Conformational fluctuations in a green fluorescent protein-like Akane family protein: a high-pressure fluorescence study at 0.1–700 MPa. Issue 2 (3rd April 2017)

• Record Type: Journal Article
• Authors: Maeno, Akihiro; Kato, Yuko; Jimbo, Mitsuru; Amada, Kei; Mita, Hajime; Akasaka, Kazuyuki
• Is Part Of: High pressure research. Volume 37:Issue 2(2017)
• Page Start: 224
• Page End: 232
• Publication Date: 2017-04-03
• Subjects: GFP-like protein -- red-brown-Akane from octocoral -- green and red emission -- high pressure fluorescence -- conformational equilibrium -- unfolding; High pressure (Science) -- Periodicals; High pressure (Technology) -- Periodicals; 536.41
• DOI: 10.1080/08957959.2017.1293049
• Languages: English
• ISSNs: 0895-7959

Abstract

ABSTRACT: We have investigated conformational fluctuations in a new green fluorescent protein(GFP)-like protein rb-Akane found in a red-brown-colored octocoral, Scleronephthya gracillima (Kuekenthal)), with high pressure fluorescence spectroscopy at 0.1–700 MPa. Besides the green fluorescence at 510 nm, two red fluorescence peaks are observed at 590 and 629 nm, the relative intensity of which varies reversibly with pressure. The phenomenon is interpreted as representing the cis–trans isomerization of the chromophore accompanied by the conformational transition between two sub-states of the red fluorescence form of rb-Akane. The two sub-states are separated only marginally in free energy (Δ G 0 = 1.9 ± 0.4 kJ mol −1 ), but significantly in partial molar volume (Δ V 0 = −19.8 ± 1.4 ml mol −1 ) at 0.1 MPa (pH 7.5, 25°C). Above 500 MPa, the fluorescence at λ max 629 nm undergoes another reversible change with pressure, showing the onset of unfolding.