Gpt also known as Alanine aminotransferase 1, is a pyridoxal enzyme which catalyses the reversible interconversion of L-alanine and 2-oxoglutalate to pyruvate and L-glutamate. The Gpt is widely distributed in various tissues from animals and even in some kind of plants. It is suggested that c-ALT is associated to the utilization of pyruvate in glycolysis and m-ALT is involved in the conversion of alanine to pyruvate for gluconeogenesis. Recombinant rat Gpt, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques