Probing the local electronic and geometric properties of the heme iron center in a H-NOX domain.

ABSTRACT: Heme-Nitric oxide and/or OXygen binding (H-NOX) proteins are a family of diatomic gas binding hemoproteins that have attracted intense research interest. Here we employ X-ray absorption near-edge structure (XANES) spectroscopy to study the nitric oxide (NO) binding site of H-NOX. This is the first time this technique has been utilized to examine the NO/H-NOX signaling pathway. XANES spectra of wildtype and a point mutant (proline 115 to alanine, P115A) of the H-NOX domain from Thermoanaerobacter tengcongensis (Tt H-NOX) were obtained and analyzed for ferrous and ferric complexes of the protein. This work provides specific structural characterization of the solution state of several Tt H-NOX ferrous complexes (-unligated, -NO, and -CO) that were previously unavailable. Our iron K-edges indi

SUBMITTER: Dai Z 

PROVIDER: S-EPMC3137124 | biostudies-literature | 2011 Jun

REPOSITORIES: biostudies-literature