ABSTRACT
In 1971, Earl W. Sutherland, Professor of Physiology at Vanderbilt University, Nashville, was very justly awarded the Nobel Prize for Medicine or Physiology for his work on the second messenger. The elucidation of the structure of cholera toxin began in 1969 with Finkelstein's purification of cholera toxin and his demonstration and purification of the closely related inert protein choleragenoid, and with his further demonstration that choleragenoid was a derivative of the toxin rather than a precursor of it, or an independently synthesized protein. Research into the detailed mechanism by which cholera toxin activates adenylate cyclase was hampered for some years by the fact that the bipartite toxin needed time to work its way, or the active component's way, through the barrier of the cell membrane; and then, as long as the cell was intact, it was difficult to find out what was happening inside it.
