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

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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)

A method for the isolation and culture of epididymal epithelial cells obtained from pubertal and old adult rats is described. This method permits the establishment of primary cultures of these cells in monolayers from aggregates isolated from whole epididymides and major epididymal anatomical segments (caput, corpus, and cauda) after trypsin and collagenase digestions. A large number of cultured epididymal cells retain a differentiated function as demonstrated by the immunocytochemical and radioimmunoassay finding of acidic epididymal glycoprotein, a spermatozoa-coating protein secreted by the principal cells of rat epididymis. The proliferative potential of cultured epididymal cells obtained from pubertal and old adult donors can be documented by [3H]thymidine labeling and mitotic indices without significant loss of gene expression for acidic epididymal glycoprotein. Results of this study demonstrate that epididymal epithelial cells, consisting of a predominant population of principal cells, can be isolated, cultured, and maintained for up to 3 months.
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PMID:Isolation, culture, and immunocytochemical characterization of epididymal epithelial cells from pubertal and adult rats. 701 41

Rat epididymal spermatozoa were capable of rapid binding to various positively charged beads, but not to beads with negative or no charge. The binding appeared to involve the end-piece and perhaps a portion of the tail. The binding was quite resistant to acid, heat, Triton X-100, sodium dodecyl sulphate and trypsin. The bound spermatozoa could be slowly released from the beads in a concentrated solution of salts, the best among these tested was 1 M-ammonium acetate. The bead-binding property of the spermatozoa was employed to develop, a new, simple and inexpensive method to isolate heads and tails without the use of an ultracentrifuge. The yield of the heads from spermatozoa of the cauda epididymis was 65 to 80% with 2 to 10% of tails contaminating while the yield of the tail was 30 to 40% with no cross contamination.
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PMID:Binding of spermatozoa to positively charged beads as an inexpensive method to isolate sperm heads and tails. 720 82

Protease and basic amidase activity was found in the seminal plasma of the domestic turkey. Amidase activity, measured through use of N-alpha-benzoyl-DL-arginine-p-nitroanilide-HCL (BAPNA), was 23-28 times greater for turkey than for guinea fowl or chicken. Within the reproductive tract, seminal plasma from the vas deferens had much greater activity than testicular or epididymal fluids. Turkey seminal plasma enzyme (TSPE) purified by chromatography or isoelectric focusing showed three protein bands by PAGE, each resolving on SDS-PAGE into two subunits with molecular weights of approximately 28,000-32,000 and 38,000-44,000. One of the three proteins also contained a larger subunit (M(r) 76,000-81,000) thought to be transferrin. Turkey acrosin consisted of three subunits with molecular weights below 20,500. Acrosin, but not TSPE, was visualized in native gels with N-alpha-benzoyl-DL-arginine-beta-naphthylamide (BANA)/Fast Garnet stain. Michaelis constants (BAPNA) for TSPE, acrosin, and trypsin were 2.41 +/- 0.12 x 10(-4) M (n = 5), 4.96-6.03 x 10(-4) M (n = 2), and 6.76 +/- 0.95 x 10(-4) M (n = 6), respectively. TSPE, like acrosin and trypsin, was inhibited by benzamidine but not iodoacetamide. While all natural trypsin inhibitors tested inhibited acrosin, TSPE was not inhibited by ovomucoid from chicken or turkey egg white.
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PMID:Proteolytic enzymes in seminal plasma of domestic turkey (Meleagris gallopavo). 767 33

A trypsin-like protease was extracted with 1% cetyltrimethylammonium bromide (CTAB) at pH 7.0 from boar cauda epididymal sperm nuclei whose acrosin had previously been removed by acid extraction. The CTAB-extracted sperm protease (CSP) was purified by ion-exchange chromatography on CM-23, gel filtration on Sephadex G-100, affinity chromatography on benzamidine-CH-Sepharose 4B, and HPLC on CM-5PW. CSP is a two chain protein composed of M(r) 2.6K and M(r) 37K chains, which are covalently cross-linked by disulfide bonds. CSP exhibited a pH optimum between pH 8.0 and 9.0, and was inhibited by diisopropyl phosphorofluoridate, antipain, leupeptin, and 1-chloro-3-tosylamide-7-amino-L-2-heptanone. The activity of CSP was enhanced about 1.2-fold with 50 mM CaCl2, with which acrosin is enhanced 2.0-fold. The catalytic efficiency (kcat/Km) of CSP toward Bz-L-Arg-OEt, Tos-L-Arg-OMe, and Tos-L-Lys-OMe in the presence of 50 mM CaCl2 differed from that of acrosin by factors of 0.53, 1.2, and 0.80, respectively. Amino acid sequencing of V8-digested peptides of CSP, and its L- and H-chains showed that the amino acid sequence of CSP was closely related to, but different from, that of acrosin. These results suggest that CSP is a novel acrosin-like enzyme that differs from acrosin in its location in the sperm head, the effect of calcium ions on its activity, and its substrate specificity.
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PMID:Purification and characterization of a novel acrosin-like enzyme from boar cauda epididymal sperm. 782 68

