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)

Protein carboxymethylase, an enzyme capable of methylating proteins and polypeptides, was purified from bovine pituitary. The anterior pituitary hormones, luteinizing hormone, follicle-stimulating hormone, adrenocorticotropic hormone, growth hormone, thyroid-stimulating hormone, and prolactin, were found to be substrates for this enzyme. The posterior pituitary hormones, oxytocin and vasopressin, did not serve as substrates. With luteinizing hormone as the substrate, protein carboxymethylase had a pH optimum near pH 5.5. A limiting K(m) of 1.47 muM for S-adenosyl-L-methionine was obtained with luteinizing hormone as the methyl acceptor. Possible roles of this enzyme in the posterior and anterior pituitary are discussed.
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PMID:Characterization and substrate specificity of a protein carboxymethylase in the pituitary gland. 436 60

The activity of protein carboxymethylase and the endogenous protein methyl acceptor capacity were examined in the posterior, intermediate, and anterior lobes of the pituitaries of homozygous Brattleboro rats with diabetes insipidus and in heterozygous Brattleboro and Long-Evans control rats. Protein carboxyl methylation is selectively altered in the posterior pituitary lobes of homozygous Brattleboro rats. Protein carboxymethylase activity is higher (+40%) and endogenous methyl acceptor protein capacity is lower (-80%) with respect to heterozygous Brattleboro and Long-Evans control rats. This latter change is correlated with decreased methylation of proteins of a molecular weight of approximately 11K daltons, is selective for the posterior pituitary lobe, since it does not occur in the intermediate and anterior lobes, and probably reflects the absence of vasopressin-associated neurophysin in homozygous Brattleboro rats. Our results support a physiological role of protein carboxyl methylation in the neurosecretory process in the posterior pituitary gland.
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PMID:High-protein carboxymethylase activity and low endogenous methyl acceptor proteins in posterior pituitary lobe of rats lacking neurophysin-vasopressin (Brattleboro rats). 686 19

The methyl-acceptor activities of bovine neurophysins I and II for the enzyme protein carboxymethylase (EC 2.1.1.24) were found to be similar and as high as for other previously identified, biologically active protein substrates. Effects on the rate of methylation of these neurophysins were investigated with the posterior pituitary hormone ligands, oxytocin and vasopressin, and the hormone-related tripeptide ligand, methionyl-tyrosyl-phenylalaninamide. An increase in the rate of neurophysin II methylation was observed with both oxytocin and tripeptide. This ligand-induced response did not occur with either native neurophysin I or disulfide-scrambled neurophysin II.
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PMID:The effects of ligands on enzymic carboxyl-methylation of neurophysins. 1562 82