NMR studies of a Glutaredoxin 2 from Clostridium oremlandii

Abstract

Grx2 is a glutaredoxin from gram positive bacterium Clostridium oremlandii (strain OhILAs), which is Cys-homolog of selenoprotein Grx1. Grx2 is a poor reductant of selenoprotein MsrA not like Grx1 while the reducing activity is reversed in two Grxs for Cys version of MsrA.

The wild-type Grx2 and the C15S mutant were overexpressed in E.coli and purified by affinity chromathography and gel filtration. The 3D NMR spectra was collected and assigned all the backbone chemical shifts including C[alpha], C[beta], C[Omicron], HN, and N of Grx2 and C15S mutant. The protein folding of two proteins were evaluated by circular dichroism.

Here we report the protein purification and NMR spectroscopic study of recombinant Grx2 and the C15S mutant. The HSQC spectrum of two proteins show chemical shift difference for residues 8-19, 52-55,66. The circular dichroism result shows that recombinant proteins are well folded.

The conformation of two proteins resembles the oxidized form (wild-type Grx2) and the reduced form (the C15S mutant). The residues showing chemical shift difference will join the conformational change of Grx2 upon a disulfide formation.