GNPS Staphylococcus aureus lipopeptides

Septic arthritis, most often caused by Staphylococcus aureus (S. aureus), is a rapidly progressive and destructive joint disease with substantial mortality and morbidity. S. aureus lipoproteins (Lpps) are known to induce arthritis and bone destruction. Here, we aimed to investigate the bone resorptive effect of S. aureus Lpps in a murine arthritis model by intra-articular injection of purified S. aureus Lpps, synthetic lipopeptides, and live S. aureus strains. Analyses of the bone mineral density of the distal femur bone were performed. Intra-articular injection of both live S. aureus and purified S. aureus Lpps were shown to significantly decrease total- and trabecular the bone mineral density. HPLC-high resolution MS/MS analyses revealed that the Lpps expressed by S. aureus SA113 strain contain both diacyl and triacyl lipid moieties. Therefore, tryptic digestion of Lpps was carried out, and the resulting lipopeptides were analyzed by HPLC-MS/MS, in which peptide fragments and neutral losses of fatty acids were used to identify the lipopeptide structures. (doi: 10.3389/fmicb.2022.843799)