The Activities of Glutamate Dehydrogenases during Mycelial Growth and Sporophore Development in Coprinus lagopus (sensu Lewis)

Abstract

SUMMARY: The activity of the NADP-linked glutamate dehydrogenase (GDHNADP) increased in the pileus during sporophore development but remained at a low level in the parent mycelium and in the sporophore stipe. In contrast, the NAD-linked enzyme (GDHNAD) increased in mycelium, stipe and pileus. It is suggested that the increase in GDHNADP activity is a developmental phenomenon. In vegetative mycelia the two GDH enzymes appeared to be regulated reciprocally; GDHNAD was subject to catabolite repression and urea derepression, while GDHNADP was catabolite derepressed and repressed by urea. It is suggested that GDHNAD may be the enzyme normally involved in ammonia assimilation, GDHNADP being reserved for specific functions associated with developmental alterations in metabolism.