine to inhibit the premeture activation of the zymogen and included pH precipitation, ammonium sulfate fractionation, and sodium chloride precipitation. Further purification was achieved by Sephadex G-200 FILTRATION OF THE PREPARATION AFTER IT WAS TREATED WITH 8 M urea. The overall proacrosin yield was 58% with a specific acitivity of 253 units/mg of protein. The molecular weights of the proacrosins determined by sodium dodecyl sulfate disc gel electrophoresis were 55,000 and 53,000. Proacrosin autoactivation followed the classical S-shaped activation curve and calcium was not required to obtain full activation. Time course activation studies in 0.1 M Tris/HCl, pH 8.4, at 0 degrees were monitored with sodium dodecyl sulfate-disc gel eletrophoresis and anlytical gel electrophoresis with staining techniques for protein and enzymatic activity. Under the conditions used, the zymogens were sequentially degraded to three different active specise of acrosin (alpha, beta, and gamma). The approximate molecualr weights of the acrosins were 49,000, 39,000, and 25,000 for the alpha, beta, and gamma forms, respectively. The autoactivation is concentration-dependent and can be proteolytically stimulated with either alpha- or beta-acrosin and trypsin, indicating the activation of proacrosin can via a bimolecular process.
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PMID:Boar proacrosin. Purification and preliminary activation studies of proacrosin isolated from ejaculated boar sperm. 84 51

Nuclear basic protein from ejaculated human spermatozoa were labelled with iodo[14C1]acetic acid and fractionated by ion-exchange chromatography into several pools (named A-K). Gel electrophoresis indicated that the minor protamine components, were present in pool D and that, of the major protamine components, component 1 (pools E, F, G, H) was well separated from the unresolved mixture of component 2 and component 3 (pools I, J, K). Pools G and J were free of other contaminants. Pools D, G, and J produced different radioactive peptides on digestion with trypsin and with thermolysin, and also had quite distinct amino acid compositions. This suggests that the heterogeneity of human protamines is caused by differences in amino acid sequence. Major component 1 also seems to be heterogenous, since it was found in two distinct peaks (pools E and G), but post-translational modification as a cause of the two types of component 1 has not been ruled out. Although all the human protamine components are similar to other mammalian protamines in containing half-cysteine and tyrosine, they also have unique common features such as high histidine and high glutamic acid contents.
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PMID:The heterogeneity of the protamines from human spermatozoa. 95 98

Human acrosin was purified to electrophoretically homogeneous forms by acidic extraction of washed ejaculated spermatozoa and gel filtration of the acidic extracts on Sephadex G-75, followed by affinity chromatography on p-amino-benzamidine Sepharose. Human acrosin exists in at least four molecular forms. The apparent molecular weights of three forms were determined to be 64 000, 38 000 and 25 000, respectively. The high molecular weight form is transformed to the low molecular weight forms by incubation of the acrosin preparation obtained from freshly ejaculated spermatozoa in solutions of pH near 7. Like boar acrosin, human acrosin is also a glycoprotein and therefore reversibly bound to Concanavalin A-Sepharose. The amino acid composition of the 25 000 molecular weight form is similar to that of human trypsin. Rabbit anti-boar-acrosin gamma-globulins form a precipitate with human acrosin, but not with porcine trypsin or human plasmin. The relationship between the occurrence of multiple acrosin forms and proenzyme activation by limited proteolysis is discussed.
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PMID:Multiple forms of human acrosin: isolation and properties. 98 58

Galline, a protamine of domestic fowl, was obtained by two preparation procedures from the semen of a strain of White Plymouth Rock and submitted to fractionation by column chromatography on Bio-Gel CM-30. In the first procedure the specimen prepared from sperm heads was purified by the use of distilled water and dilute acetic acid and fractionated into almost eight fractions (G-I-G-VIII) in the same way as the specimen from a strain of New Hampshire (1,2). No difference could be found between galline specimens from the two different strains based on the amino acid and terminal analyses of each fraction. The specimen of galline from sperm heads purified with 1% citric acid (the second procedure) was composed of only one component, which was isolated as a single peak. The smaller fractions, G-I-G-VII, were found to be derived from G-VIII by the action of trypsin-like protease contained in the extract of sperm heads with 1% citric acid. This enzyme seems to originate in the acrosome of fowl spermatozoa. Consequently, it is concluded that intact galline is composed of only one molecular species and its total amino acid sequence is represented by the completed formula of G-VIII as shown in the preceding paper (4).
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PMID:Studies on a protamine (galline) from fowl sperm. 4. Degradation of galline by trypsin-like protease of fowl sperm heads. 99 42

Lysozyme, alpha-amylase, neutral proteinase and plasminogen activator were most concentrated in the initial portion of the ejaculate that consists mostly of Cowper's gland and prostate gland fluids as well as spermatozoa. The concentration of the high molecular weight proteinase inhibitors, alpha1-antitrypsin and alpha1X-antichymotrypsin, was essentially unaltered throughout the ejaculate fractions, although their absolute amounts showed an increase towards the final fraction. By contrast, the total inhibitory activity towards pancreatic trypsin was highest both in concentration and amount in the last fraction, thus indicating that the seminal vesicles are its primary source. Plasminogen, prothrombin, Factor XIII, and the proteinase inhibitors antithrombin III, alpha2-macroglobulin, inter-alpha-trypsin inhibitor and C1S-inactivator could not be detected immunochemically in whole ejaculates, and indicates the dissimilarity between the coagulation/liquefaction processes of semen and blood.
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PMID:Components of human split ejaculates. II. Enzymes and proteinase inhibitors. 108 6


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