Abstract
Twenty peptides of tobacco mosaic virus protein covering the whole amino acid sequence of the polypeptide chain have been tested for their capacity to inhibit the quantitative precipitation of tobacco mosaic virus with the specific antibodies. Only four amino acid sequences, representing 15-20% of the polypeptide chain, have been found to diminish quantitative precipitation of TMV with anti TMV serum. Lack of additivity of the individual inhibition values gives evidence that the specific antibodies are not directed against isolated amino acid sequences.