title: Tags for labeling protein N-termini with subtiligase for proteomics.
abstract: The peptide ligase subtiligase, derived from subtilisin, has been employed in the identification of protein N-termini in complex mixtures. Here, the peptide ester substrates for the ligation reaction were optimized with respect to solubility, resulting in greater incorporation of the N-terminal tags. Additionally, the quantitation of the incorporated tags was explored, and a 'click' chemistry-based derivatization provided the ability to quantitate the tag to low nanomolar concentrations by sandwich ELISA. These new tags should expand the utility of subtiligase for the proteomic study of N-termini.
authors.affiliation: Department of Pharmaceutical Chemistry , University of California, San Francisco, CA 94158-2330, USA.
authors.forename: Hikari A I
authors.initials: HA
authors.lastname: Yoshihara
authors.forename: Sami
authors.initials: S
authors.lastname: Mahrus
authors.forename: James A
authors.initials: JA
authors.lastname: Wells