Vm. Dhople et R. Nagaraj, DELTA-TOXIN, UNLIKE MELITTIN, HAS ONLY HEMOLYTIC-ACTIVITY AND NO ANTIMICROBIAL ACTIVITY - RATIONALIZATION OF THIS SPECIFIC BIOLOGICAL-ACTIVITY, Bioscience reports, 13(4), 1993, pp. 245-250
The antimicrobial activity of a synthetic peptide corresponding to del
ta-hemolysin had been examined. The peptide did not exhibit antimicrob
ial activity against gram negative and gram positive micro-organisms u
nlike other hemolytic peptides like melittin. This lack of antibacteri
al activity arises due to the inability of delta-hemolysin to perturb
the negatively charged bacterial cell surface and permeabilize the bac
terial plasma membrane. However, the red blood cell surface has a stru
cture considerably different from bacteria and does not act as a barri
er to molecules reaching the lipid membrane. Hence delta-toxin can lys
e erythrocytes. Thus, the specificity in biological activity has been
rationalized in terms of differences in the interaction of the toxin w
ith the bacterial and red blood cell surfaces.