Abstract
Accelerated spontaneous deamidation of asparagine 373 and subsequent conversion into an isoaspartate has been shown to attenuate the binding of histo blood group antigens (HBGAs) to the protruding domain (P-domain) of the capsid protein of a prevalent norovirus strain (GII.4). Here, we link an unusual backbone conformation of asparagine 373 to its fast site-specific deamidation. NMR spectroscopy and ion exchange chromatography have been used to monitor the deamidation reaction of P-domains of two closely related GII.4 norovirus strains, specific point mutants, and control peptides. MD simulations over several microseconds have been instrumental to rationalize the experimental findings. While conventional descriptors such as available surface area, root-mean-square fluctuations, or nucleophilic attack distance fail as explanations, the population of a rare syn-backbone conformation distinguishes asparagine 373 from all other asparagine residues. We suggest that stabilization of this unusual conformation enhances the nucleophilicity of the backbone nitrogen of aspartate 374, in turn accelerating the deamidation of asparagine 373. This finding should be relevant to the development of reliable prediction algorithms for sites of rapid asparagine deamidation in proteins.
| Original language | English |
|---|---|
| Journal | Biochemistry |
| Volume | 62 |
| Issue number | 5 |
| Pages (from-to) | 1032-1043 |
| Number of pages | 12 |
| ISSN | 0006-2960 |
| DOIs | |
| Publication status | Published - 07.03.2023 |
Funding
Financial support by the Max Planck Society for the Advancement of Science and the International Max Planck Research School (IMPRS) for Advanced Methods in Process and Systems Engineering, Magdeburg, Germany, to M. Stein and E. Schulze-Niemand is gratefully acknowledged. M. Stein acknowledges funding from COST Action CA20113 “ProteoCure”, supported by EU COST (European Cooperation in Science and Technology). R. Creutznacher acknowledges funding by the Deutsche Forschungsgemeinschaft (494746248). We would like to thank Chiara Cabrele for comments and suggestions on the project. This research was funded by the Deutsche Forschungsgemeinschaft (DFG) via grant Pe494/12-2 (T. Peters) within the research unit FOR2327 (ViroCarb). T. Peters thanks the State of Schleswig-Holstein for supplying the NMR infrastructure (European Funds for Regional Development, LPW-E/1.1.2/857).
