Sheep tissue acetyl coenzyme A-dependent arylamine N-acetyltransferases


Guray T. , Guvenc T.

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY, vol.118, no.3, pp.305-310, 1997 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 118 Issue: 3
  • Publication Date: 1997
  • Doi Number: 10.1016/s0742-8413(97)00175-8
  • Title of Journal : COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-PHARMACOLOGY TOXICOLOGY & ENDOCRINOLOGY
  • Page Numbers: pp.305-310

Abstract

Acetyl coenzyme A-dependent arylamine N-acetyltransferases (NATs), EC 2.3.1.5. were measured in sheep tissues (N = 14) using p-aminobenzoic acid (PABA) as a substrate. Specific activities of liver, kidney, and lung NATs were 5.3 X 10(-3) +/- 1.4 (mean +/- SE) nmoles.min(-1).mg protein(-1), 3.4 X 10(-3) +/- 1.1 nmoles.min(-1).mg protein(-1), 2.5 X 10(-3) +/- 1.2 nmoles.min(-1).mg protein(-1), respectively. K-m values were 53 +/- 3 mu M for liver, 34 +/- 2 mu M for kidney, and 28 +/- 2 mu M for lung tissue. Optimum pH for the acetylation reaction was found as 7.5. The enzyme activity was stable for at least 6 months in all tissues, when stored at -70 degrees C. The enzyme from sheep tissues were quite heat stable. Inhibition studies showed that N-ethylmaleimide was a potent inhibitor of sheep tissue NAT enzymes. (C) 1997 Elsevier Science Inc.