Characterization of internal lipids from wool

Abstract

The internal lipids of wool were isolated after solubilizing the wool keratin with a mixture of papain and dithioerythritol 1.4. Thin layer chromatography of the internal lipids was applied to classify the extracted components. The internal wool lipids gave 11 spots of which some were identified as cholesterol and free fatty acids, C-16 and C-18 being predominant. A very small amount of triglycerides and cholesterol esters were also found. A characteristic difference between internal wool lipids and wool wax appears to be the limited number of well defined components of which free cholesterol and fatty acids constitute the main bulk. Furthermore another feature of keratin membrane lipids is the extremely reduced phospholipid: cholesterol ratio of 0.3. The internal lipids originate mainly from the cell membrane complex of the fiber. The existence of a chemically modified bilayer membrane structure without the essential phospholipids must be taken into consideration.