Fractionation and properties of glutamic oxalacetic transaminase.

Because of the general nature of the transamination reaction (1, 2), a study of the kinetics and mechanism of reaction seemed of interest. Preliminary studies of this nature have already appeared (3-5). However, these studies were carried out with crude extracts or resolved enzyme systems. In order to conduct a critical kinetic study as well as a study of the mechanism of reaction, large amounts of a highly purified unresolved transaminase were required. Several fractionation schemes for the purification of the glutamic-oxalacetic transaminase have already appeared (6-8), but all of these methods utilized ammonium sulfate in the fractionation procedure and yielded a partially or completely resolved product in low yield. The low temperature alcohol fractionation (9, lo), so successful in plasma protein fractionation, appeared to offer some advantages over the ammonium sulfate technique. The following describes the preparation of a highly purified, unresolved glutamic-oxalacetic transaminase and presents some properties of the enzyme.