Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.26.9 (ribonuclease)
6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Binding sites for prolactin were identified in a plasma-membrane-enriched fraction isolated from livers of mature female rats. 125I-labelled sheep prolactin prepared by the lactoperoxidase procedure retained the same molecular integrity and binding affinity as the native hormone at physiological pH. The receptors bound prolactin from different species, whereas non-lactogenic hormones were not bound. The binding of 125I-labelled sheep prolactin was activated equally by bivalent and univalent cations, bivalent cations exerting their maximal effect at much lower concentrations. The association of 125I-labelled sheep prolactin with the receptor was a time- and temperature-dependent process. Partial dissociation was detected. The binding of 125I-labelled sheep prolactin was strongly influenced by pH, with an optimum observed at pH 6.5. Receptor activity was destroyed by Pronase and phospholipase C, whereas neuraminidase increased binding. Treatment of the membranes by ribonuclease and deoxyribonuclease did not affect the binding. Binding of 125I-labelled sheep prolactin was inhibited by p-chloromercuribenzoic acid, dithiothreitol and by brief exposure to high temperatures. Scatchard analysis of the binding of 125I-labelled sheep prolactin to receptors indicated that prolactin has a high affinity for its receptor. Binding of prolactin to liver membranes showed some properties different from those observed with mammary cells. Binding by these tissues differed in pH optimum, in effects of ions, and in response to neuraminidase.
...
PMID:Characterization of prolactin binding by membrane preparations from rat liver. 3 84

An antigen was detected in pooled human nephroblastomas using antiserum prepared in rabbits against an ethylemediaminetetra acetic acid (EDTA) extract of the tumors. This antigen was not found in normal human plasma or kidney extracts, and was not related to the ABO or Forssman blood groups. The antigen was detected in extracts of cultured nephroblastoma cells, but was not present in extracts of normal human fetal kidney cell cultures. The antigen is believed to be present at the cell surface, as cell viability was not significantly lowered during the extraction procedure. A reaction of complete identity was demonstrated by Ouchterlony double diffusion experiments with this antigen and purified bovine fetuin. The antigen was not found in extracts of human fetal spleen, thymus or kidney, nor in human fetal serum. Furthermore, the antigen does not possess determinants in common with the human alpha-fetoprotein of hepatomas, nor was it detected in human renal clear cell carcinoma. Initial characterization of the antigen showed it to be nondialysable, not sedimentable at 100,000 times g for 2 h, stable to repeated freeze-thawing and to incubation at 56 degrees C for 1 h, and water soluble over a wide pH range. The antigen was susceptible to digestion with pronase and trypsin and possibly hyaluronidase, but not to ribonuclease or neuraminidase. The protein portion is therefore of major importance to the structural integrity of this antigen. The relationship between this antigen and other abnormal materials reported previously in nephroblastoma patients is being studied.
...
PMID:A fetuin-like antigen from human nephroblastoma. 5 Feb 93

By application of electron cytochemical techniques to cerebellar tissue, the presence of proteoglycans was demonstrated at the axoplasmic matrix of mossy fiber endings. Blocks of glutaraldehyde (G) fixed mouse cerebellum were processed according to the following procedures: a) Some pieces of tissue were post-fixed in osmium tetroxide, dehydrated by ethanol and embedded in araldite. b) Other pieces were sectioned to 30 mum thick and then immersed in Alcian blue solution pH = 2.7 followed by osmium tetroxide fixation, dehydrated and embedded in araldite (GABOUL procedure). c) Parallel slices of (b) previous to Alcian blue immersion were washed and incubated in either methanol-HCl, neuraminidase, ribonuclease or testicular hyaluronidase with their respective controls. d) Other blocks of G fixed tissue without any other treatment and fixation were dehydrated and embedded in araldite. Ultrathin sections of a, b and c were doubly stained with uranyl acetate and lead citrate while ultrathin sections of (d) were stained with the osmium coordination compound Os-DMEDA. The electron microscopic study revealed at the presynaptic axoplasm of mossy fiber rosettes, the presence of a GABOUL and Os-DMEDA positive electron dense material surrounding synaptic vesicles and continuous with presynaptic dense projections. This material which coincides with cytonet distribution was resistant to neuraminidase and ribonuclease and sensible to hyaluronidase and carboxymethylation. These findings permit us to conclude that the axoplasmic material of mossy fiber endings is constituted by proteoglycans in which hyaluronic acid and chondroitin 4-and/or 6-sulphate are present. The probable importance of these proteoglycans in synaptic mechanisms is also discussed.
...
PMID:Electron microscopic demonstration of hyaluronidase sensible proteoglycans at the presynaptic area in mouse cerebellar cortex. 6 92

Circulating M antigen, previously described in urine from patients infected by Schistosoma mansoni, was shown in serum from infected patients, using human anti-M immune serum with immunodiffusion and immunoelectrophoretic analyses. This antigen was also shown to be present in the serum and urine from infected hamsters, in the urine from infected rabbits and in the serum from infected mice. Generally, it appeared on day 20 after infection. M antigen was specific for the genus Schistosoma and for the immature and adult worm stage. Its electrophoretic migration was cathodic. The molecular weight of urinary M antigen was around 45,000 daltons. The M antigen was thermostable, soluble in trichloroacetic acid, and contained no lipid component. It was hydrolyzed by protease, ribonuclease, amylase or neuraminidase, but was destroyed by sodium metaperiodate. All these properties betoken the polysaccharidic nature of M antigen.
...
PMID:Further studies on the circulating M antigen in human and experimental Schistosoma mansoni infections. 10 64

Mouse 3T3, Simian virus 40 transformed 3T3 cells (SV3T3) and two SV3T3 lines showing reversion of their transformed phenotype (Rev 3 and Rev 5) have been studied with respect to electrophoretic mobilities and colloidal iron hydroxide (CIH) binding density visible by electron microscopy, before and after incubation with neuraminidase or ribonuclease. The results show that, in general, the marked changes in both sets of surface parameters associated with transformation are largely reversed in the Rev 5 revertant, and only partially reversed in the Rev 3 line. It was also observed that, in common with Ehrlich ascites tumor (EAT) cells examined previously, the densities of CIH-particles bound over the microvilli of all the cell types was 1.5 to 2.7 times higher than those bound to the spaces between them. In contrast to the EAT cells, the higher density of CIH particles bound over the microvilli was not due to neuraminidase-sensitive binding sites.
...
PMID:Some electrical properties of the peripheries of murine 3T3 cells with respect to viral transformation and reversion. 17 59

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.
...
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.
...
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

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.
...
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 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.
...
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.
...
PMID:[Specific resistance and electrophoretic mobility of regenerating liver cells. Effect of ribonuclease and neuraminidase]. 125 13


1 2 3 4 Next >>

---