Study of interaction of a cationic protein with a cationic surfactant using solvation dynamics

Lysozyme, a cationic protein binds a cationic surfactant cetyltrimethylammonium bromide (CTAB) because of hydrophobic effect. Solvation dynamics of coumarin 153 (C153) has been studied in a solution containing 0.5 wt% lysozyme and 0.8 mM CTAB. C153 does not bind to the native lysozyme and CTAB individually at these concentrations. However, C153 resides inside the lysozyme-CTAB aggregate. In this aggregate, solvation time of C153 is 600 ps which is slower than those in lysozyme alone (90 ps) and CTAB micelle alone (230 ps).