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

alpha 1-Acid glycoprotein (AGP) was purified to homogeneity by a 3-step procedure using pseudo-ligand affinity chromatography on immobilized Cibacron blue F3GA, Procion red HE3B, and preparative column isoelectric focusing. The overall yield of the combined techniques was 88%. Analysis of the purified AGP by lectin affinity chromatography on immobilized Con A and immunoaffino-electrophoresis indicated that the most acidic form did not interact with the lectin, while the two more basic fractions possessed different affinities for Con A. In addition, 3 different populations of AGP were clearly separated by Con A affinity chromatography.
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PMID:A three-step purification of human alpha 1-acid glycoprotein. 670 25

Acidic epididymal glycoprotein (AEG) and androgen-binding protein (ABP) antisera were used to study functional activities of primary cell cultures of the epididymal epithelium of 20--23-day-old rats. Extensive AEG immunoreactivity was associated with almost all epithelial cells of the distal caput, corpus and cauda epididymidis. ABP immunoreactivity was solely confined to some epithelial cells of the caput epididymidis. AEG and ABP immunoreactive cells were identified as principal cells. Morphological studies of enzymically dispersed aggregates of the epididymal epithelial cells showed that stromal cells were satisfactorily removed and that cell aggregates consisted of a predominant population for cells displaying the morphological characteristics of principal cells. Scanning and transmission electron microscopic studies of cultured epididymal epithelial cells in monolayers demonstrated that microvilli and pit-like invaginations of the cell surface were preserved during the first 7--10 days of culture and then gradually disappeared. Other characteristic subcellular structures such as Golgi apparatus and rough endoplasmic reticulum cisterna were preserved. Electrophoretic analysis of [35S]methionine-labelled secretory polypeptides released by epididymal epithelial cells into the culture medium demonstrated a distinct protein band pattern which differed from that observed in the medium of cultured rat Sertoli cells. These results demonstrate that primary cultures of epididymal epithelial cells isolated from sexually immature rats maintain several differentiated characteristics of the intact organ and therefore provide a valuable system for the study of epididymal epithelial cell function.
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PMID:Structural and functional aspects of cultured epididymal epithelial cells isolated from pubertal rats. 675 17

A soluble aspermatogenic autoantigen (AP2) capable of inducing experimental allergic orchitis (EAO) in the guinea pig has been isolated from the soluble acrosomal contents (SAC) released from guinea pig cauda epididymal sperm during the in vitro Ca+2 ionophore A23187-induced acrosome reaction. AP2 purification was achieved by heat inactivation of SAC enzymatic activity, followed by chaotropic solubilization and ultracentrifugation, gel filtration on Sephadex G-50, preparative isoelectric focusing, and SDS-polyacrylamide gel electrophoresis. Approximately 80 micrograms of AP2 was obtained from 1 to 2 x 10(10) cauda epididymal sperm. AP2 has a m.w. of 9500 +/- 1500 as determined by unreduced SDS-PAGE and an isoelectric point of 5.52 +/- 0.11. Amino acid analysis of AP2 indicates that it is a protein. AP2 has no detectable hexose or hexosamine as determined by gas liquid chromatographic analysis and is therefore probably not a glycoprotein. Five micrograms of AP2 are capable of inducing severe EAO in 100% of guinea pigs tested, whereas 0.5 to 2.0 micrograms induces mild lesions consisting primarily of aspermatogenesis in 66% of guinea pigs tested.
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PMID:Acrosomal autoantigens of guinea pig sperm. I. The purification of an aspermatogenic protein, AP2. 684 85

The secretory activity of the middle segment of the mouse caput epididymidis was studied using 3H-fucose as a precursor to glycoprotein. Young adult male mice were injected with a concentrated solution of 3H-fucose interstitially, ie beneath the connective tissue capsule of the epididymis. Two animals were killed and prepared for light microscopic radioautography at each of six intervals between 10 minutes and 24 hours after injection. Silver grains were concentrated over the supranuclear Golgi region at 10 minutes and over the apical ends of the cells 30 minutes and 1 hour after injection. Quantitative analysis showed that luminal radioactivity increased greatly beginning with the 2-hour samples. The results indicate that the epididymal epithelium synthesizes and secretes glycoproteins, and that 1 to 2 hours are required for terminal glycosylation, intracellular transport, and release of the secretory product.
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PMID:Synthesis and secretion of glycoprotein by the epididymal epithelium. 685 61

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

Previous results demonstrated that androgen-dependent rat specific epididymal proteins (SEP) were bound to spermatozoa during their maturation in the epididymis. This paper describes the purification of glycoprotein DE, which constitutes 40% of SEP, and the identification and semiquantitative determination of the sugars forming its oligosaccharide chain. Affinity chromatography on Sepharose-Concanavalin A produced a sample of D-E 95% pure in which 10.5 g of sugar were present per 100 g protein. The percentual composition of the oligosaccharide was D-mannose 19%; D-galactose 3%; N-acetyl-D-glucosamine 33%; N-acetyl-neuraminic acid 31% and D-glucose 13%.
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PMID:Carbohydrate composition of specific rat epididymal protein. 716 Sep 23

