The Effect of Amino Acid Analogues on Alkaline Phosphatase Formation in Escherichia coli K-12

In a histidine auxotroph of Escherichia coli, the replacement of histidine by 2-methylhistidine during protein synthesis completely prevented the formation of active alkaline phosphatase. Instead, inactive subunits of the enzyme that were detected with antisubunit antibody accumulated. These subunits exhibited two interesting properties not previously observed: (a) an anomalous behavior on Sephadex G-100 and (b) a precipitin line with antienzyme antibody that showed a cross-reaction of partial identity with native enzyme. Subunits obtained from a mutationally altered form of alkaline phosphatase also possessed these characteristics, and studies with this protein are also included here.