This paper describes the development of an enzymatic assay system for the identification of specific inhibitors of sortase, a transpeptidase that cleaves surface proteins of Gram-positive bacteria, from Staphylococcus aureus ATCC 6538p for antibacteri...
This paper describes the development of an enzymatic assay system for the identification of specific inhibitors of sortase, a transpeptidase that cleaves surface proteins of Gram-positive bacteria, from Staphylococcus aureus ATCC 6538p for antibacterial drug discovery. The coding region of the enzyme was amplified with the exception of the N-terminal membrane anchor sequence, cloned into a vector providing His-Patch-thioredoxin-tag at the N-terminus, expressed in Escherichia coli, and purified by metal chelate affinity chromatography. The enzyme activity was determined by quantifying increased fluorescence intensity upon cleavage of synthetic Dabcyl-QALPETGEE-Edans peptide. The results suggest that the developed in vitro assay system can be used in the search for sortase inhibitors in a short period of time.