[Membrane-bound precursor of E. coli periplasmic alkaline phosphatase: isolation and some properties]

Solubilization of membrane-bound alkaline phosphatase with 0.2% tritone X-100 and its purification to the homogenous state were performed. It was shown that the membrane-bound enzyme differed from the soluble enzyme by the N-terminal sequence, was more hydrophobic and was presented by one form of enzyme as compared to the three forms of the soluble one. By its substrate specificity this enzymes approximates the first form of the periplasmic enzyme, and does not differ from it by pH optimum, thermostability and the rate of inhibition by orthophosphate.