Optimal Design, Characterization, and Structure-Function Analysis of Two Variants of Cathelicidin-2

Two variants of cathelicidin-2 were designed and their antimicrobial activity and structure–function relationship were evaluated and discussed. The MICs of LH22 and VL22 against Aeromonas hydrophila were < 0.98 and 15.6 μg/mL, respectively, and the MICs of VL22 against Staphylococcus aureus and Escherichia coli were 15.6 and 31.25 μg/mL, respectively. Large amounts of nucleic acids and proteins were detected in the supernatant of culture medium after treatment with LH22 and VL22. Apparent wrinkled and distorted cell morphology and apparent pores could be observed by SEM in the treated Aeromonas hydrophila with the two peptides. These two peptides also showed the neutralizing activity against LPS.