Fast protein and RNA folding on a rough energy landscape.

摘要

A new design for the detection of mid-infrared and near-infrared transient spectra is presented. In this setup, time-varying IR spectra with 150 nanoseconds time resolution can be collected in a single sweep up to several milliseconds. Combining this approach with other experimental methods, the folding process of protein assembly, protein molecules, and RNA molecules was focused in this work. For the first time, time-resolved self-assembly of a light-harvesting protein complex was studied using the laser T-jump method. Experiment results show that this membrane protein can form different size of quaternary structures within millisecond time scale with a temperature-dependent rate coefficient. The fast folding of engineered lambda6-85 protein was also studied in this work. Interestingly, the folding kinetics of the fast mutant lambda Q33Y is probe-dependent, which is a new signature for downhill folding. The energy landscape of engineered RNA hairpin was also explored using temperature tuning method, which provides insight into the order of stem- and loop-formation in short RNA hairpins.