1956 Volume 9 Issue 4-5 Pages 179-189
The fact that proteins having definite tuberculin activity are obtainable not only from the culture filtrate, but also from the bacterial cells of tubercle bacilli, has already been reported by a number of workers; among them, Heidelberger and Menzel (1934), Gronwall (1944), Heckly and Watson (1950), Baldwin et al. (1953), Seibert and Fabrizio (1952), and Ohtomo (1955) are included. Throughout these reports—in the opinion of the respective authors—the following points are the most conspicuous features of the bacillary protein: the high degree of purity and high potency (Seibert and Fabrizio, 1952) ; the remarkable ability in sensitizing animals (Baldwin et al., 1953) ; and the considerable amount of transfer of the protein from the bacterial cells into the culture filtrate when the entire culture was heated (Ohtomo, 1955) .
A discussion in the qualitative differences between the proteins of the culture filtrate and of the bacterial cells would pose the following problem: whether the protein present in the culture filtrate is merely the degradation product of the bacterial cells; or whether, in addition, it contains a secretory type of protein discharged from the bacterial cells themselves. If the former is the case, the protein of the culture filtrate and that of the bacterial cells should be the same in nature; and hence, on preparation of tuberculin protein, the extraction of bacterial cells would provide the best method as it would reserve the high potency and high purity (Seibert and Fabrizio, 1952) . But if the latter is the case, the protein obtained from the two sources should not be the same; and hence these sources would have to be differentiated, not only out of biological interest, but also from the practical standpoint of the preparation of the tuberculin protein—especially when the increasing demand for adopting the use of PPD in routine work in this country is taken into consideration.
Since there has appeared in a previous paper (Kasuya et al., 1956) a successful method for obtaining more detailed information on the chemical characteristics of tuberculin proteins obtained from culture filtrate, with respect to the nature of their constituent peptides, by the use of DNP-technique and countercurrent distribution, the task of the present author, in the light of this new method, has become one of elucidating the peptide constitution of the protein obtained from the bacterial cells of the human strains Aoyama-B and Frankfurt.
