title: Fluorescent CD4 probe for potential HIV-1 gp120 protein detection.
abstract: A fluorescently modified CD4 domain 1 (mD1) protein has been designed and elaborated in an in vitro expression system. This fluorescent probe contains a Förster resonance energy transfer (FRET) pair, which uses a tryptophan residue as the fluorescence donor and an acridon-2-ylalanine (Acd) as the acceptor. When excited at 260nm, energy was transferred from tryptophan to the Acd residue of mD1, and emitted fluorescence at 420nm. This fluoresence was quenched after Evans blue (EB) inhibitor or HIV-1 gp120 protein binding, presumably as a consequence of changes in the distance and dipole orientation between the donor and acceptor; the emission intensity at 420nm decreased in a concentration-dependent fashion. This fluorescent CD4 probe could be developed into a novel tool for HIV-1 gp120 protein detection. It also could be used to screen small molecules that inhibit the gp120-CD4 interaction.
authors.affiliation: Center for BioEnergetics, Biodesign Institute, and Department of Chemistry and Biochemistry, Arizona State University, 1001 South McAllister Avenue, Tempe, AZ 85287, USA.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Center for BioEnergetics, Biodesign Institute, and Department of Chemistry and Biochemistry, Arizona State University, 1001 South McAllister Avenue, Tempe, AZ 85287, USA.
authors.forename: Poulami
authors.initials: P
authors.lastname: Talukder
authors.affiliation: Center for BioEnergetics, Biodesign Institute, and Department of Chemistry and Biochemistry, Arizona State University, 1001 South McAllister Avenue, Tempe, AZ 85287, USA.
authors.forename: Sidney M
authors.initials: SM
authors.lastname: Hecht
authors.affiliation: Center for BioEnergetics, Biodesign Institute, and Department of Chemistry and Biochemistry, Arizona State University, 1001 South McAllister Avenue, Tempe, AZ 85287, USA. Electronic address: shengxi.chen.1@asu.edu.
authors.forename: Shengxi
authors.initials: S
authors.lastname: Chen
mesh_terms: D015704:CD4 Antigens / Q000737:chemistry* / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D005456:Fluorescent Dyes / Q000737:chemistry*; D015699:HIV Envelope Protein gp120 / Q000032:analysis*; D015497:HIV-1 / Q000378:metabolism*; D006801:Humans; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D014364:Tryptophan / Q000737:chemistry
chemical_list: D015704:CD4 Antigens; D005456:Fluorescent Dyes; D015699:HIV Envelope Protein gp120; C514793:gp120 protein, Human immunodeficiency virus 1; D014364:Tryptophan
keywords: Acridon-2-ylalanine; FRET; Fluorescent CD4; HIV detection; gp120