【摘要】 本文对棉铃虫质型多角体病毒中国江苏分离株的生物物理和生物化学特性进行了研究,棉铃虫CPV通过其寄主幼虫大量增殖,经蔗糖梯度超离心纯化,CPV粒子由碱液溶解多角体释出,其沉降系数为403.9S,分子量为41.9×10~6,CPV多角体蛋白的主要组份为一种,分子量为27,000;CPV粒子结构蛋白则由六种多肽组成,经聚丙烯酰胺凝胶等电聚焦电泳,CPV多角体蛋白和CPV粒子均包含10种以上的多肽组份,经双向电泳,(PV粒子结构蛋白包含15种以上的多肽组份,CPV多角体蛋白氨基酸组成中不含半胱氨酸,其碱性氨基酸与酸性氨基酸比值为1.005,用SDS-热酚法提取所得CPV核酸,其解链温度为83侧;其碱基组成,A=U,G=C,说明CPV核酸是双链RNA,其G+C％为43％,在1％琼脂糖凝胶和3％聚丙烯酰胺凝胶中电泳,CPV RNA分别可分得11和13条基因片段,各片段大小为0.51～2.45×10~6,总分子量为17.94×10~6,电镜研究显示了CPV RNA在0.3μ,0.6μ1.0μ处有3个分布峰。更多还原

【Abstract】 A cytoplasmic polyhedrosis virus (CPV) from the cotton bollworm, Heliothis armigera (Hubn.), was characterized biophysically and biochemically. The virus was reproduced in its host larva and purified by sucrose-gradient centrifugation. The virions after releasing from the polyhedra had a sedimentation coefficient of 403.9S, and a molecular mass of 41.9 M dal-tons. The polyhedrin had a molecular mass of 27 K daltons. Six virus poly-peptides ranging in size from 28.5 to 120 K daltons were detected after separation by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophor-esis. More than 10 polypeptides were found both in the polyhedrin and in the virions by isoelectric focusing. More than 15 viral structural proteins were detected by two-dimensional electrophoresis. No cysteine was found in the polyhedrin in amino acid analysis, and the ratio of basic amino acids to acidic amino acids was 1.005. The CPV genome was double-strandedRNA with G + C content of 43% and a Tm of 83℃. The genome consistedof eleven (in 1% agarose gel electrophoresis) or of thirteen (in 3% polyacryl-amide gel electrophoresis) RNA segments. Their molecular mass ranged from 0.51 to 2.45 M daltons with a total of 17.94 M daltons. Three distribution peaks of the RNA segments contour length were found at 0.3μ, 0.6μ, and 1.0μ, respectively, by electron microscopy.更多还原