Previous studies from this laboratory have identified a novel alpha-D-mannosidase on the sperm plasma membranes of several species, including man, which may have a role in fertilization. The polyclonal antibody raised against an isoform of the enzyme purified from rat epididymal fluid was found to cross-react with the alpha-D-mannosidase activity present in the detergent-solubilized spermatozoa and sperm plasma membranes. In the present study, we have used affinity-purified as well as monospecific anti-mannosidase IgG to demonstrate that the sperm mannosidase is an integral plasma membrane component of the rat sperm and is localized on the periacrosomal region of the sperm head. In addition, we demonstrate proteolytic processing of the membrane-bound alpha-D-mannosidase during maturation of spermatozoa. The membrane fractions prepared from testis, and spermatozoa from the caput, corpus, and cauda regions of the epididymis, were solubilized in SDS and resolved by SDS-PAGE. The resolved polypeptides, when subjected to Western blot analysis using affinity-purified anti-mannosidase IgG as the primary antibody, revealed the presence of three specific immunoreactive bands (apparent M(r), 135, 125, and 115 kDa) in the membranes from testis, caput, and corpus spermatozoa. However, the cauda sperm plasma membranes showed only one immunoreactive band of apparent M(r) 115 kDa. The disappearance of the 135-and 125-kDa forms and the appearance of a sharp 115-kDa band on cauda spermatozoa suggests a precursor-product relationship between various molecular forms of the enzyme. Trypsin treatment of testicular and caput sperm membranes largely converted the precursor forms to the mature (115-kDa) form. The in vitro proteolysis resulted in an elevated level of the alpha-D-mannosidase activity in the caput (but not cauda) sperm plasma membrane. Inclusion of trypsin inhibitors (benzamidine and aprotinin) largely prevented the conversion of precursor form to the mature form. These data are consistent with the observed increase in the levels of sperm enzyme activity as spermatozoa move from the caput to the cauda region and suggest that the increase is due to the conversion of enzymatically inactive/less active high molecular weight precursor forms (135 and 125 kDa) into enzymatically active mature form (115 kDa) during sperm maturation.
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PMID:Rat sperm plasma membrane mannosidase: localization and evidence for proteolytic processing during epididymal maturation. 787 80

The binding of N-acetyl-beta-D-glucosaminidase from rat epididymal fluid to the surface of spermatozoa from the cauda epididymis was measured in the presence of sugars, its phosphorylated derivatives, or after treatment of the cells or the enzyme with agents that alter the integrity of proteins or carbohydrates. The binding was saturable, with a Kd in the nanomolar range, was inhibited with phosphorylated derivates of fructose, and did not depend on Ca2+, showing that it is different from the mannose 6-P-recognizing system existing in other tissues for this and other acid hydrolases. Treatment of the cells with sodium periodate or trypsin inhibited the binding, showing that a glycoprotein of the plasmalemma is involved in the affinity site. Fructose or phosphorylated derivates were not detected in the proteins of the epididymal fluid with HPLC. However, with the method used, the presence of these compounds cannot be ruled out, if among the proteins of the fluid there are only a small number of acid hydrolases containing this sugar.
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PMID:Affinity sites for N-acetyl-beta-D-glucosaminidase on the surface of rat epididymal spermatozoa. 800 7

