Studies on an Antibacterial Polypeptide Extracted from Normal Tissues

Abstract

Continuation of previous studies with antibacterial polypeptides isolated from normal tissues reveal that the fraction from thyroid agglutinates several types of washed bacterial cells, Escherichia coli, Staphylococcus aureus and beta-hemolytic streptococci. The bacteria-polypeptide combination has been shown to be resistant to washing and to be capable of combining with ribonucleic acid. The results of these interactions on the O2 uptake of the bacteria as studied by the Warburg method revealed that the basic polypeptide once combined with the cell interferes with O2 uptake. This effect is not reversed by ribonucleic acid. However, the effect on O2 uptake is prevented if the nucleic acid is combined with the basic polypeptide before addition to the bacterial cells.