Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An analogue of porcine insulin which differs from the native molecule in that the amino-acid residue B22-L-arginine is replaced by its D-enantiomer has been synthesized. The [D ArgB22]B-chain was synthesized by the segment condensation method and purified as the di-S-sulfonate by ion exchange chromatoggraphy on SP-Sephadex at pH 3.5. Combination with native porcine sulfhydryl A-chain gave [DArgB22]insulin which was purified by ion exchange chromatography on SP-Sephadex at pH 4.5 with a linear NaCl gradient. The biological activity of this analogue as measured by glucose oxidation in rat epididymal adipocytes was 2%. Thymidine incorporation into DNA of human fibroblast was 16%. The immunoreactivity using antipork insulin antibody in a double antibody immunoassay was 4%. The receptor-binding affinity as measured by radioreceptor assays was 2% with cultured human fibroblasts and 1% with rat adipocytes. These results suggest that the L-configuration at B22-arginine is essential for retaining the biological, immunological and receptor-binding properties of the hormone.
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PMID:[B22-D-arginine]insulin: synthesis and biological properties. 676 Dec 62

The substrate specificity of rat testicular and epididymal peptidase was investigated using chromogenic substrates, D. L-alanine-, L-arginine-, gamma-N-L-glutamine-, L-leucine-, D. L-methionine-, alpha-N-benzoyl-D. L-arginine-, and N-benzoyl-L-leucine-beta-naphthylamide. The histochemical distribution of peptidase activity demonstrated with these substrates was also investigated in the testis and epididymis. L-Arginine-beta-raphthylamide (Arg-beta-NA) and gamma-N-L-glutamine-beta-naphthylamide (Glu-beta-NA) were mostly hydrolyzed in the testis and epididymis, respectively. Histologically, the activity using Arg-beta-NA as substrate (aminopeptidase B) appeared in both the cytoplasms and nuclei of interstitial cells and spermatogonia and the heads of spermatozoa, while activity using other substrates was found only in the cytoplasms of cells in the germinal epithelium. In the epididymis, strong reaction with Glu-beta-NA (gamma-glutamyl transpeptidase) was found in the apical part of the epithelial cells and in the heads of spermatozoa. Neither alpha-N-benzoyl-L-arginine- nor N-benzoyl-L-leucine-beta-naphthylamide was utilized in either the testis or the epididymis.
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PMID:Substrate specificity and histochemical distribution of aminopeptidase in rat testis and epididymis. 705 30

A new melanocyte-stimulating peptide has been isolated from acid extracts of frozen human pituitary glands by salt/ethanol fractionation, Sephadex G-75 gel filtration and DEAE- and cM-cellulose ion-exchange chromatography. The peptide is glycosylated, has an N-terminal tryptophan residue and an apparent mol.wt. of 16000 as estimated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. Its amino acid analysis closely resembles residues Trp-105 to Gln-29 predicted for the common precursor protein of bovine corticotropin and beta-lipotropin by Nakanishi, Inoue, Kita, Nakamura, Chang, Cohen & Numa [(1979) Nature (London) 278, 423-427]. This fragment is expected to have melanotropin activity due to the tetrapeptide -His-Phe-Arg-Trp- (residues -51 to -48) of the predicted sequence of the common precursor. It was found to have a molar potency of 1 X 10(-5) relative to alpha-melanotropin in the frog skin bioassay. These characteristics are consistent with the isolated melanotropin peptide being a non-corticotropin, non-lipotropin peptide of the human common precursor protein of corticotropin and lipotropin. The peptide neither potentiates the adrenal weight-maintenance activity of corticotropin-(1-24)-tetracosapeptide when administered to hypophysectomized rats, nor stimulates release of non-esterified fatty acids from isolated rat epididymal cells. A second N-terminal-tryptophan glycopeptide was also isolated, which had an amino-acid composition similar to that predicted for the bovine common precursor protein, residues Trp-105 to Gly-35.
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PMID:Purification and characterization of a gamma-melanotropin precursor from frozen human pituitary glands. 747 89

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

The synthetic C-terminal peptide fragment of human growth hormone, Leu-Arg-Ile-Val Gln-Cys-Arg-Val-Ser-Glu-Gly-Ser-Cys-Gly-Phe (hGH 177-191), was shown to have antilipogenic activity identical with that of the intact molecule of human growth hormone (hGH). No significant lipolytic effect of hGH 177-191 was found as determined by the rate of glycerol release from epididymal fat pads of the peptide-treated rats. The results support the suggestion that the functional domain responsible for the antilipogenic activity of hGH resides in the C-terminal region of the molecule and that the main physiological effect of hGH in lipid metabolism is at the level of lipogenesis.
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PMID:Antilipogenic action of synthetic C-terminal sequence 177-191 of human growth hormone. 835 31

The effect of three nitric oxide (NO) synthase inhibitors, L-NG-nitro-arginine (NO2Arg), NG-Nitro-L-arginine methyl ester (L-NAME) and aminoguanidine, on in vitro fertilization in the mouse was examined. Mouse epididymal spermatozoa were capacitated in a medium with or without NO synthase inhibitors. Oocytes were inseminated and the percentage of oocytes with two pronuclei was scored after an 8-h incubation. NO2Arg and L-NAME, but not aminoguanidine, inhibited fertilization. L-NAME inhibited fertilization in a dose-dependent manner, and its effects were stereospecific. The inhibitory effect was neutralized by L-arginine but not by D-arginine. Moreover, D-NAME did not inhibit fertilization. The results suggest that NO synthase activity (presumably of the constitutive type is necessary for spermatozoa to display their full fertilizing ability.
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PMID:Effects of nitric oxide synthase inhibitors on the outcome of in vitro fertilization in the mouse. 872 70