A basic 54-kDa protein (pI approximately 8.8) that cross-reacts with anti-caltrin antisera has been detected and isolated by gel filtration and cation exchange chromatography from seminal vesicle content of the rat. The soluble protein spontaneously precipitated in NaHCO3-buffered solution at pH 7.8, but it was kept soluble in imidazole buffer containing EDTA and dithiothreitol at pH 7.0. In addition to the main band of 54 kDa, two faint immunoreactive fractions with molecular weights around 45,000 and 14,000 were also revealed by Western blotting. The presence of the rat caltrin sequence within the primary structure of the 54-kDa molecule has been investigated by sequencing the peptides generated by trypsin digestion. The sequence of the first 46 amino acid residues of rat caltrin has been found in one of the fragments produced by enzymatic cleavage. However, the exact location of the caltrin sequence in the whole 54-kDa protein has not been determined. The purified 54-kDa protein did not inhibit Ca2+ uptake by epididymal spermatozoa. Results indicated that this molecule represents an inactive precursor of caltrin and is enzymatically processed in the lumen of the seminal vesicle to the small and active calcium transport inhibitor protein. The immunoreactive proteins with intermediate molecular weights (45,000 and 14,000) could represent partially degraded products of the precursor. The lack of inhibitory activity of the precursor may be related to the molecule's having a size and conformation that would make it unable to interact with caltrin receptors on the sperm surface.
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PMID:Isolation and characterization of a 54-kilodalton precursor of caltrin, the calcium transport inhibitor protein from seminal vesicles of the rat. 831 86

In the preceding study (Okamura et al., 1992; Biol Reprod 47:1040-1052) we suggested that a 135-kDa protein secreted by porcine epididymis is involved in the sperm maturation. In this work, we have isolated the cDNA clone coding the 135-kDa protein in an effort to investigate its structure and function. The 135-kDa protein was purified from porcine cauda epididymal fluid. Three oligonucleotide probes were synthesized according to the amino acid sequences of N-termini of the native protein and trypsin-digested peptides. A cDNA clone hybridizing with these three probes was isolated from the cDNA library derived from the porcine proximal corpus epididymis. It encodes a novel protein with 1,006 amino acid residues in an open reading frame. Its overall amino acid sequence was significantly homologous (25.7%) to the alpha-mannosidase precursor of Dictiostelium discoideum (P34098). The 135-kDa protein could digest both p-nitro-phenyl-alpha-D-mannoside and high mannose oligo saccharide (Man8-GlcNAc2), strongly suggesting that it is an alpha-mannosidase homologue. The expression of this protein was specific to porcine and was localized to the very narrow parts of epididymis: the border of the caput and corpus epididymis. This protein may serve as a good marker for the functional differentiation in porcine epididymis. A possible role of this protein in the species-specific sperm-egg interaction is discussed.
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PMID:Cloning of complementary DNA encoding a 135-kilodalton protein secreted from porcine corpus epididymis and its identification as an epididymis-specific alpha-mannosidase. 856 59

125I-labeled protein D was shown to bind to whole rat epididymal sperm in a time-dependent, saturable, and reversible manner. Scatchard analysis indicates that there are 3.4 x 10(5) binding sites/sperm cell with a binding efficiency (Kd) of 2.3 x 10(-10) M. Binding of protein D to sperm reaches equilibrium by 95 min. and is reversible by 30 min. Specific binding of protein D to sperm pre-treated with a dilute trypsin solution is reduced significantly when compared with controls. Our findings establish that protein D-specific binding proteins displaying characteristics of a true receptor are present on the surface of rat epididymal sperm.
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PMID:Characterization of high-affinity protein D binding sites on the surface of rat epididymal spermatozoa. 895 90

Guanidinobenzoatase (GB), a proteolytic enzyme found in the epididymal fluids of mice, was purified to apparent homogeneity by molecular sieving and affinity chromatography. It has a molecular mass of 71 kDa and its enzymatic activity is heat labile and sensitive to EGTA. Its kinetic parameters (K(m) of 6.66 microM and a Vmax of 4.38 nmol/min/mg) were determined using 4-methylumbelliferyl-p-guanidinobenzoate (MUGB) as the substrate. GB activity is concentrated in the cauda epididymal region of the genital tract. Heat-solubilized whole zonae, biologically active ZP3, and several serine proteinase inhibitors, including a proteinase inhibitor endogenous to the male genital tract, effectively block the ability of GB to hydrolyze MUGB. Pretreating cumulus-free, zonae intact oocytes with purified GB reduces, in a concentration-dependent manner, the number of sperm able to bind to the zonae. The function of the soluble enzyme is not known. Its ability to bind both trypsin inhibitors and ZP3 suggests a possible role in gamete recognition.
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PMID:Characterization of the guanidinobenzoatase in the epididymal fluids of the mouse. 913 23


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