Studies by Small‐Angle X‐Ray Scattering of the Quaternary Structure of the β‐Haemocyanin of Helix pomatia

Abstract

H. pomatia .beta.-hemocyanin was studied in solution by small-angle X-ray scattering. The molecular parameters determined were: MW = 9.02 .times. 106, volume = 14,000 nm3, radius of gyration = 18.4 nm, and radius of the spherical subunits = 2.5 .+-. 0.2 nm. With these data, and with information of dissociation products described previously, a model of the molecule was built whose theoretical scattering curve showed good agreement with the experimental one. The model consists of 160 spherical subunits of a radius of 2.5 nm; 12 rings each built up of 10 spheres form the outer wall of a hollow cylinder; 20 subunits are situated at the inner side of each end.