3D (13)C-(13)C-(13)C correlation NMR for de novo distance determination of solid proteins and application to a human alpha-defensin.

ABSTRACT: The de novo structure of an antimicrobial protein, human alpha-defensin 1 (HNP-1), is determined by combining a 3D (13)C-(13)C-(13)C (CCC) magic-angle spinning (MAS) correlation experiment with standard resonance assignment experiments. Using a short spin diffusion mixing time to assign intra-residue cross peaks and a long mixing time to detect inter-residue correlation peaks, we show that the 3D CCC experiment not only reduces the ambiguity of resonance assignment, but more importantly yields two orders of magnitude more long-range distances without recourse to existing crystal structures. Most of these distance constraints could not be obtained in a de novo fashion from 2D correlation spectra due to significant resonance overlap. Combining the distance constraints from the 3D CCC experim

SUBMITTER: Li S 

PROVIDER: S-EPMC2819753 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature