The worrisome emergence of pathogens resistant to conventional
drugs has stimulated the search for new classes of antimicrobial and
antiparasitic agents from natural sources.
Antimicrobial peptides (AMPs), acting through mechanisms that do not rely on the interaction with a specific receptor, provide new possibilities for the development of
drugs against resistant organisms. This study sought to purify and proteomically characterize the antimicrobial and
antiparasitic peptidomes of B. atrox and B. jararacussu
snake venoms against Gram-positive (
Staphylococcus aureus,
Methicillin-resistant Staphylococcus aureus—
MRSA), Gram-negative (
Escherichia coli,
Pseudomonas aeruginosa,
Klebsiella pneumoniae)
bacteria, and the protozoan
parasites Leishmania amazonensis and
Plasmodium falciparum (
clone W2, resistant to
chloroquine). To this end, B. atrox and B. jararacussu
venom peptides were purified by combination of 3 kDa cut-off Amicon® ultracentrifugal
filters and reverse-phase
high-performance liquid chromatography, and then identified by electrospray-ionization Ion-Trap/
Time-of-Flight
mass spectrometry. Fourteen distinct
peptides, with masses ranging from 443.17 to 1383.73 Da and primary structure between 3 and 13
amino acid residues, were sequenced. Among them, 13 contained unique sequences, including 4 novel
bradykinin-potentiating-like
peptides (BPPs), and a
snake venom metalloproteinase tripeptide inhibitor (SVMPi). Although commonly found in
Viperidae venoms, except for Bax-12, the BPPs and SVMPi here reported had not been described in B. atrox and B. jararacussu
venoms. Among the novel
peptides, some exhibited bactericidal activity towards P. aeruginosa and S. aureus, had low hemolytic effect, and were devoid of
antiparasitic activity. The identified novel
antimicrobial peptides may be relevant in the development of
new drugs for the management of multidrug-resistant Gram-negative and
Gram-positive bacteria.