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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of trypsin inhibitors and phospholipase inhibitors on the acrosome reaction of washed cauda epididymal sperm of golden hamsters were studied using two different incubation systems. One incubation system, a non-synchronous acrosome reaction inducing system, included the use of a highly purified BSA and a protein-free motility factor preparation from hamster adrenal gland. The other system was a relatively synchronous acrosome reaction-inducing-system utilizing the calcium ionophore A23187. Acrosome reactions were inhibited by three low molecular weight synthetic trypsin inhibitors, benzamidine, NPGB and TLCK, when they were added five minutes prior to the initial occurrence of acrosome reactions in the non-synchronous system or five minutes prior to induction of acrosome reactions by A23187 in the synchronous system. Two phospholipase A inhibitors, p-bromophenacyl bromide and mepacrine, were also effective in inhibiting hamster sperm acrosome reactions in both incubation systems. TPCK, an inhibitor of several non-trypsin-like proteases, indomethacin, a prostaglandin synthetase inhibitor, and soybean trypsin inhibitor, a large molecular weight polypeptide, did not inhibit acrosome reactions. The inhibition of those acrosome reactions induced by A23187 provides further indirect evidence that the effective inhibitors were functioning at a site within the sperm. The overall results provide: (1) further support for our earlier work suggesting the involvement of an internal trypsin-like enzyme (presumably acrosin) rather than an exogenous trypsin-like enzyme in the hamster sperm acrosome reaction and (2) the first evidence suggesting the possibility that a sperm phospholipase may also be involved in the mammalian acrosome reaction.
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PMID:Further evidence in support of a role for hamster sperm hydrolytic enzymes in the acrosome reaction. 57 94

An androgen affinity column was synthesized by covalently linking 3-oxo-17beta-hydroxy-5alpha-androstan-17alpha-(6-hexanoic acid) to cyanogen bromide activated Sepharose through a dipropyldiamine side arm. This column was designed to recover androphilic proteins from homogenates rich in nonspecific esterases. An extract of rat epididymis was adsorbed on the affinity column after partial purification by ammonium sulfate precipitation. The column was washed with 1 M KCl and the androgen binding protein eluted with 17beta-hydroxy-5alpha-androstan-3-one resulting in a 1,100-fold increase in specific activity. This protein had the same mobility on polyacrylamide gels and the same estimated molecular weight (135,000 daltons by gel filtration) as androgen binding protein in the original extract. By contrast, electrophoresis on sodium dodecyl sulfate containing gels yielded 2 bands with estimated molecular weights of 42,000 and 47,000 daltons. These observations are consistent with a subunit structure for rat epididymal androgen binding protein.
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PMID:A novel affinity column for isolation of androgen binding protein from rat epididymis. 89 61

Conditions are described that permit the quantitative extraction of chromatin proteins from the epididymal sperm of the mouse. These proteins have been isolated free of contaminating tail proteins following removal of the tails with cetyltrimethylammonium bromide (CTAB). Without this treatment, numerous acid-soluble tail proteins coextract with the nuclear proteins isolated from partially purified heads. The proteins isolated in this manner do not require prior modification with iodoacetamide and show no evidence of proteolytic degradation. In acid-urea polyacrylamide gels, 99% of the sperm protein migrates as one electrophoretic band. Evidence is presented that suggests that this single band contains two protamine-like proteins.
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PMID:Mouse sperm chromatin proteins: quantitative isolation and partial characterization. 91 55

A general assay for plasma membrane stability was developed and tested. Osmotically swollen spermatozoa were ruptured with detergents and their volume distribution was monitored with resistance pulse spectroscopy. The extent of cell breakage was determined and expressed as [D]50, the concentration of detergent necessary to lyse 50% of the initially intact cells. Preliminary experiments established the degree to which spermatozoa could be swollen without lysis (no detergent) and the ability of the method to detect known mixtures of intact and membrane disrupted spermatozoa. [D]50 values were determined for caput (immature) and cauda (mature) ram epididymal spermatozoa with four detergents (cetyltrimethylammonium bromide, sodium dodecylsulfate, Zwittergent 3-14, and sodium deoxycholate). [D]50 values for caput spermatozoa were higher than those for cauda spermatozoa (P less than 0.05) for all detergents but cetyltrimethylammonium bromide. These changes are consistent with a qualitative model of membrane structure and stability based on lipid shape and composition and with the compositional changes known to occur during epididymal maturation. Additional studies using rooster spermatozoa established that a typical cryopreservation protocol leaves the surviving spermatozoa with membranes with greater sensitivity to detergent-induced stress. Since osmotic swelling has been microscopically localized to the tail plasma membrane, the changes in membrane stability can be assigned specifically to that region.
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PMID:Evaluation of plasma membrane stability by detergent-induced rupture of osmotically swollen sperm. 156 Jan 84

