Abstract: | The purified flacherie viruses of the silkworm, Bombyx mori, (FVS I, FVS II, FVS III, and FVS IV) were iodinated by using chloramine-T. The iodinated FVSes were purified by sucrose density gradient centrifugation or 2.4% polyacrylamide gel electrophoresis. FVS IV was found in the sedimentation analysis of FVS I, FVS II, and FVS IV. Electrophoretic patterns of FVS IV showed that it was a mixture of components having identical mobilities with FVS I, EVS IIa, and FVS IIb. FVS IV was a decomposed particle of FVS I, FVS II, and/or FVS III. All of these particles contained three polypeptides with molecular weights of about 51,000, 31,000, and 12,000 daltons. FVS I composed of six polypeptides with molecular weights of 67,000, 51,000, 39,000, 31,000, 14,000, and 12,000 daltons. The maturation process of FVS I was discussed and was suggested as the following process, FVS IIb→FVS IIa→FVS I. It is not clear whether FVS III is an intermediate for FVS IIa to convert into FVS I, or FVS III is a decomposed particle of FVS I. |