Probing interaction of a fluorescent ligand with HIV TAR RNA.
Trans-activator of Transcription (Tat) antagonists could block the interaction between Tat protein and its target, trans-activation responsive region (TAR) RNA, to inhibit Tat function and prevent human immunodeficiency virus type 1 (HIV-1) replication. For the first time, a small fluorescence ligand, ICR 191, was found to interact with TAR RNA at the Tat binding site and compete with Tat. It was also observed that the fluorescence of ICR 191 could be quenched when binding to TAR RNA and recovered when discharged via competition with Tat peptide or a well-known Tat inhibitor, neomycin B. The binding parameters of ICR 191 to TAR RNA were determined through theoretical calculations. Mass spectrometry, circular dichroism and molecular docking were used to further confirm the interaction of ICR 191 with TAR RNA. Inspired by these discoveries, a primary fluorescence model for the discovery of Tat antagonists was built using ICR 191 as a fluorescence indicator and the feasibility of this model was evaluated. This ligand-RNA interaction could provide a new strategy for research aimed at discovering Tat antagonists.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China; Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry (Shaanxi Normal University), Ministry of Education, Xi'an 710062, China.
Liang
L
Qi
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Jing
J
Zhang
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Tian
T
He
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Yuan
Y
Huo
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China; Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry (Shaanxi Normal University), Ministry of Education, Xi'an 710062, China. Electronic address: zqzhang@snnu.edu.cn.
Zhi-Qi
ZQ
Zhang
D000585:Aminacrine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D002942:Circular Dichroism; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry / Q000378:metabolism*; D005601:Framycetin / Q000737:chemistry / Q000378:metabolism; D016325:HIV Long Terminal Repeat; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
D005456:Fluorescent Dyes; D012367:RNA, Viral; D054322:tat Gene Products, Human Immunodeficiency Virus; C049476:ICR 191-OH; D005601:Framycetin; D000585:Aminacrine
Fluorescence indicator; ICR 191; TAR RNA; Tat antagonists; Tat protein