Proteolytic degradation of the RGD-binding and non-RGD-binding conformers of human platelet integrin glycoprotein IIb/IIIa; clues for identification of regions involved in the receptor’'s activation - Calvete, JJ; Mann, K; Schafer, W; Femandez-Lafuente, R; Guisan, JM (Biochem J, 1994)