Distinct residual and disordered structures of alpha-synuclein analyzed by amide-proton exchange and NMR signal intensity.
Related Articles Distinct residual and disordered structures of alpha-synuclein analyzed by amide-proton exchange and NMR signal intensity.
Biochim Biophys Acta Proteins Proteom. 2020 Jun 01;:140464
Authors: Okuwaki R, Shinmura I, Morita S, Matsugami A, Hayashi F, Goto Y, Nishimura C
Abstract
The residual solution structures of two alpha-synuclein mutants, A30P and A53T, observed in family members of patients with Parkinson's disease were compared with that of wild-type by NMR. The A53T substitution had been shown to accelerate fibril formation of alpha-synuclein, whereas the A30P mutation has the negative and positive effects on the formation of the fibril and spherical oligomer, respectively. The remaining structure was analyzed via amide-proton exchange and signal intensity measurements using NMR. Amide-proton exchange was used for both the calculation of kex values and ratio of kex at different temperatures. Effects of the A30P (N-terminal region) mutation were observed at the C-terminal region as a more flexible structure, suggesting that long-range interactions exist between the N- and C-terminal regions in alpha-synuclein. In addition, the N-terminal region adopted a more rigid structure in the A53T and A30P mutants than in the wild-type. It was concluded that the structural change caused by the mutations is related to the formation of a beta-hairpin at the initiation site of the N-terminal core structure. Furthermore, the signal intensity was used to estimate the rigidity of the structure. Higher signal intensities were observed for A30P at the 112, 113, and 116C-terminal residues, suggesting that this region adopts more flexible structure. The ratio of the intensities at different temperatures indicated more flexible or rigid structures in the N-terminal region of A30P than in that of wild-type. Thus, using different approaches and temperatures is a good method to analyze residual structure in intrinsically disordered proteins.
PMID: 32497661 [PubMed - as supplied by publisher]
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