약독 담배모자이크바이러스 II. RNA 및 외피단백질의 특성

Studies on Mild Mutants of Tobacco Mosaic Virus II. Biochemical Properties of Ribonucleic Acid and Coat Protein

액독 TMV, Tw 333 RNA 및 외피단백질에 대한 생화학적 특성을 조사하였다. Tw333-RNA는 $2.03\times10^6$dalton의 분자량을 나타냈고, 고기조성은 guanine 25.4, adenine 29.2, cytosine 17.5, uracil 27.9mol이었다. 열처리에서 얻어진 이 RNA의 농색효과는 $25.1\%$를 나타냈고, 이때 Tm치는 $47^{\circ}C$였다. 한편 Tw 333의 외피단백질은 17,500 dalton의 분자량을 보였으며, 16종의 아미노산으로 구성된 158개의 아미노산잔기를 나타냈다. Trypsin으로 분해한 단백질은 9종의 ninhydrin 양성반응 peptide를 형성하였다. 이들 약독 TMV, Tw333-RNA 및 외피단백질의 생화학적 특성은 원주 OM계통과 전반적으로 매우 유사하였다. 그러나 고기조성, 농색효과, 아미노산조성 및 peptide map에서 약간의 차가 인정되었다.

The biochemical properties of ribonucleic acid (RNA) and coat protein of the mild tobacco mosaic virus (TMV) mutant, Tw 333 are described. The molecular weight of the RNA calculated from polyacrylamide gel electrophoresis was $2.03\times10^6$ daltons. The molar ratio of the bases of the RNA was 25.4 guanine, 29.2 adenine, 17.5 cytosine and 27.9 uracil in moles. The hyperchromicity on Tw 333-RNA by thermal denaturation was $25.1\%$, indicating Tm value of $47^{\circ}C$. The virus coat protein migrated as a single component in SDS-polyacrylamide gel electrophoresis and had a molecular weight of 17,500 daltons. A total of 158 amino acid residues are present in the protein. Separation of the tryptic peptides by electrophoresis and chromatography yielded ninhydrin-positive compounds. The biochemical properties of RNA and coat protein of the mild mutant we very similar to those of wild type of TMV-OM strain, but some difference between the strains were observe in the base composition, hyperchromicity, amino acid composition and tryptic peptide map.