Glycosylation of human vaspin (SERPINA12) and its impact on serpin activity, heparin binding and thermal stability

Abstract

Vaspin is a glycoprotein with three predicted glycosylation sites at asparagine residues located in proximity to the reactive center loop and close to domains that play important roles in conformational changes underlying serpin function. In this study, we have investigated the glycosylation of human vaspin and its effects on biochemical properties relevant to vaspin function. We show that vaspin is modified at all three sites and biochemical data demonstrate that glycosylation does not hinder inhibition of the target protease kallikrein 7. Although binding affinity to heparin is slightly decreased, the protease inhibition reaction is still significantly accelerated in the presence of heparin. Glycosylation did not affect thermal stability.

Keywords: Adipokine; Glycosylation; Kallikrein 7; Serine protease; Serpin; Vaspin.