Proteins of the camel erythrocyte membrane.

Electrophoresis on polyacrylamide gels containing dodecyl sulphate has revealed that the major proteins of the camel erythrocyte membrane are similar to those of the human and bovine species in both electrophoretic mobility and relative abundance. The major difference lies in the major intrinsic membrane protein of molecular weight approx. 100 000. In the camel, this protein has a higher apparent molecular weight than in the human and bovine species. The very high molecular weight water-soluble protein "spectrin" appears to be very tightly bound to the camel erythrocyte membrane, and is only partially extracted after prolonged low ionic strength dialysis. Total release of spectrin is only achieved by means of more drastic treatment such as incubation with urea, guanidine hydrochloride, sodium hydroxide of p-chloromercuribenzoate. Concurrent with the total release of spectrin, the camel cells undergo a shape change from flat ellipsoids to spheres, suggesting an important shape-maintaining role for spectrin in the erythrocytes of this species.