Formation of Cys-heme cross-link in K42C myoglobin under reductive conditions with molecular oxygen

Sperm whale myoglobin (Mb) mutant, K42C Mb, with a Cys introduced at position 42 close to the heme 4-vinyl group, partially forms a Cys-heme cross-link dithiothreitol (DTT)-induced reductive conditions in presence of O2, as indicated by mass spectrometry (MS) and other experimental results.240