Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A study was made of the effect of the low-molecular neuropeptides, leu- and met-enkephalins, thyroliberin (TRH), the C-end tripeptides, gastrin (MAF) and oxytocin (MIF) on the content of biogenic monoamines and their metabolites and on the production of humoral antibodies to sheep red blood cells. The action of the peptides enumerated was compared to that of the peptide immunostimulant, tuftsin. All the peptides (upon intraventricular administration) with the exception of tuftsin affect the content of brain biogenic monoamines or their metabolites. Moreover, upon intravenous injection the neuropeptides under study except met-enkephalin exert a modulating action on the immune response pattern and intensity Leu-enkephalin, MIF and MAF have immunostimulant activity similar to tuftsin. TRH given in high doses (100 and 150 mg/kg) provokes almost a two-fold decrease in the antibody titer. This peptide has an immunosuppressant effect when administered both intravenously and intracisternally. It is suggested that neuro- and immunomodulator effects have much in common at the level of cell receptors.
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PMID:[Comparison of the neuro- and immunomodulator properties of low-molecular neuropeptides]. 612 28

A post-proline cleaving enzyme [prolyl endopeptidase, EC 3.4.21.26] was purified about 3,700-fold from an extract of bovine brain by a series of column chromatographies on DEAE-Sephadex, hydroxyapatite and PCMB-T-Sepharose, and gel filtration on Sephadex G-200 using N-carbobenzoxy-Gly-Pro-beta-naphthylamide (Z-Gly-Pro-2-NNap), thyrotropin releasing hormone (TRH) and oxytocin as substrates. The purified enzyme appeared homogeneous as judged by disc gel and SDS gel electrophoreses. The enzyme was most active at pH 7.5 and 7.2 with Z-Gly-Pro-2-NNap and TRH, respectively, and hydrolyzed peptide bonds involving Pro-X (X=amino acid, peptide, ester and amide) bonds of synthetic substrates, oxytocin, vasopressin, neurotensin, substance P, tuftsin, bradykinin, and insulin B chain. However, the enzyme was inert toward collagen, gelatin, and casein. The enzyme was completely inactivated by diisopropylphosphorofluoridate (DFP), Z-Gly-Pro-chloromethyl ketone and p-chloromercuribenzoate (PCMB), while it was not inhibited by phenylmethane sulfonylfluoride (PMSF) or metal chelators. Determination of the amino acid composition revealed that the enzyme contained 25 half-cystines. Modification of three cysteine residues of the enzyme by PCMB led to complete inactivation. The isoelectric point of the enzyme was 4.8, and the molecular weight was estimated to be 76,000 by ultracentrifugal analysis and 75,000-74,000 by both gel filtration and sodium dodecyl sulfate (SDS) gel electrophoresis, suggesting that the enzyme is present as a monomer. These results indicate that the post-proline cleaving enzyme from bovine brain is very similar to those previously purified from lamb brain and kidney in its enzymatic properties, substrate specificity and physicochemical properties, in sharp contrast with the results obtained by Tate, who reported that the bovine brain prolyl endopeptidase was inert toward oxytocin, vasopressin and bradykinin.
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PMID:Post-proline cleaving enzyme (prolyl endopeptidase) from bovine brain. 636 Oct 10

A bovine brain thyrotropin-releasing-factor (thyroliberin) deamidase has been purified 1100-fold to apparent homogeneity. Molecular weight estimates by gel filtration and sodium dodecylsulfate gel electrophoresis indicate that the enzyme consists of a single polypeptide chain of molecular weight of about 62 000-65 000. The enzyme is inactivated by sulfhydryl blocking agents. Serine proteinase inhibitors, phenylmethanesulfonyl fluoride and benzamidine, have no effect. Besides thyroliberin, the enzyme hydrolyzes peptide bonds involving the carboxyl group of proline residues in luliberin, tuftsin, angiotensin II, melanotropin, and neurotensin. Oxytocin, vasopressin, and bradykinin are not cleaved; they are, however, strong competitive inhibitors of thyroliberin deamidation. The specificity studies indicate that the enzyme is a "post-proline cleaving enzyme" which hydrolyzes peptides of the general structure, Yaa-Pro-Xaa, in which Xaa = amino acid, peptide, or amide (not Pro), and Yaa = N-blocked basic amino acid or a peptide sequence in which the C-terminal residue (i.e. the residue prior to Pro) is a basic amino acid such as His, Lys, or Arg. The enzyme is compared to other post-proline cleaving enzymes.
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PMID:Purification and properties of a bovine brain thyrotropin-releasing-factor deamidase. A post-proline cleaving enzyme of limited specificity. 679 65