title: Antigenic similarities between ferredoxin-dependent nitrite reductase and glutamate synthase from Chlamydomonas reinhardtii.
abstract: Polyclonal antisera were prepared against ferredoxin-nitrite reductase (EC 1.7.7.1) and ferredoxin-glutamate synthase (glutamate synthase (ferredoxin); EC 1.4.7.1) from the green alga Chlamydomonas reinhardtii. The anti-glutamate synthase antibodies recognized both glutamate synthase and nitrite reductase, but inhibited only the ferredoxin-linked activity of the latter enzyme and not the activity dependent on methyl viologen. Analogously, the anti-nitrite reductase antibodies recognized glutamate synthase and nitrite reductase but the first enzyme was only poorly inhibited. Free ferredoxin protected the nitrite reductase against its inactivation by anti-glutamate synthase antibodies. These results indicate that the ferredoxin-dependent glutamate synthase and nitrite reductase from this alga share common antigenic determinants, and that these are located at the ferredoxin-binding domains.
mesh_terms: D002696:Chlamydomonas / Q000201:enzymology* / Q000276:immunology; D003429:Cross Reactions; D050900:Ferredoxin-Nitrite Reductase; D005288:Ferredoxins / Q000494:pharmacology; D005970:Glutamate Synthase / Q000276:immunology*; D005779:Immunodiffusion; D009247:NADH, NADPH Oxidoreductases / Q000276:immunology*; D009572:Nitrite Reductases / Q000276:immunology*; D000637:Transaminases / Q000276:immunology*
chemical_list: D005288:Ferredoxins; D005970:Glutamate Synthase; D009247:NADH, NADPH Oxidoreductases; D009572:Nitrite Reductases; D050900:Ferredoxin-Nitrite Reductase; D000637:Transaminases