Specific vibrational relaxation in protein macromolecules under resonant infrared laser excitation

摘要

The effect of spatially selective thermal dissociation under infrared laser excitation, found in cellulose nitrate macromolecules, leads to the conclusion that the rate and the way of vibrational relaxation might be dependent on the spatial (conformational) structure of a macromolecule. In the present work, this conclusion has been experimentally and theoretically tested for protein (albumin) macromolecules. High-power tunable infrared parametric oscillator (5000-2500 cm(-1)) and anti-stokes Raman spectroscopy method have been used in experiments. It was shown that changes in anti-Stokes spectra of protein, caused by infrared laser excitation cannot be explained by an equilibrium heating. The model of vibrational relaxation in a macromolecule with complex topology has been proposed. [References: 5]