The breakdown of spectrin produced by ultrasonication

The application of carefully controlled ultrasonication to human erythrocyte membranes (ghosts) has been found to produce a selective breakdown of the two spectrin polypeptides. This breakdown increases with the time and the intensity of ultrasonication. The 240 000 molecular weight spectrin polypeptide is slightly more susceptible to ultrasonication than the 220 000 molecular weight polypeptide. Isolated spectrin behaves in an identical manner when ultrasonicated. When highly purified samples of spectrin are ultrasonicated the progressive reduction of the molecular weight of the products with increasing time is clearly apparent.