Multimeric structure of expressed canine and human VWF proteins. (A) The multimeric structure of expressed VWF constructs was analyzed nonreduced on a 3% agarose–SDS gel. All samples were run on the same gel, and interfering (nonrelevant) lanes have been removed for clarity. No VWF was detected in the mock-transfected control (lane 7). Wild-type canine and human full-length VWF (lanes 2, 3) and normal human and canine plasmas (lanes 1 and 6) were normally multimerized. Neither Y87S-VWF (lane 4) nor Δpro (propeptide-deleted VWF, lane 5) formed high molecular weight multimers. (B) The structure of lower molecular weight VWF subunits was analyzed on a 3% MetaPhor-agarose submarine gel. No VWF was detected in the mock-transfected control (lane 2). Y87S-VWF and Δpro formed only a dimeric VWF species (lanes 4, 5). The density of the dimer and tetramer bands observed in human and canine VWF (lanes 1, 3) were calculated after scanning the immunoblot (peak 1 = dimer).