Isozymes of Glutamate Dehydrogenase in Chlamydomonas reinhardi*, †

SYNOPSIS. Two electrophoretically distinct forms of glutamate dehydrogenase were found in extracts of Chlamydomonas reinhardi. The slower moving of these was detectable only when the cells were grown organotrophically. The other, more active, enzyme copurified with chloroplasts and was not electrophoretically detectable in extracts of organotrophically grown cultures of the y-2 mutant strain; this absence was not apparent in wild type or in the mutant strain y-1. Both forms of the enzyme were cofactor non-specific.