Copper(II)−dipicolylamine−coumarin sensor for maltosyltransferase assay

A Cu(II)−[di(2-methylpyridyl)methylamino]coumarin fluorescence turn-on sensor (Cu-1b) is designed to detect phosphate ion with Kass = 1.4 × 105 M–1 in HEPES buffer. Cu-1b is applied to probe the GlgE catalyzed maltose-transfer reaction of α-maltose-1-phosphate to α-1,4-glucan with concomitant release of phosphate ion in Mycobacterium tuberculosis.