The amino acid composition of tobacco mosaic virus protein

Abstract

The first complete analysis of the tobacco mosaic virus protein after it has been freed from nucleic acid is reported. Analyses after 24 and 48 hours of hydrolysis indicate marked decomposition of serine and threonine during hydrolysis and the values for these amino acids in the protein have been obtained by extrapolation to zero time. The corrected analytical values yield integral numbers for most of the amino acids and account for almost all the weight of the protein. The analyses indicate a minimal peptide chain molecular weight of 18,270 composed of the following 164 amino acid residues: Asp₁₉ Glu₁₇ Pro₈ Ser₁₈ Thr₁₇ Gly₆ Ala₁₅ Val₁₄ Leu₁₃ Isol₉ Tyr₄ Trypt₂ Phe₈ CySH₁ Lys₂ Arg₁₁ (-CONH₂)₂₀. From the above composition the calculated value for the partial specific volume (V̅) of the protein is 0.731.