1. No. 2 in a series. No. 1 appeared in J. Biol. Chem., 237, 2926 (1962).
2. A preliminary account of this work was presented before the American Society of Biological Chemists in Atlantic City, New Jersey, April 1962.
3. Weurman, C., and Swain, T., Nature, 172, 678 (1953).
4. Siegelman, H. W., Arch. Biochem. Biophys., 56, 97 (1955).
5. Griffiths, L. A., Nature, 184, 58 (1959).