Abstract 2851 Targeting the orphan PTP in Streptococcus pyogenes through combined in silico and in vitro screening

S. pyogenes is a gram-positive human pathogen that has been linked to various diseases from skin infections to necrotizing fasciitis and rheumatic heart disease.The orphan protein tyrosine phosphatase from S. pyogenes (SP-PTP) was recently identified as a major virulence regulator and a key determinant of pathogenesis.About 50% of the genes in this bacteria, including those involved in virulence, appear to be regulated by SP-PTP.Previous studies have shown that the knockdown of SP-PTP leads to reduced growth, impaired cell division, and decreased ability to invade host cells, exhibiting the importance of this protein in S. pyogenes pathogenesis.With SP-PTP presenting as a central protein in pathogenesis, it is a viable target for new antibiotics, specifically targeting bacterial virulence.To this end, this project aims to identify small-molecule inhibitors of SP-PTP.A crystal structure of SP-PTP is currently available showing high similarity with other low molecular weight PTPs (LMWPTPs).Using this structure, computational analysis of potential druggable pockets was performed.Consensus pockets, including close to the active site, were identified using FTMap and DoGSite and further validated by molecular dynamics druggability simulations.A virtual screening of a panel of FDA-approved drugs was also performed targeting these pockets.Concurrently, a virtual screening of drug-like molecules (3.5 M compounds from the ZINC library) is also ongoing.Combined with the virtual screens, fragment screening by fluorine NMR and drug libraries in vitro have also identified preliminary hits.Future directions include validating these hits through proteinobserved NMR and co-crystallizing SP-PTP with binders and potential inhibitors.