Coenzyme-A-dependent Esterification of Cholesterol in Rat Intestinal Mucosa

Abstract

Haugen, R. & Norum, K. R. Coenzyme-A-dependent esterification of cholesterol in rat intestinal mucosa. Scand. J. Gastroent. 1976, 11, 615-621

Rat intestinal mucosa contains an enzyme which catalyses the esterification of cholesterol. The enzyme is CoA-dependent and probably an acyl-CoA: cholesterol acyltransferase (ACAT) (E.C.2.3.1.26). Maximal activity in vitro is obtained when long chain acylcarnitines, CoA and carnitine palmityltrans-ferase are used as an acyl-CoA generating system. The enzyme is localized in the microsomal fraction, has a pH optimum between 6.4-7.2, and oleate is the preferred acyl group. The activity of the enzyme is highest in the proximal jejunum, and has a capacity that can account for all cholesteryl esters found in intestinal rat lymph.

Key-words::

• Acylcarnitine
• acyl-CoA:cholesterol acyltransferase (ACAT)
• carnitine
• carnitine palmityltransferase
• coenzyme A (CoA)
• cholesterol
• cholesterol absorption
• cholesterol esterification
• cholesteryl esters
• microsomes
• mucosal cells