Riordan J F
Med Clin North Am. 1976 Jul;60(4):661-74. doi: 10.1016/s0025-7125(16)31851-x.
The biochemistry of zinc has come under intensive investigation at the molecular level during the past 20 years. More than 70 zinc metalloenzymes are now known, and they span a broad range of biologic activities. Substitution of zinc by cobalt, for example, serves to locate a paramagnetic probe at the active site of the enzyme which can then provide information regarding the coordination properties of the metal and the active site environment.