QUB-2791: Identification of novel bioactive peptide from the Agalychnis annae skin secretions

Compared with other small molecule drugs, Antibacterial peptides (AMPs) found in the secretions of amphibians have broad-spectrum antibacterial activity. In addition, AMP and antibiotics have different killing mechanisms, therefore, AMP may be promising for solving the antibiotic resistance.<br><br>In this study, a novel peptide QUB-2791 was discovered from the skin secretion of Agalychnis anna using the "Shotgun" cloning, and then successfully synthesized by solid phase peptide synthesis.

Reversed-phase high performance liquid chromatography (RP-HPLC) and Matrix-assisted laser desorption/ionisation Time-of-flight (MALDI-TOF) mass spectrometry （MS）were employed to obtain the purified peptides. Finally, a series of bioactivity studies using pure QUB-2791 showed that QUB-2791 has a strong inhibitory effect against the growth of Gram-negative bacteria Escherichia coli. The minimum inhibitory concentration of QUB-2791 is 64 μM, and the minimum bactericidal concentration is 128 μM. QUB-2791 showed broad-spectrum anticancer activity against human cancer cells H23, U251MG, H157, and PC3 with the IC50 values of 10.97 μM, 3.749 μM, 8.757 μM, and 15.69 μM, respectively.