CANINE HAPTOGLOBIN - UNIQUE HAPTOGLOBIN SUBUNIT ARRANGEMENT

1. 1. Isolated canine haptoglobin behaved identically to the α2β2 structure typical of human haptoglobin type 1-1 on alkaline polyacrylamide gel electrophoresis and on gel filtration. 2. 2. In the presence of urea or sodium dodecyl sulphate canine haptoglobin dissociated into αβ subunits that separated into α and β chains after reduction with 2-mercaptoethanol. 3. 3. Compositional analysis identified one less half-cystine in canine α chain when compared to human α1 chain. 4. 4. These results provide evidence that there is no inter α chain disulphide in canine haptoglobin comparable to the α120-α120 disulphide in human haptoglobin that links the two αβ subunits. © 1979.