Serine transhydroxymethylase was purified one thousand-fold from bovine brain and one hundred and twenty-fold from bovine liver. Both enzymes were yellow due to the presence of the coenzyme pyridoxal 5'-phosphate. Polyacrylamide gel electrophoresis of the liver enzyme showed one major band containing 95% of the protein, while in the case of the brain enzyme two major bands of nearly equal intensity were observable. The specific activity of the crude liver enzyme was about sixty times higher than that of brain. The liver enzyme was also more heat stable than the brain enzyme. The purified enzymes exhibited L-allothreonine and L-threonine aldolase activities besides serine transhydroxymethylase activity. Electro focusing established the isoelectric point of liver enzyme at 8.75 and a value of 8.90 was obtained from the brain enzyme. The molecular weight of the brain enzyme was found to be 229,000 ± 20,000 while the liver enzyme had a value of 245,000 ± 20,000. pH optima of the enzymes were around 8.0. A similarity in antigenic properties was established for the enzymes from both tissues.
College and Department
Chemistry and Biochemistry
BYU ScholarsArchive Citation
Panichajakul, Sanha, "A comparative investigation of mammalian serine transhydroxymethylases" (1975). Theses and Dissertations. 8326.