Use of time-resolved FRET to validate crystal structure of complement regulatory complex between C3b and factor H (N terminus).

ABSTRACT: Structural knowledge of interactions amongst the ~ 40 proteins of the human complement system, which is central to immune surveillance and homeostasis, is expanding due primarily to X-ray diffraction of co-crystallized proteins. Orthogonal evidence, in solution, for the physiological relevance of such co-crystal structures is valuable since intermolecular affinities are generally weak-to-medium and inter-domain mobility may be important. In this current work, Förster resonance energy transfer (FRET) was used to investigate the 10 μM K(D) (210 kD) complex between the N-terminal region of the soluble complement regulator, factor H (FH1-4), and the key activation-specific complement fragment, C3b. Using site-directed mutagenesis, seven cysteines were introduced individually at potentially inf

SUBMITTER: Pechtl IC 

PROVIDER: S-EPMC3302653 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature