title: Band 3 protein of the red cell membrane of the llama: crosslinking and cleavage of the cytoplasmic domain.
abstract: Comparative studies were done on the cytoplasmic domain of the band 3 protein in the red cell membranes of the the human and the llama. Two approaches were used: crosslinking with o-phenanthroline/CuSO4, and cleavage with 2-nitro-5-thiocyanobenzoate. o-Phenanthroline/CuSO4 crosslinks the band 3 polypeptide chains in the human; in contrast band 3 in the llama is minimally crosslinked by this agent. 2-Nitro-5-thiocyanobenzoate cleaves band 3 in the human into a 23,000-dalton fragment; a similar fragment is not generated from the llama band 3. These studies show that the cysteine residue located 23,000 daltons from the N-terminus of band 3 in the human involved in these reactions is unavailable for crosslinking and cleavage in the llama. Species differences in the cytoplasmic domain of band 3 may contribute to the unusual resistance of llama red cells to osmotic, chemical and physically-induced deformation.
mesh_terms: D000818:Animals; D001457:Anion Exchange Protein 1, Erythrocyte / Q000032:analysis*; D001188:Artiodactyla / Q000097:blood*; D002161:Camelids, New World / Q000097:blood*; D003432:Cross-Linking Reagents; D003593:Cytoplasm; D004910:Erythrocyte Membrane / Q000648:ultrastructure*; D010446:Peptide Fragments / Q000032:analysis; D010618:Phenanthrolines; D013045:Species Specificity; D013861:Thiocyanates
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D010618:Phenanthrolines; D013861:Thiocyanates; C008658:2-nitro-5-thiocyanobenzoic acid