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. 1974 May;71(5):1701–1704. doi: 10.1073/pnas.71.5.1701

Characterization and Substrate Specificity of a Protein Carboxymethylase in the Pituitary Gland

Emanuel J Diliberto Jr *, Julius Axelrod 1
PMCID: PMC388306  PMID: 4365760

Abstract

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 Km of 1.47 μM 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.

Keywords: protein hormones, S-adenosyl-L-methionine, neuroendocrine, methanol-forming enzyme

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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