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 protein of neurite outgrowth activity has been identified in porcine seminal plasma after ammonium sulfate precipitation and affinity chromatography on heparin-Sepharose. Upon SDS-PAGE, the polypeptide is shown to have a M(r) of 16,000-18,000. Biologically by induction of neuritic processes on neuroblastoma cells, and immunologically by cross-reaction with specific antisera, this seminal plasma protein differs from acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF) and nerve growth factor (NGF). The neurite outgrowth activity is relatively stable at pH 3-7 and under denaturing conditions of 8 M urea and beta-mercaptoethanol, but is inactivated by treatment of trypsin. This appears to be a novel protein, enhancing morphological differentiation of neuroblastoma cells in culture.
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PMID:A heparin-binding protein in porcine seminal plasma stimulates neurite outgrowth on neuroblastoma cells in culture. 138 97

Horse seminal plasma does not possess a proteinase inhibitor corresponding to human HUSI-I (human seminal plasma inhibitor). Instead a protein complex of high relative molecular mass (Mr) containing proteinase inhibitory activity was detected, which was called horse seminal plasma protein complex or HSPC. The compound had a broad enzyme-inhibiting spectrum. Its Mr was estimated to be 800 000 and it was composed of 7 different polypeptides with Mr values ranging from 11 000 to 30 000. Its carbohydrate content was between 3.5% and 5%. Despite the high molecular mass, the complex was soluble in diluted perchloric acid and did not lose its biological activity. The high recovery of seminal plasma protein (69%) after perchloric acid treatment, the unaltered immunoelectrophoretic precipitation pattern of the perchloric acid soluble part of seminal plasma, and the similarity of the polypeptide patterns of unfractionated seminal plasma and HSPC suggest that HSPC is one of the major components of horse seminal plasma. In addition to HSPC, horse seminal plasma contained a group of three electrophoretically distinguishable proteinase inhibitors, corresponding roughly to a Mr of 6500. They inhibited only trypsin. The similar Mr values and the identical narrow enzyme specificity suggest that they are isoinhibitors and may be analogues of human HUSI-II (human seminal plasma inhibitor). The lack of a HUSI-I analog in the horse is discussed in relation to a previously made observation that horse tracheobronchial fluid contains no detectable perchloric acid-soluble proteinase inhibitors.
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PMID:Proteinase inhibitors of horse seminal plasma. A high molecular mass, acid-soluble proteinase inhibitor. 299 13

The complete amino acid sequence of beta-microseminoprotein of human seminal plasma was determined by automated Edman degradation of the protein and peptides which were obtained by enzymatic cleavage with trypsin, chymotrypsin and Staphylococcus aureus V8 proteinase. The carboxyl-terminal sequence of the protein was established with the aid of carboxypeptidase A. The amino acid sequence of this protein proved to be as follows: (sequence; see text) Thus, beta-microseminoprotein consisting of 93 amino acid residues has a molecular mass of 10 652 Da. The linear structure of this protein represents the first complete amino acid sequence of a sperm-coating protein specific to human seminal plasma.
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PMID:The amino acid sequence of human beta-microseminoprotein. 399 56

To clarify the co-expression phenomenon of T-cell Fc receptors (FcR) specific for different isotypes on the clonal level, a murine hybridoma clone T2D4 was studied. T2D4 cells originally reported to bear FcR for IgG (Fc gamma R) and to release a Fc gamma R-related T-cell factor binding to IgG (immunoglobulin binding factor; IBF) proved to have also the receptor for IgA. The binding of IgA was detected by rosette formation with trinitrophenylated ox red blood cells (TNP-ORBC) after preincubation of T2D4 cells with MOPC 315 IgA having anti-TNP activity, or directly with TNP-ORBC sensitized with MOPC 315 IgA. While the binding of MOPC 315 IgA was competed for by IgA but not by IgG2A nor IgG2B, IgA failed to inhibit the rosette formation of the cells with ORBC sensitized with rabbit IgG antibody (EA ox gamma), proving that T2D4 cells express FcR specific for IgA (Fc alpha R) in addition to Fc gamma R. Co-expression of both receptors on the same cell surface was demonstrated by a double rosette technique using TNP-quail red blood cells (TNP-QRBC) and EAox gamma. Fc alpha R activity of the cells was completely abrogated by 15 min. incubation with 0.1 mg/ml trypsin, whereas Fc gamma R was resistant even to 1 mg/ml trypsin. The expression of Fc alpha R was augmented (up-regulation) by IgA at the concentration above 300 micrograms/ml and inhibited (down-regulation) by 1000 u./ml of murine beta-interferon (beta-IFN). Conversely, the expression of Fc gamma R was down-regulated by IgA and up-regulated by alpha-IFN. Thus, Fc gamma R and Fc alpha R are co-expressed and reciprocally regulated on these cell lines. The possible co-production of IBF and the Fc alpha R-related binding factor specific for IgA is discussed.
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PMID:T-cell hybridoma co-expressing Fc receptors for different isotypes. I. Reciprocal regulation of Fc alpha R and Fc gamma R expression by IgA and interferon. 621 65

