Transphosphorylation, 2ADP⇄AMP+ATP, occurred in the presence of intact Escherichia coli (E. coli. strain K-12) in neutral phosphate buffer solution, because adenylate kinase existed in both cytoplasma and periplasma of E. coli. Cyclodextrin(CD)s accelerated the transphosphorylation. The reaction rate depended on the concentration of CD and the kind of CD. Methylated CDs were more effective than parent CD, especially, hiptakis-(2,6-di-O-methyl)-β-CD(DMCD) was most effective. Addition of CDs makes neither change of E. coli concentration nor the leak of adenylate kinase from periplasma of E. coli
