Probing conformational dynamics in biomolecules via chemical exchange saturation transfer: a primer.
Although Chemical Exchange Saturation Transfer (CEST) type NMR experiments have been used to study chemical exchange processes in molecules since the early 1960s, there has been renewed interest in the past several years in using this approach to study biomolecular conformational dynamics. The methodology is particularly powerful for the study of sparsely populated, transiently formed conformers that are recalcitrant to investigation using traditional biophysical tools, and it is complementary to relaxation dispersion and magnetization transfer experiments that have traditionally been used to study chemical exchange processes. Here we discuss the concepts behind the CEST experiment, focusing on practical aspects as well, we review some of the pulse sequences that have been developed to characterize protein and RNA conformational dynamics, and we discuss a number of examples where the CEST methodology has provided important insights into the role of dynamics in biomolecular function.
TIFR Centre for Interdisciplinary Sciences, Hyderabad, India. pramodh@tifrh.res.in.
Pramodh
P
Vallurupalli
Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, Canada.
Ashok
A
Sekhar
Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, Canada.
Tairan
T
Yuwen
Departments of Molecular Genetics, Biochemistry and Chemistry, University of Toronto, Toronto, ON, Canada. kay@pound.med.utoronto.ca.|Hospital for Sick Children, Program in Molecular Structure and Function, Toronto, ON, Canada. kay@pound.med.utoronto.ca.
Lewis E
http://orcid.org/0000-0003-3504-7995
LE
Kay
D001704:Biopolymers / Q000737:chemistry*; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry; D012313:RNA / Q000737:chemistry
D001704:Biopolymers; D011506:Proteins; D012313:RNA
CEST; Excited conformational states; Molecular dynamics; Slow conformational exchange