Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Receptors for [125I]hCG were found in adult human testis. The specific binding of [125I]hCG to testicular receptor is temperature dependent and is a saturable process with respect to added receptor protein and hormone. Scatchard analysis revealed a dissociation constant of 5.0 X 10(-10) M, and 6.2 fmol binding site/mg protein. Intact unlabeled hCG effectively inhibits the specific binding of [125I]hCG to human testicular receptors. For inhibition of binding of [125I]hCG, the alpha subunit has 3.0% of the potency of intact hCG and the beta subunit has 0.4% of the potency of intact hCG. Specific binding is pH dependent, with an optimum at pH 7.4. Brief exposure to extremes of pH causes irreversible damage to the receptors. Incubation with protease and trypsin results in an almost complete loss of binding activity, while ribonuclease, deoxyribonuclease, phospholipase C, or neuraminidase treatment does not significantly alter hormone-binding activity. Binding activity was found to be positively correlated to the concentration of intratesticular testosterone.
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PMID:Studies of the human testis. X. Properties of human chorionic gonadotropin receptor in adult testis and relation to intratesticular testosterone concentration. 23 73

Low concentrations of protease and trypsin reduced the electrophoretic mobility (EPM) of thymocytes; with higher concentrations it was normal or above. Differences in membrane structure of thymocytes, T and B cells was found as B cells showed no reduction while T cells gave intermediate values. Further the reduction was greater with protease than with trypsin. Formalin fixation increased the EPM of all normal cell types to a similar degree. The EPM of proteolytically treated thymocytes and B cells was increased to a similar level and to a greater degree than neuraminidase-treated thymocytes. Small amounts of sialic acid were detected in the supernatant after proteolytic treatment of thymocytes. Protease reduced the binding of anti-lymphocyte serum, while no definite effect was obtained with trypsin. Neither sublytic doses of phospholipase C nor ribonuclease appeared to change the EPM.
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PMID:Electrophoresis of lymphoid cells. Differences in the cell membrane structure of murine thymocytes, T and B cells revealed by enzyme and formalin treatment. 76 20

Nerve growth factor (NGF) receptor binding in membrane fractions of rabbit superior cervical ganglia has been measured after treatment with a variety of enzymes, protein-modifying reagents, and ions. Receptor binding is degraded by low concentrations of trypsin but is much less sensitive to alpha-chymotrypsin. Low concentrations of phospholipase A from Vipera russelli decrease NGF receptor binding by lowering the number of binding sites, while phospholipase A preparations from Crotalus terrificus terrificus and bee venom do not affect binding. Phospholipase C and D, neuraminidase, DNase, and RNase have minimal effects on receptor binding. NGF receptor binding appears to be absolutely dependent upon calcium ion. Removal of calcium from the incubation medium greatly reduces binding as does treatment with EDTA. Maximal receptor binding occurs at 5 mM calcium. Magnesium and sodium are unable to substitute for calcium. Receptor binding is greatly reduced by treating membranes with 2-hydroxy-5-nitrobenzyl bromide, 2-methoxy-5-nitrobenzyl bromide, diazonium tetrazole, and tetranitromethane. NGF receptor sites can be protected from 2-hydroxy-5-nitrobenzyl bromide by incubation with NGF.
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PMID:Nerve growth factor receptor binding. Influence of enzymes, ions, and protein reagents. 80 4

Exposure of mycobacterial growth inhibitory factor (MycoIF) to trypsin, chymotrypsin, or neuraminidase decrease its ability to produce intracellular inhibition of mycobacterial growth within macrophages, suggesting that MycoIF was a glycoprotein. MycoIF was unaffected by deoxyribonuclease or ribonuclease. Supernatant fluids from antigenically stimulated H37Ra-immunized mouse spleen cells exposed to puromycin were unable to produce significant intracellular inhibition. This indicated that the presence of MycoIF activity in supernatant fluids required protein synthesis. The filtration of MycoIF-containing supernatant fluids on Sephadex G-150 demonstrated that significant MycoIF activity appeared only in those fractions which eluted on the downward side of the serum albumin peak. Based on protein standards filtered through the Sephadex gel, the molecular weight of MycoIF was calculated to be between 20,000 and 35,000. These calculations assumed that MycoIF is a globular protein. Attempts to purify MycoIF by anion exchange chromatography (diethylaminoethylcellulose) was not successful.
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PMID:Molecular weight and other characteristics of mycobacterial growth inhibitory factor produced by spleen cells obtained from mice immunized with viable attenuated mycobacterial cells. 81 60

