Hydrogen ion titration of lysozyme in alcohol-water solutions.
H+ titration curves of hen egg-white lysozyme were obtained at 0.15 I in the presence of small amounts (less than 15%) of methanol, ethanol and n-propanol. The acidity constants of two groups (whose pK values in water are, respectively, 42 and 3.5) are increased in water-alcohol mixtures in comparison to water. From the evaluation of these constants as a function of alcohol concentration and hydrocarbon chain length, it is suggested that these alcohols interact specifically with lysozyme. As pK values of 4.2 and 3.5 in water are generally assigned to Asp-101 and Asp-52 respectively, it seems that interaction occurs within the active site of the enzyme.
D000433:1-Propanol; D004529:Egg White; D000431:Ethanol; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008433:Mathematics; D000432:Methanol; D009113:Muramidase / Q000378:metabolism; D014867:Water
D014867:Water; D000431:Ethanol; D000433:1-Propanol; D009113:Muramidase; D000432:Methanol