Effects of alpha-ketoglutarate on the activities of the glutamate synthase, glutamate dehydrogenase, and aspartate transaminase of sweet potato, yam tuber, and cream pea
1991
Osuji, G.O. | Cuero, R.G. | Washington, A.C.
The regulation of ammonium ion salvage by alpha-ketoglutarate (alpha KG) in crops was investigated by photometric assays of the activities of glutamate synthase (GOGAT), glutamate dehydrogenase (GDH), and aspartate transaminase (GOT), isolated from yam and sweet potato tubers (protein-deficient crops) and cream pea (protein-rich crop). Whereas the cream pea GDH and GOGAT were not inhibited by alpha KG, the yam tuber GDH was competitively inhibited (Ki of 1.3 mM) and the sweet potato GOGAT was noncompetitively inhibited (Ki of 1.0 mM) by alpha KG. The Km values of GDH and GOGAT for alpha KG were higher in the yam and sweet potato than in the cream pea. The GOTs were not inhibited by alpha KG. By inhibiting the GDH of yam tuber and the GOGAT of sweet potato, alpha KG may be reducing the efficiencies of the crops in ammonium ion salvage and in protein storage.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by National Agricultural Library