Physicochemical properties of tipula iridescent virus.

The molecular weight of Tipula iridescent virus, based on sedimentation and diffusion coefficients, was 5.51 x 10(8), with hydration of 0.57 g of water per g of virus. Deoxyribonucleic acid content, based on total inorganic phosphorus liberated, was 19 +/- 0.2%. At 260 mmu, the virus gave an uncorrected absorbance of 18.2 cm(2)/mg of virus and a light-scattering corrected absorbance of 9.8 cm(2)/mg of virus. Amino acid analyses of the virus protein revealed a remarkable similarity to Sericesthis iridescent virus. The possibility is discussed that the four iridescent insect viruses reported to date bear a strain relationship.