Mature male rabbits and hamsters were bilaterally castrated and their epididymides were examined, at 2, 4, 7, 9 and 14 days after operation, for the presence of several glycoproteins by using monospecific antisera and indirect immunoperoxidase labelling. In the rabbit, there was a reduction in the glycoprotein reaction product in the epithelium of the proximal caput epididymidis by 2-4 days after castration, and the staining was weak or absent by 7-9 days. Compared with controls, there was also a marked decrease in the intensity of reaction product to glycoprotein in the lumen of the proximal and distal corpus epididymidis 2-4 days after castration although spermatozoa still filled the duct in this region. Glycoprotein was present in the distal cauda epididymidis at 14 days but staining diminished as spermatozoa were cleared from the tract. In the hamster, epididymal glycoproteins were apparently less critically dependent on androgens than those in the rabbit, reaching a weak but constant level in the proximal region by 7-9 days after castration and remaining at the same intensity in the distal cauda epididymidis throughout the study. These results suggest that the secretion of specific glycoproteins by the mammalian epididymis is related to androgen levels and to sperm maturation.
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PMID:Effects of castration on specific glycoprotein secretions of the epididymis in the rabbit and hamster. 720 80

To assess the functional significance of glycoprotein secretions of the rabbit and hamster epididymis during sperm maturation and fertilization, antibodies have been raised against acidic protein fractions isolated from epididymal fluid. Specific antiserum was elicited against each of three rabbit glycoproteins designated R1, R2, and R3 with isoelectric points of pI 3.45, 4.15, and 4.65 respectively, and against one hamster glycoprotein (Hl), pI 3.40. Epididymal glycoproteins on the surface of washed spermatozoa from various regions of the epididymis were localized by the fluorescent antibody technique and by sperm agglutination with antiserum. They were first detected on restricted regions of spermatozoa from the distal caput and corpus epididymidis and each antigen had a characteristic binding pattern. The effect of specific antibodies on fertilization in vivo was tested in rabbits by preincubating cauda epididymal spermatozoa with heat-treated antiserum or univalent immunoglobulin fragments before their deposition into oviducts of does induced to ovulate. In all cases, fertilization rates were significantly reduced (P less than or equal to 0.05) compared with controls, the most effective antiserum being against glycoprotein antigen R1 found only on the anterior acrosome of spermatozoa. Heat-treated antiserum against H1 glycoprotein placed in the bursal cavity of ovulating females significantly inhibited fertilization in the hamster (P less than or equal to 0.005). These results are discussed in relation to the modification to the sperm plasmalemma during maturation.
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PMID:Glycoprotein secretions of the epididymis in the rabbit and hamster: localization on epididymal spermatozoa and the effect of specific antibodies on fertilization in vivo. 722 99

An acidic protein which is secreted by epididymal epithelial cells, has been characterized with respect to physiochemical properties. Acidic epididymal glycoprotein is a glycoprotein of molecular weight of 31 700. It is apparently a symmetrical molecule (f/f0 = 1.26) composed of a single polypeptide chain. Carbohydrate content is 7.5% and consists mainly of hexoses (73%). Acidic epididymal glycoprotein is rich in aromatic amino acids although its content of hydrophobic amino acids (50.9%) and average hydrophobicity (1053 cal/residue) is unexceptional. The acidic nature of acidic epididymal glycoprotein is consistent with a high content of aspartic and glutamic acid (27.5%), a high fractional charge (0.37) and a low isoelectric point (pI = 4.7). Acidic epididymal glycoprotein appears to bind to spermatozoa during epididymal transit and may thus increase the negative charge on the sperm plasma membrane. An increase in anodic mobility is a characteristic change associated with sperm maturation and implies a role for acidic epididymal glycoprotein in this process.
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PMID:Characterization of an acidic glycoprotein secreted by principal cells of the rat epididymis. 723 13

Boar rete testis fluid and luminal contents from nine epididymal segments were collected for analysis. From proximal to distal, segments were designated A, B, C (caput), Da, Db, Ea (corpus) and Eb, Fa, Fb (cauda). Concentrations of sperm, protein and soluble sperm membrane glycoprotein S2P3 were lowest in the caput epididymidis (region A) and highest in the proximal corpus epididymidis (region Da). At region Da, approximately 94% of the fluid that had entered the epididymis had been reabsorbed. More total protein was found in the luminal fluid of region Da than could be accounted for on the basis of concentration via fluid removal. The proximal cauda epididymidis was the major luminal protein-removing region. However, large amounts of glycoprotein S2P3 were removed from the luminal fluids during passage through the caput epididymidis, and smaller amounts were removed during passage through the cauda epididymidis.
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PMID:Concentrations of sperm, protein and a sperm membrane glycoprotein within boar epididymal luminal fluids. 726 31


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