Congophilicity (Congo red affinity) of different beta2-microglobulin conformations characterized by dye affinity capillary electrophoresis.
The amyloidogenic protein beta-microglobulin was characterized by affinity capillary electrophoresis (CE). CE could separate conformational variants of beta2-microglobulin and with the amyloid-specific dye Congo red as a buffer additive it was possible to measure different Congo red-affinities of native and abnormally folded beta2-microglobulin. We find that native beta2-microglobulin has an intermediate affinity for Congo red at pH 7.3 and that binding involves electrostatic interactions. The conformational variant of beta2-microglobulin that appears in acetonitrile solutions binds Congo red more strongly. Affinity CE using Congo red as a buffer additive is a new, simple, fast, and quantitative micromethod for the characterization of soluble conformational intermediates of amyloidogenic proteins.
Heegaard
N H
NH
Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark. nhe@ssi.dk
Sen
J W
JW
Nissen
M H
MH
D004396:Coloring Agents; D003224:Congo Red / Q000378:metabolism*; D019075:Electrophoresis, Capillary / Q000379:methods*; D013058:Mass Spectrometry; D011487:Protein Conformation; D001613:beta 2-Microglobulin / Q000737:chemistry / Q000378:metabolism*
D004396:Coloring Agents; D001613:beta 2-Microglobulin; D003224:Congo Red