Insights into membrane translocation of protegrin antimicrobial peptides by multistep molecular dynamics simulations

Pin Kuang Lai, Yiannis N. Kaznessis

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 Scopus citations

Abstract

Protegrin-1 (PG-1) is a cationic arginine-rich antimicrobial peptide. It is widely accepted that PG-1 induces membrane disruption by forming pores that lead to cell death. However, the insertion mechanism for these highly cationic peptides into the hydrophobic membrane environment is still poorly understood at the molecular scale. It has previously been determined that the association of arginine guanidinium and lipid phosphate groups results in strong bidentate bonds that stabilize peptide-lipid complexes. It has also been suggested that arginine residues are able to drag phosphate groups as they insert inside the membrane to form a toroidal pore. However, whether bidentate bonds play a significant role in inducing a pore formation remains unclear. To investigate the role of bidentate complexes in PG-1 translocation, we conducted molecular dynamics simulations. Two computational electroporation methods were implemented to examine the translocation process. We found that PG-1 could insert into the membrane, provided the external electric potential is large enough to first induce a water column or a pore within the lipid bilayer membrane. We also found that the highly charged PG-1 is capable in itself of inducing molecular electroporation. Substitution of arginines with charge-equivalent lysines showed a markedly reduced tendency for insertion. This indicates that the guanidinium group likely facilitates PG-1 translocation. Potential of mean force calculations suggests that peptide insertion inside the hydrophobic environment of the membrane core is not favored. We found that formation of a water column or a pore might be a prerequisite for PG-1 translocation. We also found that PG-1 can stabilize the pore after insertion. We suggest that PG-1 could be a pore inducer and stabilizer. This work sheds some light on PG-1 translocation mechanisms at the molecular level. Methods presented in this study may be extended to other arginine-rich antimicrobial and cell-penetrating peptides.

Original languageEnglish
Title of host publication2020 Virtual AIChE Annual Meeting
Pages6056-6065
Number of pages10
ISBN (Electronic)9780816911141
DOIs
StatePublished - 2020
Event2020 AIChE Annual Meeting - Virtual, Online
Duration: 16 Nov 202020 Nov 2020

Publication series

NameAIChE Annual Meeting, Conference Proceedings
Volume2020-November

Conference

Conference2020 AIChE Annual Meeting
CityVirtual, Online
Period16/11/2020/11/20

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