Strange kinetic phase in the extremely early folding process of beta-lactoglobulin.
A continuous-wave probed laser-induced temperature jump system was constructed and applied to monitor the changes in tryptophan fluorescence of the beta-lactoglobulin during its folding; the kinetic phases were traced from 300 ns to 10 ms after a temperature jump. Notably, an early phase with typical squeezed-exponential characteristics, [exp[-(kt)(beta)], beta>1.0], was observed around several tens of microseconds after the temperature jump, which is actually the earliest phase ever observed for beta-lactoglobulin. This process can be explained by conformational shift occurring within the unfolded ensemble (U-->U'), which is followed by the non-native intermediate (I) formation of this protein.
Kamatari
Yuji O
YO
Division of Prion Research, Center for Emerging Infectious Diseases, Gifu University, Gifu 501-1194, Japan.
Nakamura
Hironori K
HK
Kuwata
Kazuo
K
D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007782:Lactoglobulins / Q000737:chemistry*; D017510:Protein Folding; D013050:Spectrometry, Fluorescence / Q000379:methods; D013696:Temperature; D014364:Tryptophan / Q000737:chemistry*
D007782:Lactoglobulins; D014364:Tryptophan