Interaction of bovine erythrocyte spectrin with aminophospholipid liposomes.

Interaction of bovine erythrocyte spectrin with aminophospholipid (phosphatidylethanolamine, phosphatidylserine and their mixture) vesicles was studied by means of intrinsic fluorescence quenching and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene. Similarly as human and pig erythrocyte spectrin, bovine red blood cell spectrin interacts with vesicles prepared from these phospholipids. In model membranes, spectrin induced an increase of order parameter while in natural, red blood cell membranes spectrin binding was rather connected with a decrease in this parameter. The interaction of spectrin with the PE/PS vesicles was not affected by high concentrations of urea. These vesicles also did not protect spectrin from being denatured by urea.