[1] UNIV PENN,DEPT BIOCHEM & BIOPHYS,PHILADELPHIA,PA 19104
[2] UNIV DUSSELDORF,INST BIOCHEM,W-4000 DUSSELDORF 1,GERMANY
[3] N DAKOTA STATE UNIV,DEPT BIOCHEM,FARGO,ND 58105
[4] TOKYO INST TECHNOL,DEPT LIFE SCI,YOKOHAMA,KANAGAWA 227,JAPAN
[5] UNIV ILLINOIS,DEPT CHEM,URBANA,IL 61801