A new lipase as a pharmaceutical target for battling infections caused by Staphylococcus aureus : Gene cloning and biochemical characterization

Staphylococcus aureus lipases along with other cell‐wall‐associated proteins and enzymes ( i.e ., catalase, coagulase, protease, hyaluronidase, and β‐lactamase) play important roles in the pathogenesis of S. aureus and are important subject of drug targeting. The appearance of antibiotic‐resistant types of pathogenic S. aureus ( e.g ., methicillin‐resistant S. aureus , MRSA) is a worldwide medical problem. In the present work, a novel lipase from a newly isolated MRSA strain from a cow with subclinical mastitis was cloned and biochemically characterized. The mature part of the lipase was expressed in  Escherichia coli and purified by nickel affinity chromatography. It displays a high lipase activity at pH 8.0 and 25 °C using p ‐nitrophenyl palmitate and has a preference for medium–long‐chain substrates of p ‐nitrophenyl esters ( p NPC10–C16). Furthermore, in search of inhibitors, the effect of farnesol on the growth of S. aureus and the lipase activity was also studied. Farnesol inhibits the growth of S. aureus and is a mixed‐type inhibitor with K i and K i ′ values of 0.2 and 1.2 mmol L −1 , respectively. A lipase with known properties could not only serve as a template for developing inhibitors for S. aureus but also a valuable addition to enzyme toolbox of biocatalysis. The discovery of this lipase can be potentially important and could provide a new target for pharmaceutical intervention against S. aureus infection.