Pyrrylmethane intermediates in the synthesis of uroporphirigonen III by soybean callus porphobilinogenase

Abstract

1. 1. Further evidence for the formation of pyrrolic intermediates resulting from action of soybean callus porphobilinogenase on porphobilinogen in the absence or presence of ammonia, under anaerobic conditions, is reported. 2. 2. It was found that the activity of porphobilinogenase was affected by the presence of air; the yield of uroporphyrinogens was very low, although consumption of substrate was not greatly modified. These results suggested that some intermediate in the reaction was still being formed, but that this compound must be in the reduced form to be further converted into uroporphyrinogens. It was observed that ammonia probably produced as accumulation of pyrryl intermediates, but that they synthesize uroporphyrinogen III at a slower rate. 3. 3. Attempts were made to detect the formation of an enzyme-substrate complex, but they all failed.