Electrophoresis, Vol.26, No.21, 4055-4063, 2005
Search of ligands for the amyloidogenic protein B-2-microglobulin by capillary electrophoresis and other techniques
beta(2)-Microglobulin (N-M) is a small amyloidogenic protein normally present on the surface of most nucleated cells and responsible for dialysis-related amyloidosis, which represents a severe complication of long-term hemodialysis. A therapeutic approach for this amyloidosis could be based on the stabilization of beta(2)-M through the binding to a small molecule, and consequent inhibition of protein misfolding and amyloid fibril formation. A few compounds have been described to weakly bind beta(2)-M, including the drug suramin. The lack of a binding site for nonpolypeptidic ligands on the beta(2)-M structure makes it difficult for both the identification of functional groups responsible for the binding and the search of hits to be optimized. The characterization of the binding properties of suramin for beta(2)-m by using three different techniques (surface plasmon resonance, affinity CE (ACE), ultrafiltration) is here described and the results obtained are compared. The common features of the chemical structures of the compounds known to bind the protein led us to select 200 sulfonated/suramin-like molecules from a wider chemical library on the basis of similarity rules, so as to possibly single out some interesting hits and to gain more information on the functional groups involved in the binding. The development of screening methods to test the compounds by using ultrafiltration and ACE is described.