Cutinase from Amycolatopsis mediterannei: Marked activation and stabilisation in Deep Eutectic Solvents

Amycolatopsis mediterranei cutinase (AmCut) has potential biocatalytic applications in plastics degradation and ester synthesis. Deep Eutectic Solvents (DES) are next generation biodegradable solvents for biocatalysis. However, the behaviour of cutinase enzymes in DES is little studied. Herein, we examine the effect of selected DES, and their components, on AmCut activity and stability. Low amounts (10% v/v) of DES (choline chloride:glycerol; 1:1 mol ratio) caused striking activation of AmCut (over 2-fold). Further examination showed that the choline chloride component of DES caused the observed activation. This is the first report of activation of a cutinase by a small molecule. At higher concentrations (50% v/v), DES composed of choline chloride with glycerol as hydrogen bond donor dramatically increased the thermostability of AmCut - the enzyme lost no activity after incubation at 50 °C for 2 h. The biotechnological utility and physiological relevance of choline chloride activation and stabilisation is discussed.