SPECIFIC VIBRATIONAL-RELAXATION IN PROTEIN MACROMOLECULES UNDER RESONANT INFRARED-LASER EXCITATION

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 mig ht be dependent on the spatial (conformational) structure of a macromo lecule. In the present work, this conclusion has been experimentally a nd theoretically tested for protein (albumin) macromolecules. High-pow er 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 infra red laser excitation cannot be explained by an equilibrium heating. Th e model of vibrational relaxation in a macromolecule with complex topo logy has been proposed.