Inhibition of creatine kinase by iodoalkanes. Further appraisal of the essential nature of the reactive thiol group.

Creating kinase (ATP: creatine N-phosphotransferase) is completely inhibited by low molecular weight iodoalkanes in a pseudo first order reaction. Analysis of this and other data suggests that covalent modification per se is not a sufficient criterion to establish whether or not an enzyme group is essential for catalysis.