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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1986 Dec;83(23):8982–8986. doi: 10.1073/pnas.83.23.8982

Molecular dynamics simulations of cooling in laser-excited heme proteins.

E R Henry, W A Eaton, R M Hochstrasser
PMCID: PMC387058  PMID: 3024159

Abstract

In transient optical experiments the absorbed photon raises the vibrational temperature of the chromophore. In heme proteins at room temperature conversion of a 530-nm photon into vibrational energy is estimated to raise the temperature of the heme by 500-700 K. Cooling of the heme is expected to occur mainly by interacting with the surrounding protein. We report molecular dynamics simulations for myoglobin and cytochrome c in vacuo that predict that this cooling occurs on the ps time scale. The decay of the vibrational temperature is nonexponential with about 50% loss occurring in 1-4 ps and with the remainder in 20-40 ps. These results predict the presence of nonequilibrium vibrational populations that would introduce ambiguity into the interpretation of transient ps absorption and Raman spectra and influence the kinetics of sub-ns geminate recombination.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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