The normal pathway for the biosynthesis of arginine was non-functional in polyoma infected-mouse cells. During viral replication, equimolar concentration of citrulline substituted for arginine but equimolar or ten times equimolar concentration of ornithine did not replace arginine. Purified polyoma virus obtained from infected cultures that were allowed to incorporate citrulline-14C revealed upon amino acid analysis that the label was found exclusively as arginine-14C. When the experiment was repeated using ornithine-14C the label was found as proline-14C and glutamate-14C and not arginine. Both normal and polyoma infected-mouse embryo cells possessed an active ornithine carbamoyltransferase. The inability of ornithine to serve as an arginine precursor appears to be due to the fact that exogenous ornithine is utilized by ornithine-δ-transaminase to synthesize proline and glutamate and not by ornithine carbamoyltransferase to synthesize citrulline.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Jun 9 1972|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology