Transient On- and Off-Pathway Protein Folding Intermediate States Characterized with NMR Relaxation Dispersion.

ABSTRACT: The earliest events in the folding of a protein are in general poorly understood. We used NMR R₂ relaxation dispersion experiments to study transient local collapse events in the unfolded-state (U) conformational ensemble of apomyoglobin (apoMb). Local residual secondary structure (seen in regions corresponding to the A, D, E, and H helices of the folded protein) is largely unchanged over the pH range of 2.3-2.75, yet a significant pH-dependent increase in the conformational exchange contribution to the R₂ relaxation rate (R_ex) indicates that transient intramolecular contacts occur on a microsecond to millisecond time scale at pH 2.75. A comparison of ¹⁵N and ¹³CO relaxation dispersion data at pH 2.75 for residues

SUBMITTER: Meinhold DW 

PROVIDER: S-EPMC9793904 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature