title: A radioisotopic assay for delta 1-pyrroline-5-carboxylate synthase activity.
abstract: A radioisotopic assay is described for measuring the activity of delta 1-pyrroline-5-carboxylate synthase, the enzyme that catalyzes the formation of delta 1-pyrroline-5-carboxylic acid from glutamic acid. Pyrroline-5-carboxylic acid is a common intermediate in the pathways through which glutamic acid, proline, and ornithine are interconverted. To determine pyrroline-5-carboxylate synthase activity, cell homogenates are incubated with [14C]-glutamic acid, the products of the reaction are converted quantitatively to proline by sodium borohydride, and proline is isolated by cation-exchange column chromatography. Cofactor requirements have been defined, and the activity of pyrroline-5-carboxylate synthase in several different cultured fibroblast lines is reported.
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D002460:Cell Line; D006224:Cricetinae; D005971:Glutamates; D018698:Glutamic Acid; D009953:Ornithine-Oxo-Acid Transaminase / Q000032:analysis*; D011392:Proline; D011758:Pyrroles; D000637:Transaminases / Q000032:analysis*
chemical_list: D002250:Carbon Radioisotopes; D005971:Glutamates; D011758:Pyrroles; C015485:delta-1-pyrroline-5-carboxylate; D018698:Glutamic Acid; D011392:Proline; D000637:Transaminases; D009953:Ornithine-Oxo-Acid Transaminase