The catalytic activity of human myoglobin is enhanced by a single active site mutation: F43Y

Abstract
Phenylalanine-43 in the haem pocket of human myoglobin has been replaced by tyrosine using site-directed mutagenesis: the tyrosine-43 mutant is approximately 25 times more active than the wild-type protein in mediating the oxidation of styrene by hydrogen peroxide, and gives a 96:4 ratio of R/S styrene oxide (60% of products) in contrast to the racemate (46% of products) produced by the wild-type.