N-Glycosylation is one of the most common cotranslational and post-translational modifications occurring in protein biosynthesis and plays a critical role in protein folding and structural diversification. Molecular dynamics studies of two benchmark systems, the NH2-terminal human CD2 adhesion domain (HsCD2ad), and the NH2-terminal rat CD2 adhesion domain (RnCD2ad) were carried out to investigate the energetic and dynamic effect of N-glycosylation on protein's stability. Our study revealed that N-glycosylation of HsCD2ad at the type I β-bulge turn strengthens the relevant hydrogen bonds, in particular, the hydrogen bond between Asn 65OD1-Thr67HG1. Dynamic cross correlation map analysis showed that nonglycosylated HsCD2ad has strong anticorrelated motions, whereas glycosylated HsCD2ad largely destroyed this anticorrelated motion. As a result, N-glycosylation energetically and dynamically stabilizes HsCD2ad. In contrast, N-glycosylation of RnCD2ad does not display observable effect on protein's stabilization. The current theoretical result is in excellent agreement with the recent thermodynamic experiment of Culyba et al. and indicates that enthalpy and entropy may both contribute to the stabilization of human CD2 by N-glycosylation.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry