Interaction of biocompatible sugar based surfactant n-dodecyl β-D-maltoside with lysozyme

The interaction of lysozyme with biocompatible sugar-based surfactant n-dodecyl beta-D-maltoside (C(12)G(2)) was investigated by using surface tensiometry, synchronous and intrinsic fluorescence, circular dichroism (CD), Fourier-transform infra-red (FTIR), dynamic light scattering (DLS), and UV-visible absorption spectroscopies. The results of absorption spectra showed that formation of a complex has taken place between lysozyme and surfactant Surface tension measurements revealed that the complex was surface active and the interfacial properties of the complex such as pi(cmc) (the surface pressure at the cmc), Gamma(max) (the maximum surface excess) and A(min) (the minimum surface area per molecule) were calculated. The hyperchromic shift in the case of intrinsic and synchronous fluorescence measurements suggested that the fluorophores were more exposed on the addition of the surfactant to the protein. Far- and near-UV CD study in combination with FTIR measurements has shown that the interaction between lysozyme and C(12)G(2) resulted in the partial unfolding of protein for which alpha-helical contents have been analyzed and discussed. The increase in the size of the complex on the partial unfolding was also confirmed by DLS measurements. (C) 2015 Elsevier B.V. All rights reserved.