Fluorescence studies on the microenvironments of proteins in CO2-expanded reverse micellar solutions

The effect of compressed CO2 on the microenvironment of the two proteins (cytochrome c and RNase A) in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles was investigated using high-pressure steady-state fluorescence and time-resolved fluorescence. It is found that RNase A can shift from the water core to the interface of the reverse micellar cores as CO2 is dissolved, while cytochrome c maintains at the interface of the micellar core. As the pressure reaches to a high enough value, the proteins can be precipitated from the reverse micelle, which h s p ©