Stoichiometry of oxygen consumption in the biosynthesis of isopenicillin from a tripeptide

The biosynthesis of isopenicillin N from delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine in a cell-free system has been correlated wih O2 consumption by two methods, involving the use of an oxygen-electrode and an n.m.r. spectrometer respectively. The results are consistent with a 1 : 1 stoichiometric ratio for the dioxygen consumed to the isopenicillin N formed.