TY - JOUR

T1 - Peptide-membrane binding is not enough to explain bioactivity: A case study

AU - Syryamina, Victoria N.

AU - Afanasyeva, Ekaterina F.

AU - Dzuba, Sergei A.

AU - Formaggio, Fernando

AU - De Zotti, Marta

N1 - Funding Information: VNS is thankful to Russian Science Foundation (project #21-73-00011) for financial support. MDZ and FF are grateful to the Italian Ministry of Research (PRIN Prot. 2020833Y75 and Prot. 20173LBZM2), to the University of Padova (Italy) (grant number: P-DiSC#04BIRD2019-UNIPD ) and to the Italian Ministry for the Economic Development, MISE (grant number: PoC@Unipd - CUP 96I20000120004 . Project: ECOPEP) for supporting this research. Publisher Copyright: © 2022

PY - 2022/9/1

Y1 - 2022/9/1

N2 - Membrane-active peptides are a promising class of antimicrobial and anticancer therapeutics. For this reason, their molecular mechanisms of action are currently actively investigated. By exploiting Electron Paramagnetic Resonance, we study the membrane interaction of two spin-labeled analogs of the antimicrobial and cytotoxic peptide trichogin GA IV (Tri), with opposite bioactivity: Tri(Api8), able to selectively kill cancer cells, and Tri(Leu4), which is completely nontoxic. In our attempt to determine the molecular basis of their different biological activity, we investigate peptide impact on the lateral organization of lipid membranes, peptide localization and oligomerization, in the zwitter-ionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) model membrane We show that, despite their divergent bioactivity, both peptide analogs (i) are membrane-bound, (ii) display a weak tendency to oligomerization, and (iii) do not induce significant lipid rearrangement. Conversely, literature data show that the parent peptide trichogin, which is cytotoxic without any selectivity, is strongly prone to dimerization and affects the reorganization of POPC membranes. Its dimers are involved in the rotation around the peptide helix, as observed at cryogenic temperatures in the millisecond timescale. Since this latter behavior is not observed for the inactive Tri(Leu4), we propose that for short-length peptides as trichogin oligomerization and molecular motions are crucial for bioactivity, and membrane binding alone is not enough to predict or explain it. We envisage that small changes in the peptide sequence that affect only their ability to oligomerize, or their molecular motions inside the membrane, can tune the peptide activity on membranes of different compositions.

AB - Membrane-active peptides are a promising class of antimicrobial and anticancer therapeutics. For this reason, their molecular mechanisms of action are currently actively investigated. By exploiting Electron Paramagnetic Resonance, we study the membrane interaction of two spin-labeled analogs of the antimicrobial and cytotoxic peptide trichogin GA IV (Tri), with opposite bioactivity: Tri(Api8), able to selectively kill cancer cells, and Tri(Leu4), which is completely nontoxic. In our attempt to determine the molecular basis of their different biological activity, we investigate peptide impact on the lateral organization of lipid membranes, peptide localization and oligomerization, in the zwitter-ionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) model membrane We show that, despite their divergent bioactivity, both peptide analogs (i) are membrane-bound, (ii) display a weak tendency to oligomerization, and (iii) do not induce significant lipid rearrangement. Conversely, literature data show that the parent peptide trichogin, which is cytotoxic without any selectivity, is strongly prone to dimerization and affects the reorganization of POPC membranes. Its dimers are involved in the rotation around the peptide helix, as observed at cryogenic temperatures in the millisecond timescale. Since this latter behavior is not observed for the inactive Tri(Leu4), we propose that for short-length peptides as trichogin oligomerization and molecular motions are crucial for bioactivity, and membrane binding alone is not enough to predict or explain it. We envisage that small changes in the peptide sequence that affect only their ability to oligomerize, or their molecular motions inside the membrane, can tune the peptide activity on membranes of different compositions.

KW - Bioactivity

KW - EPR/ESR

KW - Lateral lipid organization

KW - Membrane-active peptides

KW - Trichogin

KW - Amino Acid Sequence

KW - Lipid Bilayers/chemistry

KW - Electron Spin Resonance Spectroscopy

KW - Membranes/metabolism

KW - Spin Labels

KW - Anti-Bacterial Agents/pharmacology

UR - http://www.scopus.com/inward/record.url?scp=85131396993&partnerID=8YFLogxK

U2 - 10.1016/j.bbamem.2022.183978

DO - 10.1016/j.bbamem.2022.183978

M3 - Article

C2 - 35659865

AN - SCOPUS:85131396993

VL - 1864

JO - Biochimica et Biophysica Acta - Biomembranes

JF - Biochimica et Biophysica Acta - Biomembranes

SN - 0005-2736

IS - 9

M1 - 183978

ER -