Subunit association and heterogeneity of Limulus polyphemus hemocyanin

Abstract
The MW of the 6S, 24S, 36S and 60S components of L. polyphemus hemocyanin were determined by high speed sedimentation equilibrium to be 69,400, 856,000, 1,690,000 and 3,160,000. The behavior of this hemocyanin appears similar to that of other arthropod hemocyanins where the 1st aggregation step is the formation of a hexamer of the 6S monomer. Here the larger aggregated states (24S, 36S and 60S) are successive dimers of an unobserved hexamer (16S). The 24S-36S-60S association was heterogeneous, suggesting that 24S components of different composition may be present.