Tyrosine Decarboxylase

Abstract

The principle of opt. nutrition for max. function, previously applied to the production of cells with a very active tyrosine decarboxylase system, has been used to obtain cells with a large amt. of tyrosine decarboxylase apoenzyme. The production of the apoenzyme by growth under controlled conditions offers a promising method for the study of enzyme systems without the tedious process of resolving the enzyme after its separation from tissue. The production of an apoenzyme by growth in the absence of the vitamin contained in the coenzyme constitutes evidence against the universal occurrence of B vitamin in all cells. The vitamin B6-deficient cells of Streptococcus faecalis R may be used for the assay of codecarboxylase (pyridoxal phosphate) or of pyridoxal.