Fig. 3

The thin-layer chromatography of the lipids extracted from the samples of mucin binding protein (MBP) subjected to nitrous acid (HONO) hydrolysis. Lane 1, lipids released from the MBP isolated by wheat germ agglutinin (WGA)-affinity column (11). Lane 2, lipids released from the MBP obtained from Triton X-100-insoluble mucosal membranes. Lane 3, phosphatidylinositol standard. The same samples subjected to mock hydrolysis with HONO₂ afforded organic solvent extract free of lipids. The thin-layer chromatography of the chloroform/methanol/HCl (2:1:0.01, v/v/v) extract of the hydrolysis products with HONO and HONO₂ was performed on high performance thin layer chromatography (HPTLC) silica gel 60 plates in chloroform/methanol/water (65:25:5, v/v/v) and visualized by charring with 30% ammonium bisulfate.