title: Thermal effect on Aequorea green fluorescent protein anionic and neutral chromophore forms fluorescence.
abstract: The emission behaviour of Aequorea green fluorescent protein (A-GFP) chromophore, in both neutral (N) and anionic (A) form, was studied in the temperature range from 20 °C to 75 °C and at pH = 7. Excitation wavelengths of 399 nm and 476 nm were applied to probe the N and A forms environment, respectively. Both forms exhibit distinct fluorescence patterns at high temperature values. The emission quenching rate, following a temperature increase, is higher for the chromophore N form as a result of the hydrogen bond network weakening. The chromophore anionic form emission maximum is red shifted, upon temperature increase, due to a charge transfer process occurring after A form excitation.
authors.affiliation: IN-CQFM, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal. andreasantos@fm.ul.pt
authors.forename: Andrea Martins
authors.initials: AM
authors.lastname: dos Santos
mesh_terms: D049452:Green Fluorescent Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: C485192:green fluorescent protein, Aequorea victoria; D049452:Green Fluorescent Proteins