Photo-CIDNP NMR methods for studying protein folding.
Chemically induced dynamic nuclear polarization (CIDNP) is a nuclear magnetic resonance phenomenon that can be used to probe the solvent-accessibility of tryptophan, tyrosine, and histidine residues in proteins by means of laser-induced photochemical reactions, resulting in significant enhancement of NMR signals. CIDNP offers good sensitivity as a surface probe of protein structure and is particularly powerful in time-resolved NMR measurements. Real-time, rapid-injection protein refolding experiments permit the observation of changes in the accessibility of specific residues during the folding process. CIDNP pulse-labeling gives information on the accessibility of residues in partially structured proteins (e.g., molten globule states) whose NMR spectra are broad and poorly resolved. Heteronuclear two-dimensional (15)N-(1)H CIDNP techniques allow identification of surface-accessible residues with improved resolution and sensitivity. These methods offer residue-specific structural and kinetic information on transient folding intermediates and other partially folded states of proteins that are not readily available from more routine NMR techniques.
Department of Chemistry, University of Oxford, Oxford Centre for Molecular Sciences, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK.
Ken Hun
KH
Mok
Peter J
PJ
Hore
D006639:Histidine / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D017510:Protein Folding; D012996:Solutions / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
D012996:Solutions; D014443:Tyrosine; D006639:Histidine; D014364:Tryptophan