Induction of alkaline phosphatase in a subcellular preparation from Escherichia coli

Abstract

The ability of a subcellular fraction from the wild-type strain of E. coli (R1+R2+P+) to synthesize alkaline phosphatase was examined. A subcellular fraction (P1) prepared from penicillin-produced spheroplasts of E. coli after lysis with digitonin contains a high ratio of DNA to protein and consists mainly of membrane fragments. The P1 fraction contains about 10-15% of the original bacterial alkaline phosphatase; some of the enzyme is liberated from the bacteria during the preparation of the spheroplasts and some after lysis of the spheroplasts by digitonin. Conditions of incubation are described in which the P1 fraction synthesizes alkaline phosphatase. Actinomycin-D inhibits the synthesis of RNA and the induction of alkaline phosphatase in the P1 fraction. The inhibition can be partially overcome by the addition of a specific RNA from a constitutive mutant of the wild-type strain. Partial purification of the enzyme synthesized in-vitro indicates that there is enzyme synthesis during induction.