Evidence for Synthesis of Alkaline Phosphatase on Membrane‐Bound Polysomes in Escherichia coli

Abstract

Polysomes containing nascent chains of alkaline phosphatase were isolated from a membrane-bound polysome preparation. Indirect immunoprecipitation using conformation-specific antibodies has been employed. This technique provides a good enrichment of these polyribosomes since routinely no more than 10-15% of non-specific immunoprecipitation was observed. The yield of the procedure is generally 40% but can be increased if higher non-specific immunoprecipitation is tolerated. Antibodies, previously described, directed against uncoiled or folded monomers of alkaline phosphatase can be used as primary antibody to recognize the nascent chains contained in membrane-bound polysomes which suggests that these chains are partially folded.