Localization of oxalacetate keto–enol-tautomerase

Abstract

The intracellular location of oxalacetate keto-enol-tautomerase (oxaloacetate keto-enolisomerase) (EC 5.3.2.2) has been determined in two types of animal cells, rat liver and pig kidney. Two fractionation procedures were adopted and modified to suit each type of tissue. One fractionation procedure gave the soluble phase, microsomal and mitochondrial fractions, while the other isolated the nuclear fraction. The tautomerase is distributed among the soluble phase, microsomes and mitochondria in both tissues. Fractionation efficiency was checked by determining percentage recoveries of enzymic activity and total protein after each step, by microscopy studies and by determining the distribution of several marker enzymes.

Escherichia coli fumarase A catalyzes the isomerization of enol and keto oxalacetic acid

“…It has been known for some time that an enzymatic activity exists in several organisms which catalyzes the conversion of enol to keto oxalacetic acid (herein referred to as OAA) (Annett & Kosicki, 1969;Wesenberg et al, 1976). The Nomenclature Committee of the International Union of Biochemistry has given this activity the name OAA ketoenol-isomerase (herein referred to as OAAKE isomerase) and the numerical designation EC 5.3.2.2.…”