Arginine catabolism in Neurospora: cycling of ornithine
Year: 1977
Type: article
Abstract: We measured the metabolism of ornithine in Neurospora during the transition from minimal medium to arginine-supplemented medium. Within an hour after arginine supplementation, the amount of intracellular ornithine (95% of which had been stored in vesicles) dropped by 65%, even though the catabolism of arginine produces as much ornithine as had been produced on minimal medium. The arginine level in the cell rose 10-fold. Ornithine flux through the catabolic enzyme ornithine aminotransferase increased fivefold, but flux through the mitochondrial enzyme ornithine transcarbamylase (leading to arginine synthesis) was only 20% of the rate seen on minimal medium. During this transition to arginine catabolism, the enzymes of the arginine pathway operate as an ornithine cycle, but at a restricted rate. We suggest the hypothesis that high levels of arginine may inhibit the movement of ornithine into the vesicles and into the mitochondria.
Source: Journal of Bacteriology
Authors: B J Bowman, R H Davis
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W1627923176