GT MG517 activation by DOPG. Dependence of initial rates on DOPG concentration at two different lipid concentrations (DOPG + DOPC as neutral lipid). Conditions were as follows: 1 mm UDP-Glc, 1.25 mm (3.7 mol %) DOG in 20 mm HEPES, pH 8.0, 20 mm MgCl2, 20 mm CHAPS, 35 °C. Inset, dependence of kcat on [DOPG] at 12.5 mm (37 mol %) total DOPG + DOPC concentration.