Hidden electronic excited state of enhanced green fluorescent protein

2014 Fiscal Year Final Research Report

• Project/Area Number: 24550033
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Physical chemistry
• Research Institution: Toho University
• Principal Investigator: HOSOI Haruko 東邦大学, 理学部, 講師 (00313396)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: マルチプレックス二光子吸収分光法 / HBDI / eGFP / 電子励起S2状態 / 高振動励起S1状態

Outline of Final Research Achievements

Fluorescence imaging by two-photon excitation has attracted attention as a new imaging technique. However, fluorescence mechanism of two-photon excited fluorescent proteins is completely unknown. We measured two-photon absorption spectra of enhanced GFP (eGFP), which is the most important marker, and its model chromophore, HBDI, in various solvents by a multiplex two-photon absorption spectroscopy to clarify the fluorescence mechanism. The results indicate that the existence of a "hidden" excited state in the vicinity of the lowest excited singlet state of eGFP. We conclude that this is the origin of the discrepancy between the one-photon and two-photon excitation spectra of eGFP, which is well known in the field of biology.

Free Research Field

物理化学