ARGININE METABOLISM IN CHLAMYDOMONAS REINHARDI - EVIDENCE FOR A SPECIFIC REGULATORY MECHANISM OF BIOSYNTHESIS

The arginine‐requiring mutant of Chlamydomonas reinhardi, isolated by Ebersold in 1956 and called arg‐1, shows no activity of the enzyme acetyl‐glutamate‐reductase, for this reason we propose to call this mutant arg C1. By analogy with this we call the arginine‐requiring mutant arg‐2, isolated by Eversole in 1956, arg G2. Under circumstances in which the synthesis of the last enzyme of the arginine pathway, the argininosuccinate lyase, shows strong repression and derepression, we could not find any regulation of the synthesis of the 2nd up to and including the 6th enzyme of this pathway. A more detailed study on the 6th enzyme of the pathway, the ornithine transcarbamylase, also failed to show any regulation of the synthesis. The findings of 2 and 3 support our hypothesis on the regulation of the arginine biosynthesis in Chl. reinhardi, which we presented in the preceding paper. Copyright © 1969, Wiley Blackwell. All rights reserved