A Novel Tyrosine-Heme CO Covalent Linkage in F43Y Myoglobin: A New Post-translational Modification of Heme Proteins

Heme post‐translational modification plays a key role in tuning the structure and function of heme proteins. We herein report a novel tyrosine–heme covalent CO bond in an artificially produced sperm whale myoglobin (Mb) mutant, F43Y Mb, which formed spontaneously in vivo between the Tyr43 hydroxy group and the heme 4‐vinyl group. This highlights the diverse chemistry of heme post‐translational modifications, and lays groundwork for further investigation of the structural and functional diversity of covalently‐bound heme proteins. Quality bonding time: A novel tyrosine–heme covalent CO bond in an artificially produced sperm whale myoglobin (Mb) mutant, F43Y Mb, formed spontaneously in vivo between the Tyr43 hydroxy group and the heme 4‐vinyl group. This highlights the diverse chemistry of heme post‐translational modifications, which play a key role in tuning the structure and function of heme proteins.