Molecular weight analysis of the polypeptides of cholera phage PL 163/10 by polyacrylamide gel electrophoresis.

Cholera phage PL 163/10, belonging to Mukerjee's Group I, was purified by alternate cycles of low and high speed centrifugation. Gel electrophoresis revealed the presence of four polypeptide chains of respective molecular weights of 10,370+/-515 (A), 30,000+/-1,303 (B), 40,000+/-1,049(C) and 64,000+/-2,433 (D) daltons. Electrophoresis of the sample alkylated with iodoacetic acid resolved the presence of only one polypeptide chain of an average molecular weight of 10,310+/-565 daltons. The polypeptides B, C and D could be interpreted as trimer, tetramer and hexamer respectively of the polypeptide A, which was the basic structural protein of this phage.