Conformational change study of dengue virus NS2B-NS3 protease using 19F NMR spectroscopy.
The dengue virus NS2B-NS3 protease (NS2B-NS3p), an important antiviral target for drug development, has been reported to adopt an open or closed conformation in crystal structures with different NS2B C-terminus (NS2Bc) positioning. In solution, nevertheless, NS2B-NS3p forms a mixture of open, closed and maybe other intermediate conformations, which is difficult to characterize using conventional biophysical and biochemical techniques. In this study, we developed a new strategy to analyze these conformational changes using (19)F NMR spectroscopy. Low pH or bovine pancreatic trypsin inhibitor (BPTI) binding promote the conformation change from open to closed, showing the importance of charge forces in the interaction between NS2Bc and NS3p. The mutation H51A impairs the charge interaction and the pH dependence of the conformational changes. It stabilizes the open conformation, while the addition of BPTI still converts NS2B-NS3p from open to closed conformation.
High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
Lei
L
Zhu
High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
Jing
J
Yang
Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kai Yuan Avenue, Science Park, Guangzhou, Guangdong 510530, China.
Hua
H
Li
High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
Hongbin
H
Sun
Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, 190 Kai Yuan Avenue, Science Park, Guangzhou, Guangdong 510530, China. Electronic address: liu_jinsong@gibh.ac.cn.
Jinsong
J
Liu
High Magnetic Field Laboratory, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China. Electronic address: junfeng@hmfl.ac.cn.
Junfeng
J
Wang
D003198:Computer Simulation; D005461:Fluorine / Q000032:analysis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D011487:Protein Conformation; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000648:ultrastructure*; D055672:Static Electricity; D000085242:Viral Proteases
D005461:Fluorine; D012697:Serine Endopeptidases; C504449:NS3 protease, dengue virus; D000085242:Viral Proteases
(19)F nuclear magnetic resonance spectroscopy; BPTI; Charge interactions; Conformational change; Dengue virus NS2B-NS3 protease