Tags for labeling protein N-termini with subtiligase for proteomics.

Department of Pharmaceutical Chemistry , University of California, San Francisco, CA 94158-2330, USA.
Bioorganic & medicinal chemistry letters (Impact Factor: 2.65). 09/2008; 18(22):6000-3. DOI: 10.1016/j.bmcl.2008.08.044
Source: PubMed

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.

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