The bone inducing factor derived from BF osteosarcoma was purified in the following manner. Step 1. The sarcoma, grown in CBA mice, was excised and lyophilized. Step 2. The powder was washed with chilled acetone. Step 3. The acetone-treated powder was then homogenized with chilled distilled water. Step 4. Washing with 0.15M KCl. Step 5. The precipitate was incubated in in 0.2 N NH2OH, pH7.0, for 48 H at 25 degrees. After Step 5, the bone-forming activity showed a slight increase; however, the factor remained insoluble. The properties of the factor were as follows. The factor is relatively relatively heat stable; the osteogenic activity survived the treatment at 75 degrees for 15 min or at 55 degrees for 19 h. The activity was easily lost by mechanical shaking. Incubation with DNase, RNase, neuraminidase, chondroitinase ABC and beta-galactosidase left the osteogenic activity intact, but treatment with either pronase or collagnease destroyed this activity. The results suggest that the factor may be a protein. The activity was seen with the lyophilized BF osteosarcoma cells (without matrix), and it is probable that the factor was exclusively synthesized in the cells. The bone formation, observed across a millipore filter when living BF osteosarcoma enclosed in a millipore chamber was implanted in mice, suggests the synthesis and secretion of the factor from the cells.
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PMID:Studies on a factor responsible for new bone formation from osteosarcoma in mice. 105 58

The addition of trypsin [EC 3.4.21.4]-digested liver microsimes induced cyanideinsensitive respiration in guinea pig polymorphonuclear leucocytes with concomitant acceleration of the hexose monophosphate oxidative pathway. The respiration was insensitive to inhibitors of mitochondrial respiration but sensitive to glycolytic inhibitors. These metabolic alterations are similar to those associated with phagocytosis, though the digested mocrosomes were apparently not taken up by the cells and prpbably trigger the netabolic changes by interaction with the cellular membrane. Intact microsomes or microsomes treated with chymotrypsin [EC 3.4.21.1], bacterial proteinase, ribonuclease [EC 3.1.4.22], or neuraminidase [EC 3.2.1.18] could not induce such respiration.
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PMID:Metabolic pattern of polymorphonuclear leucocytes induced by trypsin-digested microsomes. 115 Jun 33

Changes of specific resistance and electrophoretic mobility of the cells from regenerative liver of rats are investigated. It is shown that specific resistance decreases and electrophoretic mobility increases during 30 h after hepathectomy. Exogenous ribonuclease decreases electrophoretic mobility by 10% and does not reduce significantly specific resistance. Neuraminidase treatment caused a marked increase (approximately 40%) of specific resistance without reduction in the mobility of cells from both intact and regenerative liver. It is concluded that there is no difference in the sensitivity of the cell surface of normal and regenerative liver to ribonuclease and neuraminidase.
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PMID:[Specific resistance and electrophoretic mobility of regenerating liver cells. Effect of ribonuclease and neuraminidase]. 125 13

The pattern of proteins in the soluble fraction of the cytoplasm of the rat epididymis was studied by acrylamide gel electrophoresis. The components of five distinct bands, labelled A, B, C, D and E, were found to be sensitive to changes in androgen in the blood. Castration for 14 days produced a sharp decrease in the colour intensity of bands B-E when stained with Amido black. After 21 days of castration, bands D and E were undetectable, bands B and C were severely diminished and band A was more intense. Seven days of replacement with testosterone (1 mg/day) induced a return towards a normal pattern. The degree of restoration was inversely proportional to the duration of castration. Quantitation by densitometry showed that the relative contributions of bands B-E to the region A-E were 61% in the control rat, only 27% after 21 days of castration and 35% when testosterone was given between days 14 and 21 of castration. The components of bands A-E are presumed to be proteins since the electrophoretic pattern was altered by digestion with pronase but not by ribonuclease, phospholipase C or neuraminidase. Epididymides from castrated and androgen-treated castrated rats were incubated with 14C- and 3H-labelled mixed amino acids respectively. After co-electrophoresis the ratio 3H: 14C rose from a baseline of 2-5 in band B, 32 in band C and 7 in bands D and E. Molecular weights were estimated as 27900 for B, 23100 for C and 34400 for D. Band A had the same electrophoretic mobility as serum albumin. Bands B and C were also present in testicular cytosol. Bands D and E were only found in the epididymis, localized mainly within the lumen of the tubules. Bands B-E increased with age during sexual maturation, bands D and E became detectable in the 20-day-old rats. Preliminary evidence indicates that the proteins in bands C, D and E can be removed from caput spermatozoa by washing.
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PMID:Androgen-controlled specific proteins in rat epididymis. 127 Sep 59

