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Rat pituitary N alpha-acetyltransferase.

J E Dixon·T A Woodford
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Abstract

The rat pituitary contains an enzyme which will acetylate certain ACTH fragments using acetyl coenzyme A. This acetyltransferase activity was found in all three lobes of the rat pituitary as well as in all other tissues examined. The rat pituitary enzyme appears to be largely particulate in nature. The enzyme sedimenting at 27,000 and 100,000 g had specific activities 4-10 times greater than the soluble fraction. The acetyltransferase activity was dependent on substrate concentration (ACTH) and pH, was linear with time, and was inactivated at 55 degrees. The enzyme would acetylate ACTH(1-24), (1-10), and ACTH(4-10), but would not use ACTH(2-10), (3-10), or ACTH(1-8) as substrates. The apparent Km values for the substrates were as follows: AcCoA, 2.2 microM, ACTH(1-24), 4.2 microM; ACTH(1-10), 96 microM; and ACTH(4-10), 37 microM.

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AcetylationAcetyltransferasesAdrenocorticotropic HormoneAnimalsKineticsN-Terminal AcetyltransferasesPituitary GlandPituitary Gland, AnteriorPituitary Gland, PosteriorProtein Processing, Post-TranslationalRatsSubcellular FractionsSubstrate SpecificityTissue DistributionTritiumJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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J E Dixon, T A Woodford. 1984. Rat pituitary N alpha-acetyltransferase.. https://doi.org/10.1016/0076-6879(84)06017-1

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