Objective: To isolate and purify new antibiotic peptides from human lymphokine activated killer (LAK) cells.
Methods: Preparative Acid-Urea Polyacrylamide Gel Electrophoresis and Reverse Phase HPLC were performed to isolate and purify polypeptides from the acid extract of human LAK cells. The molecule weight was analyzed by Tricine-SDS-PAGE. Radial agar diffusion assay was used to analyze the antibacterial activities.
Results: Several antibiotic peptides were isolated. Two peptides were purified from fractions HLP-2, HLP-3, which had molecular weight of around 7.9 x 10(3) u and 4 x 10(3) u and were named HLP-2b and HLP-3a, respectively. Four peptides with molecular weight of 7.2 x 10(3) u, 10.4 x 10(3) u, 6.2 x 10(3) u and 6.2 x 10(3) u were almost purified and were named HLP-2a, HLP-2c, HLP-3b and HLP-3c, respectively. HLP-2b, HLP-2a, HLP-2c, HLP-3b and HLP-3c all had antimicrobial activities against S. Aureus and C. Albicans, and HLP-3a against S. Aureus only.
Conclusion: Human LAK cells contained a variety of antimicrobial peptides.