<prompt> Membrane integrity of RBC is due toG-proteinHaemoglobinSpectrinAnkyrin  <response>: C i.e. SpectrinWhen the membrane of RBC are analyzed by SDS- PAGE, the protein with slowest migration hence highest molecular weight being designated band 1 or spectrin. Spectrin is the major protein of RBC cytoskeleton responsible for integrity of RBC membraneQ. It has 1a and 23 chains forming triple stranded a -helix. At least 4 binding sites can be defined in spectrin for 1 Selfassociation 2 Ankyrin band 2.1 3 Actin band 5, and 4 Protein 4.1SpectrinQ, ankyrin Pyramidal shaped and other peripheral membrane protein eg. actin, protein 4.1, adducin, tropomyosin 4.9 help determine the shape, flexibility of RBC. 