Nanosecond-time-resolved infrared spectroscopic study of fast relaxation kinetics of protein folding by means of laser-induced temperature-jump

• 来源期刊: 中国物理(英文版)
• 关键词: protein folding sub-microsecond laser-induced temperature-jump transient infrared spectrum dynamics cytochrome C
• 年，卷（期）: 2005,（12）
• 页码范围: 2484-2490
• 页数: 7页
• 语种: 英文

摘要

Elucidating the initial kinetics of folding pathways is critical to the understanding of the protein folding mechanism. Transient infrared spectroscopy has proved a powerful tool to probe the folding kinetics. Herein we report the construction of a nanosecond laser-induced temperature-jump (T-jump) technique coupled to a nanosecond timeresolved transient mid-infrared (mid-IR) spectrometer system capable of investigating the protein folding kinetics with a temporal resolution of 50 ns after deconvolution of the instrumental response function. The mid-IR source is a liquid N2 cooled CO laser covering a spectral range of 5.0μm (2000 cm-1) ～ 6.5μm (1540 cm-1). The heating pulse was generated by a high pressure H2 Raman shifter at wavelength of 1.9μm. The maximum temperature-jump could reach as high as 26±1℃. The fast folding/unfolding dynamics of cytochrome C was investigated by the constructed system,providing an example.