The present study was undertaken to determine whether small cell lung cancer (SCLC) cell lines produce immunosuppressive factors and, if they do, to characterize the factors. The supernatants of SCLC cell lines, H69 and N857, inhibited not only the blastogenic response of human peripheral blood lymphocytes (PBL) to phytohemagglutinin or concanavalin A, but also the cytotoxic activity of lymphokine-activated killer cells. Neither was inhibited by supernatants from non-SCLC cell lines PC9, QG56, and A549. The immunosuppressive activity of H69 supernatant was stable upon heating to 56 degrees C for 60 min, but labile when heated to 70 degrees C for 10 min. The activity was abolished after dialysis at pH 2.0 or pH 11.0, but not at pH 4.5 or pH 9.0. Digestion with trypsin or proteinase eliminated the immunosuppressive activity, whereas treatment with neuraminidase, mixed glycosidase, DNase or RNase had no effect, suggesting that the immunosuppressive activity in H69 supernatant is due to a protein factor. This H69-derived immunosuppressive factor was isolated by ion exchange chromatography using a gradient of 0.04 to 0.08 M NaCl solution. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed the factor to have molecular weights of 98 kD and 102 kD, respectively. These results suggest that SCLC cells produce a potent immunosuppressive factor which may account for the immune deficiency in SCLC patients.
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PMID:Characterization and purification of an immunosuppressive factor produced by a small cell lung cancer cell line. 185 Jul 26

This investigation sought to characterize biochemically the tumor-specific transplantation antigens (TSTA) expressed on the cell surface of a panel of chemically induced fibrosarcomas of C3H/HeJ mice. Results suggest a uniform antigenic framework upon which individual specificities are superimposed. The antigens expressed by the 3-methylcholanthrene-induced fibrosarcomas MCA-D, MCA-F, and MCA-2A fulfill the requirements of a TSTA; namely, immunization of syngeneic hosts with irradiated cells or soluble extracts engenders a tumor-specific immune response such that animals resist challenge with the same, but not another, tumor. Brief incubation of intact tumor cells in single-phase aqueous solutions of 2.5% (v/v) 1-butanol extracts an immunoprotective TSTA, but not alloantigenic activity, from MCA-F cells. This extraction protocol was extended to the two other MCA-induced neoplasms. The butanol-extracted TSTA from the three tumors displayed isoelectric pHs of 6.4 to 6.6 following preparative isoelectric focusing. The tumor-specific immunoprotective activity from all three tumors displayed an apparent molecular weight of 150,000 (150 kDa) during high-performance gel permeation chromatography. The chromatographic properties of the 150 kDa antigens were unaffected by reduction using dithiothreitol, but incubation in acetate buffer, pH 3.0, dissociated the 150 kDa complex into at least two components with molecular weights of 70 to 100 kDa and 20 to 40 kDa. Only the smaller component displayed TSTA activity. The presence of two major components in the 150-kDa antigen was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. TSTA activity was sensitive to digestion with pronase, papain, chymotrypsin, and alpha-mannosidase, but resistant to DNase, RNase, neuraminidase, trypsin, endoglycosidase H, and a mixed-function glycosidase. In addition, the TSTA activity was unaffected by heating. These data demonstrate that MCA carcinogenesis results in the expression of immunologically unique epitopes on biochemically related glycoproteins and suggest a unified mechanism for the generation of TSTA polymorphism.
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PMID:Biochemical characterization of 1-butanol-extracted murine tumor-specific transplantation antigens. 240 45


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