Identification of the cysteine residue responsible for oxidative inactivation of mouse galectin-2

In this study, we used point-mutated recombinant mGal-2 proteins to study which of the two highly conserved Cys residues in mGal-2 must be S-nitrosylated for protection against oxidative inactivation. Mutation of Cys57 to a Met residue (C57M) did not result in lectin inactivation following H2O2 treatment, whereas Cys75 mutation to Ser (C75S) led to significantly reduced lectin activity, as is the case for wild-type mGal-2. However, pre-treatment of the C75S mutant with S-nitrosocysteine protected the protein from H2O2-induced inactivation. Therefore, Cys57 is suggested to be responsible for oxidative inactivation of the mGal-2 protein, and protection of the sulfhydryl group of the Cys57 in mGal-2 by S-nitrosylation is likely important for maintaining mGal-2 protein function in an oxidative environment such as the gastrointestinal tract.

Source: Journal of Biochemistry - October 2, 2016 Category: Biochemistry Authors: Tamura, M., Sasai, A., Ozawa, R., Saito, M., Yamamoto, K., Takeuchi, T., Ohtake, K., Tateno, H., Hirabayashi, J., Kobayashi, J., Arata, Y. Tags: Regular Papers Source Type: research