Identification of the cysteine residue responsible for oxidative inactivation of mouse galectin-2.
Galectins are a group of animal lectins characterized by their specificity for β-galactosides. Mouse galectin-2 (mGal-2) is predominantly expressed in the gastrointestinal tract and has been identified as one of the main gastric mucosal proteins that are uniquely sensitive to S-nitrosylation. We have previously reported that oxidation of mGal-2 by hydrogen peroxide (H2O2) resulted in the loss of sugar-binding ability, whereas pre-treatment of mGal-2 with S-nitrosocysteine prevented H2O2-induced inactivation. 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 Cys57to a Met residue (C57M) did not result in lectin inactivation following H2O2treatment, whereas Cys75mutation 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, Cys57is suggested to be responsible for oxidative inactivation of the mGal-2 protein, and protection of the sulfhydryl group of the Cys57in mGal-2 by S-nitrosylation is likely important for maintaining mGal-2 protein function in an oxidative environment such as the gastrointestinal tract.
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Mayumi
M
Tamura
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Akari
A
Sasai
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Rika
R
Ozawa
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Masanori
M
Saito
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Kaori
K
Yamamoto
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Tomoharu
T
Takeuchi
Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Kazuo
K
Ohtake
Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8568, Japan.
Hiroaki
H
Tateno
Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, Ibaraki 305-8568, Japan.
Jun
J
Hirabayashi
Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Jun
J
Kobayashi
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan arata@josai.ac.jp.
Yoichiro
Y
Arata
D019943:Amino Acid Substitution; D000818:Animals; D037501:Galectin 2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry* / Q000378:metabolism; D051379:Mice; D020125:Mutation, Missense; D010084:Oxidation-Reduction
D037501:Galectin 2; D006861:Hydrogen Peroxide
Galectin-2; S-nitrosylation; cysteine; galectin; oxidation