Alpha-tocopheryl acetate hydrolase in chicken liver. Characterisation and properties.

An enzyme catalysing the hydrolysis of a-tocopheryl acetate was characterised in chicken liver. The enzyme was localised in the microsomes, had an optimum pH 8·6 and a Km value of 0·5 mM. The enzyme did not hydrolyse retinyl acetate, cholesteryl acetate and ethyl acetate, thus indicating a high degree of specificity. a-Tocopheryl acetate hydrolase required bile salts as a specific cofactor. The results suggested a role for this enzyme in the absorption of vitamin E.