Pyrroline-5-carboxylate reductase of Neurospora crassa; partial purification and some properties.

Previous studies (1, 2) with mutant and wild type strains of Neurospora crassa have pointed to glutamic y-semialdehyde and its spontaneously cyclized form, Al-pyrroline-5-carboxylate, as intermediates in the biosynthesis of proline. These studies, based largely on experiments in vivo, have recently been substantiated through work in vitro with extracted enzymes (3, 4). ‘The terminal step in proline formation, namely the reduction of PC,’ was shown (3) to be catalyzed by pyrroline-5-carboxylate rednctase according to the following schematic equation: