Properties of a Serologically Active Substance from Leptospira icterohemorrhagiae (Wijnberg)

Abstract

Summary

Suspensions of viable cells of Leptospira icterohetnorrhagiae (Wijnberg) were disrupted with an equal volume of a solution containing 0.1 M NaCl, 0.2 M sodium citrate, and 0.4% sodium desoxycholate. An immunologically- reactive, non-dialyzable substance (Fraction 1) was prepared by a procedure which avoided heating and use of alkalis and acids. The active principle was isolated in mixture with a non-dialyzable polynucleotide moiety. The organism of L. icterohemorrhagiae contained an appreciable amount of the polynucleotide substance and was composed of pentose—as well as desoxy-pentosenucleic acids. Crystalline ribo- and desoxyribonuclease altered the absorption spectrum of the nucleotide, but failed to inactivate the antigen. On the basis of the latter evidence it appeared likely that the polynucleotide was not the determinant of immunological reactivity. The active principle resisted the action of trypsin, hemi-cellulase and was not destroyed by heating for 1 hour at 100°C.