This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Mazelis, M. Articles by Liu, E. S. Search for Related Content PubMed PubMed Citation Articles by Mazelis, M. Articles by Liu, E. S. Agricola Articles by Mazelis, M. Articles by Liu, E. S.

Articles

Serine Transhydroxymethylase of Cauliflower (Brassica oleracea var. botrytis L.): Partial Purification and Properties ¹

Department of Food Science and Technology, University of California, Davis, California 95616

Serine transhydroxymethylase (EC 2.1.2.1) has been purified 46-fold from cauliflower (Brassica oleracea var. botrytis L.). The enzyme was completely dependent on the presence of tetrahydrofolic acid for the conversion of serine to glycine. The addition of pyridoxal phosphate gave a large increase in the reaction rate. A double pH optimum was observed with maxima at 7.5 and 9.5. The enzyme is specific for L-serine. The D-isomer is neither a substrate nor an inhibitor. The Michaelis constants for L-serine, tetrahydrofolic acid, and pyridoxal phosphate were 300 µM, 760 µM, and 24 µM, respectively. The addition of K⁺ also stimulated the reaction rate considerably. The effect was quite specific since all other metal ions tested either had very little: influence or were extremely inhibitory.