Synthesis, DNA-Binding and Antibacterial Activity of the Cell-Penetrating Peptide HIV-1 Tat (49-57)

The interaction of cell-penetrating peptide human immunodeficiency virus transacting activator of transcription, peptide Tat (49–57), which is the minimal transduction domain of human immunodeficiency virus Tat protein, with calf thymus DNA was investigated with UV/Vis spectroscopy, fluorescence spectroscopy, circular dichroism, and viscometry. Peptide Tat (49–57) could interact with DNA via the groove binding mode, which is accompanied with electrostatic interaction. The fluorescence experiments revealed that the binding constant was 2.63×105 l mol−1. The UV/Vis spectroscopy and circular dichroism results revealed that the interaction of Tat (49–57) binding with calf thymus DNA disturbed the acting force of accumulation between DNA base pairs. The antimicrobial study using Tat (49–57) against bacteria proved that Tat (49–57) possessed antimicrobial activity against both Gram-positive and Gram-negative bacteria with low hemolysis.