A single N-acetylgalactosamine residue at threonine 106 modifies the dynamics and structure of interferon ?2a around the glycosylation site.

ABSTRACT: Enzymatic addition of GalNAc to isotopically labeled IFN?2a produced in Escherichia coli yielded the O-linked glycoprotein GalNAc?-[(13)C,(15)N]IFN?2a. The three-dimensional structure of GalNAc?-IFN?2a has been determined in solution by NMR spectroscopy at high resolution. Proton-nitrogen heteronuclear Overhauser enhancement measurements revealed that the addition of a single monosaccharide unit at Thr-106 significantly slowed motions of the glycosylation loop on the nanosecond time scale. Subsequent addition of a Gal unit produced Gal(?1,3)GalNAc?-[(13)C,(15)N]IFN?2a. This extension resulted in a further decrease in the dynamics of this loop. The methodology used here allowed the first such description of the structure and dynamics of an O-glycoprotein and opens the way to the study of this class of proteins.

SUBMITTER: Ghasriani H 

PROVIDER: S-EPMC3537019 | biostudies-literature | 2013 Jan

REPOSITORIES: biostudies-literature