Protein photo-folding and quantum folding theory

The rates of protein folding with photon absorption or emission and the cross section of photon-protein inelastic scattering are calculated from quantum folding theory by use of a field-theoretical method.All protein photo-folding processes are compared with common protein folding without the interaction of photons(non-radiative folding).It is demonstrated that there exists a common factor(thermo-averaged overlap integral of the vibration wave function,TAOI) for protein folding and protein photo-folding.Based on this finding it is predicted that(i) the stimulated photo-folding rates and the photon-protein resonance Raman scattering sections show the same temperature dependence as protein folding;(ii) the spectral line of the electronic transition is broadened to a band that includes an abundant vibration spectrum without and with conformational transitions,and the width of each vibration spectral line is largely reduced.The particular form of the folding rate-temperature relation and the abundant spectral structure imply the existence of quantum tunneling between protein conformations in folding and photo-folding that demonstrates the quantum nature of the motion of the conformational-electronic system.