Role of non-Condon vibronic coupling and conformation change on two-photon absorption spectra of green fluorescent protein
2013 (English)In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 111, no 9-11, 1316-1321 p.Article in journal (Refereed) Published
Two-photon absorption spectra of green fluorescent proteins (GFPs) often show a blue-shift band compared to their conventional one-photon absorption spectra, which is an intriguing feature that has not been well understood. We present here a systematic study on one- and two-photon spectra of GFP chromophore by means of the density functional response theory and complete active space self-consistent field (CASSCF) methods. It shows that the popular density functional fails to provide correct vibrational progression for the spectra. The non-Condon vibronic coupling, through the localised intrinsic vibrational modes of the chromophore, is responsible for the blue-shift in the TPA spectra. The cis to trans isomerisation can be identified in high-resolution TPA spectra. Our calculations demonstrate that the high level ab initio multiconfigurational CASSCF method, rather than the conventional density functional theory is required for investigating the essential excited-state properties of the GFP chromophore.
Place, publisher, year, edition, pages
2013. Vol. 111, no 9-11, 1316-1321 p.
non-Condon vibronic coupling, two-photon absorption spectra, green fluorescent proteins (GFP)
IdentifiersURN: urn:nbn:se:kth:diva-122173DOI: 10.1080/00268976.2013.771800ISI: 000323409600026ScopusID: 2-s2.0-84882453867OAI: oai:DiVA.org:kth-122173DiVA: diva2:621179
QC 201309302013-05-142013-05-142013-09-30Bibliographically approved