Figure 5From: Recombinant sterol esterase from Ophiostoma piceae: an improved biocatalyst expressed in Pichia pastorisDetermination of oxidized methionine residues by amino acid analysis. Chromatograms obtained from a hydrolyzed standard sample in which methionine sulfone was added (‐‐‐‐‐), and from a hydrolyzed sample of recombinant protein (____). Structures of methionine and methionine sulfone are showed in the inner box.Back to article page