Influence of Anhydrous Hydrogen Fluoride on Hen Egg-White Lysozyme. I. Effects on Native Hen Egg-White Lysozyme

The influences of anhydrous hydrogen fluoride on the native form of hen egg-white lysozyme under standard conditions of peptide synthesis were investigated by measuring the enzymatic activities of materials recovered from mixtures of anhydrous hydrogen fluoride and hen egg-white lysozyme. The enzymatic activity of hen egg-white lysozyme gradually decreased on incubation with anhydrous hydrogen fluoride at a given temperature. After incubation of the mixture at 0 °C for 60 min, at least three fractions could be separated by gel-filtration on Sephadex G-50. One of these was eluted in the same position as native lysozyme and was fully active enzymatically. Its ultra-violet, and circular dichroism absorptions were identical with those of native lysozyme, and the tetragonal crystals obtained from this fraction could not be distinguished from those of native lysozyme.