Purification of PaTx-II from the venom of Australian King Brown Snake and characterization of its antimicrobial and wound healing activities

Samy, R. P., Mackessy, S. P., Jeyasankar, A., Ponraj, M. R., Franco, O. L., Cooper, M. A., Kandasamy, M., Mohanta, T. K., Bhagavathsingh, J. and Vaiyapuri, S. ORCID: https://orcid.org/0000-0002-6006-6517 (2023) Purification of PaTx-II from the venom of Australian King Brown Snake and characterization of its antimicrobial and wound healing activities. International Journal of Molecular Sciences, 24 (5). 4359. ISSN 1422-0067 doi: 10.3390/ijms24054359

Abstract/Summary

Infections caused by multi-drug-resistant (MDR) bacteria are a global threat to human health. As venoms are the source of biochemically diverse bioactive proteins and peptides, we investigated the antimicrobial activity and murine skin infection model-based wound healing efficacy of a 13 kDa protein. The active component PaTx-II was isolated from the venom of Pseudechis australis (Australian King Brown or Mulga Snake). PaTx-II inhibited the growth of Gram-positive bacteria in vitro, with moderate potency (MICs of 25 µM) observed against S. aureus, E. aerogenes, and P. vulgaris. The antibiotic activity of PaTx-II was associated with disruption of membrane integrity, pore formation and lysis of bacterial cells, as evidenced by scanning and transmission micros-copy. However, these effects were not observed with mammalian cells, and PaTx-II exhibited minimal cytotoxicity (CC50 > 1000 µM) toward skin/lung cells. Antimicrobial efficacy was then determined using a murine model of S. aureus skin infection. Topical application of PaTx-II (0.5 mg/kg) cleared S. aureus with concomitant increased vascularization and re-epithelialization promoting wound healing. As small proteins and peptides can possess immunomodulatory ef-fects to enhance microbial clearance, cytokines and collagen from the wound tissue samples were analyzed by immunoblots and immunoassays. The amounts of type I collagen in PaTx-II treated sites were elevated compared to the vehicle controls, suggesting a potential role for collagen in fa-cilitating the maturation of the dermal matrix during wound healing. Levels of proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), cy-clooxygenase-2 (COX-2) and interleukin-10 (IL-10), factors known to promote neovasculariza-tion, were substantially reduced by PaTx-II treatment. Further studies that characterize the con-tributions towards efficacy imparted by in vitro antimicrobial and immunomodulatory activity with PaTx-II are warranted.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/110577
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Division of Pharmacology
Publisher	MDPI
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