Development of highly efficient artilysins against Vibrio parahaemolyticus via virtual screening assisted by molecular docking

Novel artilysins by the fusions of phage lysin Lysqdvp001 (Lys) with outer membrane (OM) destabilizing peptides against Vibrio parahaemolyticus (V. parahaemolyticus) were designed and developed assisted by molecular docking. Eleven designed artilysins with predicted high affinity to lipopolysaccharide lipid-A (LPSA) of bacterial OM were selected, and eight designed artilysins after cloning and expression showed abilities to hydrolyze V. parahaemolyticus peptidoglycan (PG). After purification, highly purified artilysins HPP-Lys, SM29-Lys, EC2-Lys, M78-Lys, M21F-Lys and sTHA-Lys (purity >90%) with molecular weights of about 30–35 kDa were finally obtained. These recombinant artilysins, except HPP-Lys, displayed good antibacterial activities against V. parahaemolyticus. The sTHA-Lys exhibited the strongest antibacterial activity among these artilysins with 50 μg/mL of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) as well as a wider antibacterial spectrum. Besides, sTHA-Lys at MIC and 2 MIC completely inactivated V. parahaemolyticus in buffer and reduced 1.78 and 3.59 log10 CFU/mL of the bacteria in the oyster homogenates. Treatments of sTHA-Lys at MIC and 2 MIC also removed more than 82% of mature biofilms of V. parahaemolyticus and almost completely inhibited the formation of the bacterial biofilms. Engineered artilysins based on phage lysins and OM destabilizing peptides might be a promising candidate for antibacterial agent against V. parahaemolyticus contaminations in food industry.