Nitration of Tyrosine and Tyrosyl Residues in Myoglobin by the Action of Visible Light in the Presence of Riboflavin and Nitrite

Stepuro, I. I., et al. “Nitration of Tyrosine and Tyrosyl Residues in Myoglobin by the Action of Visible Light in the Presence of Riboflavin and Nitrite.” Journal of Applied Spectroscopy (2023): 1-11. https://doi.org/10.1007/s10812-023-01565-z

Abstract

The nitration of tyrosyl residues in proteins is considered a type of post-translational modification of proteins, indicating disruptions in the metabolic and signaling functions of nitric oxide NO and the development of oxidative nitrosative stress. We have examined the nonenzymatic pathway of protein nitration by the action of visible light in the presence of riboflavin and nitrite. Mass spectrometry was used to show that riboflavin-photosensitized redox processes involving nitrite and tyrosine or tyrosyl residues lead to nitration of residues Tyr-103 and Tyr-146 in the polypeptide chain of horse heart myoglobin. A possible role is discussed for riboflavin and other natural photosensitizers in the modification and damage of proteins when the body is exposed to intense visible light in the presence of nitrites in the blood.