Solution 1H NMR characterization of substrate-free C. diphtheriae heme oxygenase: pertinence for determining magnetic axes in paramagnetic substrate complexes.

ABSTRACT: Proton 2D NMR was used to confirm in solution a highly conserved portion of the molecular structure upon substrate loss for the heme oxygenase from the pathogenic bacterium Corynebacterium diphtheriae, HmuO. The chemical shifts for the conserved portion of the structure are assessed as references for the dipolar shifts needed to determine the orientation of the paramagnetic susceptibility tensor, chi, in paramagnetic substrate complexes of HmuO. It is shown that the chemical shifts for the structurally conserved portion of substrate-free HmuO serve as excellent references for residues with only small to moderate sized dipolar shifts in the cyanide-inhibited substrate complex of HmuO, yielding an orientation of chi that is essentially the same as conventionally obtained from large dipolar s

SUBMITTER: Du Z 

PROVIDER: S-EPMC3008545 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature