biostudies-literatureAntos JMNIBIB NIH HHSNIAID NIH HHS10800-1https://www.ebi.ac.uk/biostudies/studies/S-EPMC2730784biostudies-literatureUnknown131(31)The unique reactivity of two sortase enzymes, SrtA(staph) from Staphylococcus aureus and SrtA(strep) from Streptococcus pyogenes, is exploited for site-specific labeling of a single polypeptide with different labels at its N and C termini. SrtA(strep) is used to label the protein's C terminus at an LPXTG site with a fluorescently labeled dialanine nucleophile. Selective N-terminal labeling of proteins containing N-terminal glycine residues is achieved using SrtA(staph) and LPXT derivatives. The generality of N-terminal labeling with SrtA(staph) is demonstrated by near-quantitative labeling of multiple protein substrates with excellent site specificity.Journal of the American Chemical SocietySite-specific N- and C-terminal labeling of a single polypeptide using sortases of different specificity.PMC2730784R01-AI057182R01-AI033456R21 EB008875R01 AI057182R21-EB008875R01 AI033456Chew GLPopp MWAntos JMGrotenbreg GMPloegh HLGuimaraes CPYoder NCfalseSite-specific N- and C-terminal labeling of a single polypeptide using sortases of different specificity.The unique reactivity of two sortase enzymes, SrtA(staph) from Staphylococcus aureus and SrtA(strep) from Streptococcus pyogenes, is exploited for site-specific labeling of a single polypeptide with different labels at its N and C termini. SrtA(strep) is used to label the protein's C terminus at an LPXTG site with a fluorescently labeled dialanine nucleophile. Selective N-terminal labeling of proteins containing N-terminal glycine residues is achieved using SrtA(staph) and LPXT derivatives. The generality of N-terminal labeling with SrtA(staph) is demonstrated by near-quantitative labeling of multiple protein substrates with excellent site specificity.2009-01-01T00:00:00Z2009 Aug2025-04-05T11:53:09.076Z2019-03-27T00:24:25ZS-EPMC27307841961062310.1021/ja902681k