NMR studies on binding sites and aggregation-disassociation of fluorinated surfactant sodium perfluorooctanoate on protein ubiquitin.
The fluorinated surfactant sodium perfluorooctanoate (SPFO) could bind onto ubiquitin (UBQ) and induce the unfolding of UBQ. By using (15)N-edited heteronuclear single-quantum coherence (HSQC) NMR and (19)F NMR to monitor (15)N-labeled UBQ and SPFO, respectively, the binding sites and the aggregation process of SPFO on UBQ at various SPFO concentrations were observed. A detailed process from specific binding to cooperative binding of SPFO on UBQ, and a detailed structure change of UBQ upon the increase of SPFO concentration were obtained. The refolding of UBQ in UBQ-SPFO complex was carried out by adding cationic surfactant. It was shown that added cationic surfactants formed mixed micelles with SPFO and resulted in the dissociation of the UBQ-SPFO complex, and consequently, most ubiquitin could be refolded to its native state.
Lu
Run-Chao
RC
Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Guo
Xian-Rong
XR
Jin
Changwen
C
Xiao
Jin-Xin
JX
D001665:Binding Sites; D002210:Caprylates / Q000494:pharmacology*; D011232:Chemical Precipitation; D005466:Fluorocarbons / Q000494:pharmacology*; D008954:Models, Biological; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017510:Protein Folding / Q000187:drug effects; D013501:Surface-Active Agents / Q000494:pharmacology; D025801:Ubiquitin / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*
D002210:Caprylates; D005466:Fluorocarbons; D013501:Surface-Active Agents; D025801:Ubiquitin; C023036:perfluorooctanoic acid