Increasing the Assembly Efficacy of Peptidic β‑Sheets for a Highly-Sensitive HIV Detection

• Published in: Analytical chemistry (Washington) 2020-08, Vol.92 (16), p.11089-11094
• Main Authors: Cao, Hongyan, Liu, Ye, Sun, Hongyan, Li, Zulan, Gao, Yuan, Deng, Xinli, Shao, Yiming, Cong, Yulong, Jiang, Xingyu
• Format: Article
• Language: English
• Subjects: Assembly; Blood - virology; Chemistry; Congo Red - chemistry; Congo Red - metabolism; Enzyme-Linked Immunosorbent Assay - methods; Fluorescence; Fluorescent Dyes - chemistry; Fluorescent Dyes - metabolism; HIV; HIV - chemistry; HIV Core Protein p24 - blood; HIV Core Protein p24 - chemistry; HIV Core Protein p24 - metabolism; Human immunodeficiency virus; Humans; Limit of Detection; Mathematical analysis; Oligopeptides; Phenylalanine; Phenylalanine - chemistry; Protein Binding; Protein Conformation, beta-Strand - drug effects; Sheets
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.0c00951

Our recent publication illustrates the critical role of phenylalanine-mediated aromatic–aromatic interactions in determining the assembly of peptidic β-sheets. However, the effect of phenylalanine number on regulating the assembly efficacy of peptidic β-sheets remains poorly understood. We herein evaluate the assembly efficacy of β-sheets of a series of oligopeptides which contain 0, 1, 2, or 3 phenylalanine in their molecular backbones. In our assembly system, two phenylalanine (2F) is the minimum number for driving the assembly of β-sheets of oligopeptides. Oligopeptides with three phenylalanine (3F) show significantly increased assembly efficacy of β-sheets compared to that with 2F. These results suggest a positive correlation between the phenylalanine number and assembly efficacy of β-sheets. By improving the assembly efficacy of β-sheets, we further develop a highly sensitive HIV analytical system in which the specific binding of β-sheets with Congo Red induces enhanced fluorescence. For HIV p24 detection, the 3F-based analytical system (0.61 pg/mL) shows a significantly lower limit of detection (LOD) than the 2F-based analytical system (2.44 pg/mL), both of which are more sensitive than commercial ELISA (5 pg/mL) used in the clinic. This work not only illustrates the effect of phenylalanine number on regulating the assembly efficacy of β-sheets but also provides a guideline for the construction of a highly sensitive analytical system of disease diagnosis.