Journal Article

Structural basis for endotoxin neutralisation and anti-inflammatory activity of thrombin-derived C-terminal peptides

Saravanan, Rathi, Choong, Yeu Khai, Singh, Shalini, Malmsten, Martin, Bond, Peter J, Schmidtchen, Artur, Holdbrook, Daniel A, Berglund, Nils A, Kjellström, Sven, Petrlova, Jitka

2018

Overview

Thrombin-derived C-terminal peptides (TCPs) of about 2 kDa are present in wounds, where they exert anti-endotoxic functions. Employing a combination of nuclear magnetic resonance spectroscopy (NMR), biophysical, mass spectrometry and cellular studies combined with in silico multiscale modelling, we here determine the bound conformation of HVF18 (HVFRLKKWIQKVIDQFGE), a TCP generated by neutrophil elastase, in complex with bacterial lipopolysaccharide (LPS) and define a previously undisclosed interaction between TCPs and human CD14. Further, we show that TCPs bind to the LPS-binding hydrophobic pocket of CD14 and identify the peptide region crucial for TCP interaction with LPS and CD14. Taken together, our results demonstrate the role of structural transitions in LPS complex formation and CD14 interaction, providing a molecular explanation for the previously observed therapeutic effects of TCPs in experimental models of bacterial sepsis and endotoxin shock. Thrombin-derived C-terminal peptides (TCPs) have anti-endotoxic functions in wounds by binding to bacterial lipopolysaccharide (LPS) and Gram-negative bacteria. Here authors use a spectrum of biophysical techniques to determine the conformation of a TCP in complex with LPS and define the interaction between TCPs and CD14.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 101/58 / 101/6 / 631/114 / 631/250/256 / 631/250/262 / 631/57 / 631/57/2272 / Amino Acid Sequence / Anti-inflammatory agents / Antimicrobial Cationic Peptides - chemistry / Antimicrobial Cationic Peptides - immunology / Antimicrobial Cationic Peptides - metabolism / Bacteria / Binding / Binding Sites / Biofysik / Biophysics / CD14 antigen / Complex formation / Conformation / Elastase / Endotoxin shock / Endotoxins / Escherichia coli - genetics / Escherichia coli - metabolism / Fysik / Gram-negative bacteria / Humanities and Social Sciences / Humans / Hydrophobic and Hydrophilic Interactions / Hydrophobicity / Inflammation / Leukocyte Elastase - chemistry / Leukocyte Elastase - immunology / Leukocytes (neutrophilic) / Lipopolysaccharide Receptors - chemistry / Lipopolysaccharide Receptors - immunology / Lipopolysaccharide Receptors - metabolism / Lipopolysaccharides / Lipopolysaccharides - chemistry / Lipopolysaccharides - immunology / Lipopolysaccharides - metabolism / Magnetic resonance spectroscopy / Mass spectrometry / Mass spectroscopy / Molecular chains / Molecular modelling / multidisciplinary / Natural Sciences / Naturvetenskap / Neutralization Tests / NMR / NMR spectroscopy / Nuclear magnetic resonance / Peptides / Physical Sciences / Protein Binding / Protein Conformation, alpha-Helical / Protein Conformation, beta-Strand / Protein Interaction Domains and Motifs / Science / Science (multidisciplinary) / Sepsis / THP-1 Cells / Thrombin / Thrombin - chemistry / Thrombin - immunology / Thrombin - metabolism / Wounds