Immunochemical and biochemical study of a human Fcmu-like fragment (mu-chain disease).
An abnormal protein, from a petient with mu-chain disease has been studied: protein BUR. It is devoid of the F (ab'')2 mu fragment; molecular weight determinations and immunological data identify the protein as a F(c) 5 mu fragment. Similarly, carbohydrate determinations and proteolysis experiments relate it to a Fcmu fragment. Nevertheless, the protein, which tontains J-chain, lacks the entire covalently bonded structure of the F (c)5mu fragment. C-terminal analysis shows a tyrosine residue identical to the C-terminal amino acid of mu-chains. Sequence of the N-terminal region determined for 15 residues shows identity with sequence 338-352 and sequence 333-347 of two entire mu-chains previously studied. The relation of BUR to other heavy chain disease proteins is discussed.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D006362:Heavy Chain Disease / Q000276:immunology*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000032:analysis*; D007128:Immunoglobulin Fragments / Q000032:analysis; D007143:Immunoglobulin Heavy Chains / Q000032:analysis*; D007148:Immunoglobulin mu-Chains / Q000032:analysis*; D008970:Molecular Weight
D000596:Amino Acids; D002241:Carbohydrates; D007141:Immunoglobulin Fc Fragments; D007128:Immunoglobulin Fragments; D007143:Immunoglobulin Heavy Chains; D007148:Immunoglobulin mu-Chains