We have isolated from Bordetella pertussis an
oligopeptide with characteristic
amino acid composition. This
peptide was applied to mice in standardized tests for
pertussis immunization. In three tests with three independent isolates of
peptide, a significant and dose dependent protection was observed. One microgram of
peptide per mouse produces the same protective effect as 0.1 IU of
pertussis vaccine. It is important to note that similar
peptides can be isolated from other bacteria and other
DNA containing cellular organisms which have specific
amino acid compositions and which are
antigens specific for the organism from which they were isolated. The
antigens are very potent, e.g., one ng of Mycobacterium tuberculosis
peptide is equivalent to one unit of
tuberculin. It is conceivable that immunizing effects such as those observed for
pertussis are common to the
peptides of this group. Since all such
peptides are isolated from a group of low molecular weight
ribonucleoproteins, as first reported by WILHELM, we propose the term nucleopeptides for this group.
Oligopeptides of the nucleopeptide group are now available for sequence analysis. We expect that synthetic
peptides of this group will become available in time for diagnosis, prophylaxis and
therapy of a number of diseases.