Nondenaturing solubilization of β2 microglobulin from inclusion bodies by l-arginine

Expression of β2 microglobulin (β2m) in Escherichia coli resulted in formation of inclusion bodies. Attenuated total reflectance Fourier transform infrared analysis suggested a native-like secondary structure of β2m in the inclusion bodies. Nondenaturing solubilization of the native-like β2m from inclusion bodies was achieved using l-arginine solution, which enables an efficient recovery of β2m with little aggregation. Greater β2m solubilization from inclusion bodies was obtained at higher temperatures. Low-temperature solubilization yielded β2m with fluorescence properties identical to those of native β2m, but its secondary structure was slightly nonnative. Solubilization at moderate temperature gave β2m with an apparently native structure. We propose an efficient nondenaturing solubilization method combining l-arginine and moderate temperature.