Estimation and Subcellular Distribution of Lecithinase Activity in Rat Intestinal Mucosa.

A method for the quantitative estimation of lecithinase has been developed using rat intestinal mucosa as the lecithinase source. Optimal conditions for lecithinase preparation and assay involve the use of buffered glycerol media with cysteamine and EDTA to stabilize the activity. Lecithin hydrolysis proceeds with apparent first order reaction kinetics when sonicated lecithin-oleate suspensions are used : in these conditions the rate of hydrolysis is proportional to the lecithinase concentration. The method gives satisfactory results in suboellular distribution studies. Fractionation by differential centrifugation and by treatment with polymixin or pH change strongly suggest that the enzyme activity is bound to ribosomal structures.