Fig. 3.
Binding of human platelet antigen (HPA)-2 antibodies to both forms of recombinant glycoprotein (GP)Ib measured by resonant mirror studies.
Addition of recombinant GPIbα to biosensor cuvette (1). Washing with TBS/Ca++ (2). Addition of serum diluted 1 in 10 (3). Washing with TBS/Ca++(4). Distance between points y1 and y2 represent specifically bound antibody remaining after TBS/Ca++ wash, expressed as arc seconds. (A) Incubation of anti-HPA-2a with Thr-145, y2 − y1 = 83 arc seconds. (B) Incubation of anti-HPA-2a with Met-145, y2 − y1 = 21 arc seconds. (C) Incubation of anti-HPA-2b with Thr-145, y2 − y1 = 7 arc seconds. (D) Incubation of anti-HPA-2b with Met-145, y2 − y1 = 128 arc seconds.