We have analyzed protein patterns of human nasal lavage fluid (NLF) with two-dimensional gel electrophoresis (2-DE) and identified several proteins (such as transthyretin, Clara Cell protein 16, lipocalin-1, cystatin S, cystatin SN, immunoglobulin binding factor, statherin, calgranulin B, prolactin-inducible protein, and zinc-alpha2-glycoprotein) by N-terminal amino acid sequencing and matrix-assisted laser desorption/ionizationtime of flight (MALDI-TOF) mass spectrometry. To investigate whether airway irritation causes alterations in NLF 2-DE patterns, we compared epoxy workers with airway irritation (n=8) and healthy controls (n=6) before and after 2 h exposure to the epoxy chemical, dimethylbenzylamine (DMBA, 100 microg/m3) in an exposure chamber. A 25 kDa protein with pI 5.5 was found to be altered in the NLF 2-DE patterns; a trypsin digest of the 2-DE spot analyzed by MALDI-TOF and expressed sequence tags (ESTs) determined after post-source decay (PSD) identified the protein as palate lung and nasal epithelial clone (PLUNC). In controls, the levels of NLF-PLUNC were generally lower after 2 h exposure, whereas in epoxy workers, the levels were increased three- to twentyfold after exposure. The human gene sequence for PLUNC was just recently reported and so far no biofunctional data are available. Our results suggest that PLUNC is involved in the airway inflammatory response after exposure to irritants.
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PMID:Identification of a new potential airway irritation marker, palate lung nasal epithelial clone protein, in human nasal lavage fluid with two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time of flight. 1142 34

The objective of this study was to evaluate the low weight (10-30 kDa) protein profile of bovine seminal plasma using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and to determine if any of these proteins was associated with semen freezability. Seminal plasma was collected from 16 bulls of high or low semen freezability. Twelve protein spots were identified from the 2D gel (15%); six of these were present in all samples. Of the 12 proteins found, three spots, present in all samples, 3 (15-16 kDa), 5 (16-17 kDa), and 7 (10-12 kDa) had nonsignificant variation among bulls, regardless of their freezability classification. Four proteins were more abundant (P<0.05) in seminal plasma samples collected from bulls with high semen freezability than in samples of bulls with low semen freezability: the spots 3 (15-16 kDa, pI 4.7-5.2), 7 (11-12 kDa, pI 4.8-4.9), 11 (13-14 kDa, pI 4.0-4.5), and 23 (20-22 kDa, pI 4.8-5.2). On the other hand, spot 25 (25-26 kDa, pI 6.0-6.5) was more abundant (P<0.05) on seminal plasma samples from bulls with low semen freezability. The N-terminus sequence of protein 7 was identical to the acidic seminal fluid protein (aSFP). Protein 23 (after trypsin digestion) had structural similarity to bovine clusterin. We concluded that there were differences in the seminal plasma protein profile from bulls with low and high semen freezability; aSFP, clusterin, proteins 3 and 11 may be used as semen freezability markers; and protein 25 was related to low semen freezability.
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PMID:Two-dimensional polyacrylamide gel electrophoresis of bovine seminal plasma proteins and their relation with semen freezability. 1466 26

The aims of the study were: 1/ to isolate and identify equine seminal plasma proteinase inhibitors, 2/ to evaluate their inhibitory potential, and 3/ to test a correlation between protein concentration in seminal plasma supernatant (obtained after precipitation with 36% ammonium sulfate) and stallion sexual maturity. Seminal plasma proteins obtained from six stallions were chromatographed in a Superose 12 (FPLC system) column followed by C(18) HPLC reverse-phase. Inhibition of trypsin amidase activity was evaluated in the collected fractions. Active proteins with a molecular mass of 6.3-7.0 KDa were identified using mass spectrometry. The older stallions showed a reduction in total seminal plasma protein concentration, but had similar concentrations of proteinase inhibitors (0.28+/-0.10 mg/ml) in seminal plasma supernatant. Different proteinase inhibitor isoforms were found in semen of all stallions which suggests that the isoforms may be used as biomarkers of individual animals.
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PMID:Purification and partial characterization of proteinase inhibitors of equine seminal plasma. 1973 53