Probing the equilibrium unfolding of ketosteroid isomerase through xenon-perturbed 1H-15N multidimensional NMR spectroscopy.
We used xenon-perturbed 1H-15N multidimensional NMR to investigate the structural changes in the urea-induced equilibrium unfolding of the dimeric ketosteroid isomerase (KSI) from Pseudomonas putida biotype B. Three limited regions located on the beta3-, beta5- and beta6-strands of dimeric interface were significantly perturbed by urea in the early stage of KSI unfolding, which could lead to dissociation of the dimer into structured monomers at higher denaturant concentration as the interactions in these regions are weakened. The results indicate that the use of xenon as an indirect probe for multidimensional NMR can be a useful method for the equilibrium unfolding study of protein at residue level.
Lee
Hyeong Ju
HJ
Department of Chemistry, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea.
Moon
Hye Seon
HS
Jang
Do Soo
DS
Cha
Hyung Jin
HJ
Hong
Bee Hak
BH
Choi
Kwan Yong
KY
Lee
Hee Cheon
HC
D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D016958:Pseudomonas putida / Q000201:enzymology; D013251:Steroid Isomerases / Q000737:chemistry* / Q000378:metabolism; D014508:Urea / Q000737:chemistry; D014978:Xenon / Q000737:chemistry*
D014978:Xenon; D014508:Urea; D013251:Steroid Isomerases