Several lines of evidence have demonstrated conclusively the presence of cAMP-dependent protein kinase (ecto-RC) activity on the external surface of goat cauda-epididymal intact spermatozoa. The intact-cell ecto-kinase that caused transfer of the terminal phosphate of exogenous ATP to the serine and threonine residues of exogenous histone was specifically activated by cAMP. As well, the ecto-kinase caused phosphorylation of the synthetic peptide Kemptide. The isolated spermatozoa, before or after incubation with reaction mixture for ecto-kinase assays, were approximately 99.5% viable, as shown by the analyses of ethidium bromide fluorescence and the cytosolic marker enzymes lactic dehydrogenase and 3-phosphoglycerate kinase. The ecto-kinase activity was not due to contamination of epididymal plasma and damaged cells or to protein kinase that may have leaked from the cells. There was little uptake of ATP and histone by the cells. The intact-cell kinase activity was strongly (80-90%) inhibited by treatment with membrane nonpenetrating surface probes: p-chloromercuriphenylsulfonic acid (2 microM), diazonium salt of sulfanilic acid (DSS, 0.5 mM), and proteases such as trypsin, chymotrypsin, and pronase (each 125 micrograms/mL). Disruption of sperm plasma membrane by sonication or Triton X-100 (0.2%) caused about a fivefold increase of the intact sperm kinase activity. Highly purified sperm plasma membrane (PM) possessed ecto-kinase activity that was resolved into type I and II kinases by DEAE-cellulose chromatography, the type I isoenzyme being the major (approximately 70%) enzymic species. Treatment of the intact spermatozoa with DSS prior to isolation of PM caused a marked loss of the activities of both the isoenzymes, indicating thereby the "ecto" nature of the PM-bound type I and II kinases. Preparations of vigorously forward-motile spermatozoa with 100% intactness had approximately fourfold higher specific activity of the ecto-kinase than the "composite" cells from which the former cells were isolated. However, the profiles of the type I and II ecto-kinases of the composite, as well as forward-motile spermatozoa, were nearly identical. The data are consistent with the view that ecto-kinases may have role in the regulation of flagellar motility.
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PMID:Type I and II cAMP-dependent ecto-protein kinases in goat epididymal spermatozoa and their enriched activities in forward-motile spermatozoa. 216 Aug 33

An improved Ficoll density gradient centrifugation method has been described for the isolation of goat caput-epididymal immature spermatozoa of a high purity and intactness. The method consists of layering freshly extracted sperm suspension on the top of a Ficoll gradient comprising 2.5 ml each of 2%, 4%, 6%, and 8% Ficoll-400 in a modified Ringer's solution and centrifugation at 300 g for 3 min in a swing bucket table centrifuge. Spermatozoa, free from fat globules and blood cells, sedimented at the bottom of the 8% Ficoll layer. The plasma membrane of the isolated cells showed a high degree of intactness (approximately 96%) as assessed by lactic dehydrogenase marker enzyme and ethidium bromide-fluorescence methods.
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PMID:Ficoll gradient isolation of immature sperm of high purity and intactness from goat epididymis. 232 22

By using ethidium bromide fluorescence to measure cellular permeability and the photoaffinity probe, 8-azido-[32P] cyclic adenosine monophosphate (cAMP), to label cAMP-dependent protein kinases, washed bovine epididymal spermatozoa were examined for the presence of "ectokinases" on the sperm surface. In washed, intact spermatozoa, three proteins of Mr 49,000, 54,000, and 56,000 specifically bound 8-azido-[32P] cAMP. The Mr 49,000 protein corresponded to the type I regulatory subunit while the Mr 56,000 and 54,000 proteins comigrated with phosphorylated and dephosphorylated forms, respectively, of type IIA regulatory subunit of bovine heart. The addition of Nonidet P-40 (0.1%) increased the radioactive labeling of all three proteins and caused the appearance of a cAMP binding protein of Mr 40,000, which was likely a proteolytic fragment of the regulatory subunit. Although these data could support the concept of a surface location for regulatory subunits in spermatozoa, it was necessary to determine if the appearance of cAMP binding sites was correlated with the loss of membrane integrity. A population of washed epididymal spermatozoa appeared to contain 10-20% damaged cells based on ethidium bromide fluorescence. The same population of cells also had 10-20% of the regulatory subunits of the cAMP-dependent protein kinase accessible to labeling with the cyclic AMP photoaffinity probe. When spermatozoa were sonicated for increasing lengths of time, ethidium bromide fluorescence was found to be related directly to the relative amount of regulatory subunit labeling by the probe. It is suggested that the major apparent cAMP-dependent "ectokinases" in sperm represent artifacts resulting from cellular damage.
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PMID:Cyclic AMP-dependent protein kinase isozymes of bovine epididymal spermatozoa: evidence against the existence of an ectokinase. 301 Nov 34

