Fig. 2.
Characterization of isopeptide bond formation. (A) Mass spectrometry of reconstitution between Cna peptide and SpyCatcher. The minor peak results from the His6-tag on SpyCatcher leading to some gluconylation (see SI Appendix). (B) Time course of SpyTag-MBP:SpyCatcher covalent complex formation, with each partner at 10 μM at 25 °C, pH 7.0 determined by SDS-PAGE. (C) Rate constant for SpyTag reaction, calculated from triplicate measurements (each point shown) of SpyCatcher depletion under conditions as in (B). The equation for the trend-line and the correlation coefficient are shown.