@article{mbs:/content/journal/micro/10.1099/00221287-128-9-2203, author = "Rai, Amar N. and Rowell, Peter and Stewart, William D. P", title = "Glutamate Synthase Activity of Heterocysts and Vegetative Cells of the Cyanobacterium Anabaena variabilis Kütz", journal= "Microbiology", year = "1982", volume = "128", number = "9", pages = "2203-2205", doi = "https://doi.org/10.1099/00221287-128-9-2203", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-9-2203", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Glutamate synthase (GOGAT) activities in cell-free extracts of isolated heterocysts and whole filaments of the cyanobacterium Anabaena variabilis Kütz. (ATCC 29413) were determined by measuring [14C]glutamate production from 2-oxo[14C]glutarate or from [14C]glutamine, both of which are GOGAT substrates. There was negligible [14C]glutamate production from 2-oxo-[14C]glutarate in the presence of aminooxyacetate, which inhibits aminotransferase activity (<3% of that detectable in whole filament extracts). In experiments using [14C]glutamine, [14C]glutamate production by heterocyst extracts accounted for about 17% of that detected in whole filament extracts, even in the absence of 2-oxoglutarate, ferredoxin and sodium dithionite. It is concluded that virtually all the [14C]glutamate formed from [14C]glutamine in heterocyst extracts is independent of GOGAT activity.", }