Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 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.
 ...
PMID:Hydrolysis of the hen egg vitelline membrane by cock sperm acrosin and other enzymes. 0 Apr 54

Further evidence is presented that the acrosomal proteinase acrosin exists as a zymogen precursor in freshly ejaculated boar spermatozoa. Autoactivation of proacrosin to acrosin takes place optimally at slightly alkaline pH and in the presence of calcium ions. Activation is considerably accelerated by catalytic amounts of trypsin or highly purified acrosin. A significant acceleration of the activation is also achieved by porcine pancreatic and urinary kallikrein, whereas chymotrypsin, plasmin, thrombin or urokinase showed no effect. Activation can be inhibited by p-amino-benzamidine and p-nitrophenyl p'-guanidino-benzoate. Electrophoretic analysis at different stages of activation revealed that during this process various molecular forms of acrosin are produced, apparently by limited proteolysis.
 ...
PMID:Multiple forms of boar acrosin and their relationship to proenzyme activation. 0 66

The pH of the hamster sperm acrosome was estimated by a method based on the distribution of monoamines between membrane enclosed volumes maintaining pH gradients. A fluorescent amine, 9-aminoacridine, was used to permit both microscopic and fluorometric measurements of amine distribution. Cauda epididymal hamster sperm incubated with 9-aminoacridine accumulated the amine in the acrosomal volume. In the presence of NH4Cl or the ionophore Nigericin (compounds which discharge pH gradients) 9-aminoacridine fluorescence disappeared from the acrosome. Amine distribution between the acrosome and external volume was estimated by fluorometric measurement of sperm filtrates in the presence and absence of NH4Cl and Nigericin. These values, together with an estimated acrosomal volume of 0.4mu3 were used to calculate an acrosomal pH of less than 5. In addition, an acrosomal pH of 5 or less was obtained with 14C-methylamine. We suggest that such an acidic acrosomal pH of 5 or less could serve to inhibit the activation or autoactivation of the acrosomal zymogen proacrosin to acrosin, a trypsin-like enzyme involved in fertilization.
 ...
PMID:The pH of the hamster sperm acrosome. 2 69

By means of selective solubilization methods and slab gel electrophoresis, reproducible patterns of 19, 37, and 56 protein bands were found to be associated with nuclear, "flagellar," and total human spermatozoa, respectively. Forty protein bands were found between the molecular weight of 12,400 to 160,000 daltons. Twelve bands were associated with values lower than 12,400 daltons. The nuclear major bands were located in a low molecular weight zone, while "flagellar" ones were located in a high molecular weight zone. None of these bands represents degradation products since a) in the solubilized samples neither acrosin, chymotrypsin, nor trypsin activities were present, b) in the presence of two protease inhibitors the same electrophoretic patterns were observed, and c) labelled globins added during sample manipulation were quantitatively recovered without degradation.
 ...
PMID:Electrophoretic patterns of total, nuclear, and flagellar proteins from ejaculated human spermatozoa. 3 Jul 19

Activation of chymotrypsinogen by bovine trypsin or boar sperm acrosin was followed up using Nalpha-acetyl-L-tyrosine ethyl ester in a highly sensitive test system. Inhibition studies employing antiboar acrosin rabbit gamma-globulins showed the following results. 1) Whereas the acrosin-induced activation velocity was significantly depressed in the presence of the antibodies, the trypsin-catalyzed activation rate was not diminished. 2) The antibodies enhanced the acrosin-catalyzed cleavage rate of BzArgOEt significantly, but not the trypsin-catalyzed cleavage rate of this substrate. 3) Autodigestion of acrosin was considerably reduced in the presence of the antibodies. The enzymatic test system used is especially suitable to study the specificity of acrosin antibodies or their affinity to related enzymes if only small amounts of these substances are available.
 ...
PMID:Activation of chymotrypsinogen by boar acrosin and its prevention by antiboar acrosin rabbit gamma-globulins. 6 99

Common antigenic determinants between two species of pancreatic trypsin and twelve species of acrosin were studied using a highly sensitive, enzyme-linked immunoassay. No common antigenic determinants between trypsin and acrosin could be detected.
 ...
PMID:Evidence for the dissimilarity of acrosin and pancreatic trypsin as revealed by a sensitive immunoassay. 6 80

Two acid stable proteinase inhibitors are present in bull seminal plasma and washed ejaculated bull spermatozoa. Inhibitor I with a molecular weight of about 8700 (estimated by gel filtration) is a very strong inhibitor of bull sperm acrosin but also inhibits bovine trypsin and chymotrypsin and porcine plasmin; inhibition of porcine pancreatic and urinary kallikrein was not observed. In this respect inhibitor I resembles the well known cow colostrum trypsin inhibitor. Inhibitor II with a molecular weight near 6800 (estimated by gel filtration) inhibits bovine trypsin and chymotrypsin, porcine plasmin and pancreatic and urinary kallikrein as well as bull acrosin. The inhibition specificity of inhibitor II is thus very similar to that of the basic inhibitor from bovine organs (Kunitz-type). In view of the inhibition strength and other characteristics, however, the acid stable bull seminal inhibitors are not identical with the inhibitor from cow colostrum or bovine lung (organs).
 ...
PMID:Characterization of the proteinase inhibitors from bull seminal plasma and spermatozoa. 13 81

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.
 ...
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.
 ...
PMID:Normal penetration of rabbit spermatozoa through a trypsin- and acrosin-resistant zona pellucida. 36 50

An acrosin inhibitor was isolated from bull seminal plasma by gel filtration on Sephadex G-50 fine and ion-exchange chromatography on CM-Sephadex. The inhibitor is a basic polypeptide (pl greater than or equal to 10.5) of molecular weight 6 200 (calculated from amino acid composition). Its N-terminal amino group is blocked. The inhibitor is not strictly specific in its effect since it also inhibits trypsin and to a lesser degree chymotrypsin, in addition to bull and boar acrosin.
 ...
PMID:Isolation of basic acrosin inhibitor from bull seminal plasma (BUSI II). 39 4


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