Isoelectric focusing of apo- and holo-transcobalamin present in human blood. Identification of a protein complexing with transcobalamin.
By means of isoelectric focusing we studied the factors influencing the isoelectric point of transcobalamin. Upon binding of cobalamin, the transcobalamin isopeptides M, X and S increase their isoelectric points by 0.4 pH units. Serum protein different from gammaglobulin changes the isoelectric point of transcobalamin, but the attachment of the transcobalamin-cobalamin complex to its acceptor is unchanged. Transcobalamin bound to auto-antibodies shows a characteristic pattern upon isoelectric focusing.
Department of Medicine and Haematology, Gentofte Hospital, Copenhagen, Denmark.
M
M
Hansen
E
E
Nexø
D000361:Agammaglobulinemia / Q000097:blood; D001059:Apoproteins / Q000097:blood* / Q000302:isolation & purification; D002850:Chromatography, Gel; D006801:Humans; D007525:Isoelectric Focusing; D007526:Isoelectric Point; D007700:Kinetics; D046911:Macromolecular Substances; D014155:Transcobalamins / Q000302:isolation & purification / Q000378:metabolism*
D001059:Apoproteins; D046911:Macromolecular Substances; D014155:Transcobalamins