It is composed of 5 polypeptide subunits without glycosylation with the same structure. It is composed of 187 amino acids. Under electron microscope, it is a ring symmetrical pentahedron, which crystallizes into a diamond, insoluble in water and heat resistant,
It is composed of five polypeptide subunits with the same structure and no glycosylation, which consists of 187 amino acids. It is a ring-symmetric pentahedron under the electron microscope, and its crystal is diamond-shaped, insoluble in water and heat-resistant.