Physico-chemical properties of actin cleaved with bacterial protease from E. coli A2 strain.

The 36 kDa fragment of actin molecule obtained with the protease from E. coli A2 strain [(1988) FEBS Lett. 228, 172] was shown to begin with Val-43 and retain the COOH-terminal amino acid residues of the parent molecule. The E. coli protease split actin preserves the NH2-terminal part of the polypeptide chain as well as the native conformation of actin molecule. However, the E. coli protease split actin failed to polymerize in 0.1 M KCl, suggesting that integrity of actin molecule between Gly-42 and Val-43 is crucial for actin polymerization.