A quantitative method based on fluorescence generated by the binding of ethidium bromide (EB) to DNA has been developed for estimation of the intactness of the plasma membrane of a mammalian cell type (goat epididymal spermatozoon). The method consists of mixing of sperm preparations with EB in a modified Ringer's solution followed by immediate measurement of fluorescence intensity at 365-580 nm (excitation-emission). The data were corrected for non-specific values of fluorescence due to intact cells only. The percentage of damaged cells in a sperm population was calculated by comparing the corrected fluorescence values of the cell preparations with those of the sonicated cells. The values of sperm intactness obtained by this method (99.5 +/- 0.3) compared well with those obtained by the widely used "marker enzyme" method (97 +/- 0.8) based on estimation of lactic dehydrogenase in the extracellular medium. The validity of this method has been confirmed by using cells of defined intactness i.e. preparations of vigorously forward-motile spermatozoa that showed nearly 100% intactness. The method can detect as low as 0.5% "leaky" or damaged cells in a cell preparation. The "EB-fluorescence" method is simpler and more rapid and reliable than the conventional "marker enzyme" method for estimation of cellular intactness.
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PMID:A simple quantitative method of estimation of cell-intactness based on ethidium bromide fluorescence. 319 Jul 29

Methyl chloride (MeCl) and methyl bromide (MeBr) have similar target organ specificities in the male F-344 rat, and MeCl is a known reproductive toxicant in that species. Recently, both acute and subchronic inhalation exposures to MeBr were found to produce varying degrees of testicular alteration (S.L. Eustis, S.B. Haber, R.T. Drew, and R.S.H. Yang, 1986, Toxicologist, 6, 54; N. Kato, S. Morinobu, and S. Ishizu, 1986, Ind. Health, 24, 87-103; M.E. Hurtt, K.T. Morgan, and P.K. Working, 1987, Fundam. Appl. Toxicol., 9, 352-365). The present study examined the reproductive effects of MeBr in the male F-344 rat. Adult males (11-13 weeks) were exposed by inhalation to 0 or 200 ppm MeBr 6 hr/day for 5 days (first day of exposure = Day 1). Ten animals from each group were anesthetized with pentobarbital and terminated on Days 1, 3, 5, and 8. Additionally, five males from each group were killed on Days 6, 10, 17, 24, 38, 52, and 73. Plasma testosterone concentration was reduced during and immediately following exposure (Days 1, 3, 5, and 6), but returned to control levels by Day 8. Nonprotein sulfhydryl (NPSH) content of the liver and testis was reduced during exposure but returned to control levels by Day 8 (3 days postexposure). No other reproductive indices, including testis weight, daily sperm production, cauda epididymal sperm count, sperm morphology, percentage motile sperm, linear sperm velocity, and epididymal and testicular histology, were affected by MeBr exposure at any time point examined. Thus, although MeBr causes a transient decrease in plasma testosterone and testicular NPSH concentrations during acute exposure, it has no lasting effect on sperm quality or spermatogenesis in the F-344 rat.
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PMID:Evaluation of spermatogenesis and sperm quality in the rat following acute inhalation exposure to methyl bromide. 337 87

Treatment of caput or cauda epididymal rat sperm with a low concentration (0.05%) of the cationic detergent cetyltrimethylammonium bromide and 30 mM 2-mercaptoethanol solubilized most of the sperm structures except for the sperm head and the outer dense fiber-connecting piece complex. The latter were purified, and about 10% of these complexes are formed by nine fibers attached to the connecting piece. Of these fibers, two are shorter than the other seven and presumably correspond to fibers 3 and 8 (Fawcett, D.W. (1975) Dev. Biol. 44, 394-436). Electron microscopy confirmed the purity of the isolated outer dense fibers and revealed their characteristic irregular cross-sectional shape. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate showed six major polypeptides (Mr = 87,000, 30,400, 26,000, 18,400, 13,000, and 11,500) with a high content of serine, aspartic and glutamic acids, proline, cysteine, leucine, and tyrosine. Furthermore, several lines of evidence indicate a close structural relationship between the components of 30,400 and 26,000 Da. The six major components of the fibers are phosphorylated at serine residues. These results indicate that the major components of rat sperm outer dense fibers are a unique family of phosphoproteins.
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PMID:Polypeptide composition of rat sperm outer dense fibers. A simple procedure to isolate the fibrillar complex. 671 81


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