OBJECTIVES: 1) The pH variation of the dissociation constants of N-oxalyl- and N-glycolylethanolamine from glutamate dehydrogenase will be determined in order to deduce a chemical mechanism. 2) The pH variation of isotope exchange and isotope partition experiments with yeast hexokinase will be used to determine a kinetic mechanism. 3) The isomers of GATP will be separated, characterized, and used to determine enzyme specificity.