DECREASED ROTATIONAL DIFFUSION OF BAND-3 IN MELANESIAN OVALOCYTES FROM PAPUA-NEW-GUINEA

Melanesian ovalocytes from Papua New Guinea have an N-terminal extension of the band 3 polypeptide (Jones. G.L. Edmunson, H.M., Wesche. D..Saul. A. 1990. Biochim. Biophys. Acta 1096: 33-40). The ovalocytes showed a threefold increase in shear elastic modulus as determined by micropipette aspiration measurements of membrane rigidity. Time-resolved phosphorescence anisotropy has been used to study the rotational freedom of band 3 in membranes prepared from ovalocytes. The ovalocytic polymorphism was found to be associated with a marked decrease in the rotational mobility of band 3. This may indicate participation of band 3 in large homoaggregates or in complexes with other proteins at the cytoplasmic surface. There was no morphological clustering of band 3 detectable by immunofluorescence microscopy.