G C Ibeanu et al.
The Journal of biological chemistry, 271(21), 12496-12501 (1996-05-24)
Human P450 2C19 is selective for 4'-hydroxylation of S-mephenytoin and 5-hydroxylation of omeprazole, while the structurally homologous P450 2C9 has low activity toward these substrates. To identify the critical amino acids that determine the specificity of human amino acids that