N.m.r. spectroscopy as a probe for the study of enzyme-catalysed reactions. Further observations of preuroporphyrinogen, a substrate for uroporphyrinogen III cosynthetase

Abstract

On the basis of n.m.r. and biochemical evidence, the hydroxymethylbilane structure (3) has been deduced for preuroporphyrinogen, the natural substrate for uro'gen III cosynthetase at pH 7·8–8·5 and 37 °C at 0 °C formation of another species, viz the N-alkylpyrrole (2), is indicated, thus reconciling previously conflicting interpretation of these data.