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Updated: Nov 1, 2025

Green Fluorescent Protein-based Expression Screening of Membrane Proteins in Escherichia coli
Published on: January 6, 2015
New Red-Emitting Chloride-Sensitive Fluorescent Protein with Biological Uses
Rafael Salto1, Maria D Giron1, Virginia Puente-Muñoz2
1Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), University of Granada, Cartuja Campus, 18071 Granada, Spain.
Abstract:
A new chloride-sensitive red fluorescent protein derived from Entacmaea quadricolor is described. We found that mBeRFP exhibited moderate sensitivity to chloride and, via site-directed mutagenesis (S94V and R205Y), we increased the chloride affinity by more than an order of magnitude (kd = 106 ± 6 mM) at physiological pH. In addition, cis-trans isomerization of the chromophore produces a dual emission band with different chloride sensitivities, which allowed us to develop a ratiometric methodology to measure intracellular chloride concentrations.

