Effect of the Confinement on the Properties of Mixed Polar Solvents Sequestrated. The case of Enzymatic Catalysis Performed in Nonaqueous AOT Reverse Micelle

DURANTINI A.; FALCONE R.D.; SILBER J.J.; CORREA N.M.

Chemphyschem

WILEY-V C H VERLAG GMBH

Lugar: Weinheim; Año: 2016 vol. 17 p. 1678 - 1685

1439-4235

The influence of different glycerol, N,N-dimethylformamide(DMF) and water mixtures encapsulated in 1,4-bis-2-ethylhexylsulfosuccinate(AOT)/n-heptane reverse micelles (RMs) on theenzymatic hydrolysis of 2-naphthyl acetate by a-chymotrypsinis demonstrated. In the case of the mixtures with DMF andprotic solvents it has been previously shown, using absorption,emission and dynamic light-scattering techniques, that solventsare segregated inside the polar core of the RMs. Proticsolvents anchor to the AOT, whereas DMF locates to the polarcore of the aggregate. Thus, DMF not only helps to solubilizethe hydrophobic substrate, increasing its effective concentrationsbut surprisingly, it does not affect the enzyme activity.The importance of ensuring the presence of RMs, encapsulationof the polar solvents and the corrections by substrate partitioningin order to obtain reliable conclusions is highlighted.Moreover, the effect of a constrained environment on solvent?solvent interactions in homogenous media and its impact onthe use of RMs as nanoreactors is stressed.