Work

N-PEGylation of a Reverse Turn Is Stabilizing in Multiple Sequence Contexts, unlike N-GlcNAcylation

Year: 2011

Type: article

Abstract: The intrinsic stabilization of therapeutic proteins by N-glycosylation can endow them with increased shelf and serum half-lives owing to lower populations of misfolded and unfolded states, which are susceptible to aggregation and proteolysis. Conjugation of poly(ethylene glycol) (PEG) oligomers to nucleophilic groups on the surfaces of folded proteins (i.e., PEGylation) is a chemical alternative to N-glycosylation, in that it can also enhance the pharmacologic attributes of therapeutic proteins. However, the energetic consequences of PEGylation are currently not predictable. We find that PEGylation of an Asn residue in reverse turn 1 of the Pin WW domain is intrinsically stabilizing in several sequence contexts, unlike N-glycosylation, which is only stabilizing in a particular sequence context. Our thermodynamic data are consistent with the hypothesis that PEGylation destabilizes the protein denatured state ensemble via an excluded volume effect, whereas N-glycosylation-associated stabilization results primarily from native state interactions between the N-glycan and the protein.

Source: ACS Chemical Biology

DOI: 10.1021/cb200277u

Authors: Joshua L. Price, Evan T. Powers, Jeffery W. Kelly

Institution: Scripps Research Institute

Language: English

Topic: Protein Structure and Dynamics

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: green

Funders: National Institutes of Health, National Institute of General Medical Sciences

Awards: G3481252192, Understanding Beta-sheet structure in aqueous solution, The role of N-glycosylation on beta-sheet protein folding energetics