A study of the self-assembly process in a small spherical virus formation of organized structures from protein subunits in vitro

• Published in: Virology (New York, N.Y.) Vol. 31; no. 2; pp. 354 - 379
• Main Authors: Bancroft, J.B., Hills, G.J., Markham, Rou
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.1967
• Subjects: Biometry; Hydrogen-Ion Concentration; Microscopy, Electron; Models, Theoretical; Plant Viruses - drug effects; Plant Viruses - growth & development; Ribonucleases - pharmacology
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/0042-6822(67)90180-8

The arrangement of the morphological units of cowpea chlorotic mottle virus (CCMV), which has a dry diameter of 250 A, is consistent with that expected for a 32-unit structure, the units being situated on the vertices of a rhombic triacontahedron. The hydrodynamic behaviour of CCMV is pH dependent. The particles “swell” near neutrality and in doing so become susceptible to attack by nucleases. After treatment with pancreatic ribonuclease, ellipsoidal particles of 210 A diameter and 280 A length, small icosahedral particles of 160 A diameter, double-shelled particles of 340 A, and long tubes with a diameter of 160 A and rounded ends are produced. All these particles are also found after treatment with takadiesterase T 1 and in addition, small spherical particles with a double shell with an outer diameter of 250 A, and tubes with a diameter of 250 A which may enclose 160 A tubes, are produced. The production of these new forms are described and discussed and the products are related to model structures. In addition, a possible reconstitution system for CCMV and brome mosaic virus is outlined.