A protein designated as BE-20 was purified from cauda epididymal fluid of the rabbit by preparative polyacrylamide gel electrophoresis and HPLC on a mono Q HR5/5 anion exchange column. The purified protein migrated with an estimated Mt of 20,000 when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The amino acid sequence of the N-terminus of the BE-20 protein was determined. The initial eight amino acid residues were His-Gly-Ala-Asp-Lys-Pro-Gly-Val. The corresponding 23 mer oligonucleotide (5'-CATGGCGCTGACAAGCCTGGGGT-3') was synthesized and used as sense primer with rabbit epididymal mRNA as template in the RT-PCR system. The purified BE-20 cDNA consisted of 499 bp with an open reading frame of 285 bp encoding a deduced polypeptide composed of 95 amino acids. The BE-20 cDNA had 78.5% identity in 479 bp overlap with human epididymis-specific HE4 cDNA. The amino acid sequences of the initial 30 amino acid residues of the N-terminus of the purified protein and the deduced polypeptides were as follows: N-His-Gly-Ala-Asp-Lys-Pro-Gly-Val-Cys-Pro-Gln-Leu-Ser-Ala-Asp-Leu-Asn-Cy s- Thr-Gln-Asp-Cys-Arg-Ala-Asp-Gln-Asp-Cys-Ala-Glu. The deduced polypeptide contained 16 cysteine residues and had partial sequence homology with proteins belonging to the four-disulfide core family of extracellular proteinase inhibitors. The BE-20 protein may play a role in sperm maturation and/or capacitation.
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PMID:Identification of a rabbit epididymal protein gene. 888 63

Binding of mammalian spermatozoa to the zona pellucida of homologous eggs is mediated by specific molecules on their surface membranes. In the present investigation we describe the biogenesis, epididymal processing and cellular distribution of a plasma membrane antigen (2B1) on rat spermatozoa that has a potential role in mediating zona binding. 2B1 is expressed postmeiotically in the testis as a precursor glycoprotein (approximately 60 kDa) that first appears on the plasma membrane of stage 6 to 8 round spermatids. Northern and western blot analyses show that there is a close correlation between the timing of transcription and expression of the glycoprotein on the cell surface. During spermatid elongation 2B1 is excluded from the head domain and is sequestered onto the sperm tail. As spermatozoa pass through the caput epididymidis 2B1 is endoproteolytically cleaved at a specific arginine residue (Arg 312) to produce a heterodimeric glycoprotein (approximately 40 kDa and approximately 19 kDa) containing intramolecular disulphide bridges. Endoproteolysis at Arg 312 also takes place during culture of washed testicular or caput spermatozoa in vitro and can be prevented by serine proteinase inhibitors or enhanced by trypsinisation. However, neither processing in vivo or in vitro has any effect on the domain organisation of 2B1 antigen i.e. it remains localised to the tail. These results support the hypothesis that sperm antigens that are important for fertilization are synthesized as precursor molecules in the testis and are then "activated' during epididymal maturation and capacitation, thereby ensuring that they only become fully functional at the site of fertilization.
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PMID:Testicular biosynthesis and epididymal endoproteolytic processing of rat sperm surface antigen 2B1. 892 17

cAMP is important for the initiation of mammalian sperm motility. Previously we established that a type II cAMP-dependent protein kinase is tightly associated with the fibrous sheath of rat sperm. This unique cytoskeletal structure surrounds the 9+2 axonemal network in the principal piece of the flagellum. Association of the kinase to the fibrous sheath is mediated via its regulatory subunit, RII. An RII-binding overlay procedure was used to document that RII could specifically associate with fibrous sheath polypeptides of 120 and 80 kDa. In this study, we report the cloning of a rat testis-specific, developmentally regulated, RII-binding protein (TAKAP-80). A 1.2-kb cDNA clone, isolated by screening a rat testis expression library with 32P-labeled RII, hybridized to a 1.8-kb mRNA transcript present exclusively in testis. This transcript appeared at detectable levels at 30 days after birth. Over the next 10 days the mRNA levels increased greatly. This time interval corresponds to the initiation of spermiogenesis. The complete nucleotide sequence of TAKAP-80 cDNA was obtained by polymerase chain reaction and contained a continuous open reading frame of 502 amino acids. The deduced amino acid sequence showed a clear demarcation of charged and hydrophobic amino acid residues. Amino acids 1-147 of the protein contained 45% charged residues, with lysine and arginine predominating. Similarly, amino acids 268-502 also contained a high percentage of charged amino acids (35%). In contrast, amino acids 148-267 were mostly hydrophobic and contained clusters of a repeating PXXP motif where X was predominantly valine and alanine or sometimes proline. The 1.2-kb cDNA clone was inserted into the pRSET vector and expressed as a His6 tag fusion protein in Escherichia coli. The recombinant protein was soluble and bound RIIalpha, RIIbeta and type IIalpha holoenzyme by the RII-binding overlay procedure. Deletion analysis revealed that the high-affinity interaction site for RII was contained within amino acids 258-378 of TAKAP-80. Antibodies prepared against the fusion protein recognized an 80-kDa protein present in the urea-insoluble particulate fraction of rat testis and in purified fibrous sheath preparations isolated from rat epididymal sperm. Levels of the 80-kDa immunoreactive protein were significantly higher in mature (60 days old) compared with immature (30 days old) rat testis, correlating with the mRNA levels.
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PMID:Cloning and characterization of a testis-specific, developmentally regulated A-kinase-anchoring protein (TAKAP-80) present on the fibrous sheath of rat sperm. 920 34


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