Structure of a synthetic fragment of the LALF protein when bound to lipopolysaccharide.
Peptidic lipopolysaccharide (LPS) antagonists are the subject of intensive research. We report an NMR and modeling study of LALF-14 (GCKPTFRRLKWKYKCG), a synthetic cyclized fragment of the limulus anti-LPS factor (LALF) comprising residues 36-47. In a mixture with LPS we observed the transferred NOE effect and derived the LPS-bound structure of LALF-14. Neither the free nor the LPS-bound peptide displays NOEs indicative of a beta-sheet-like structure that is adopted by the fragment in the full-size protein. However, docking calculations show that the former structure is not a prerequisite for binding of LALF-14 to LPS.
Pristovsek
Primoz
P
Laboratory of Biotechnology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia. primoz.pristovsek@ki.si
Fehér
Krisztina
K
Szilágyi
László
L
Kidric
Jurka
J
D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D007447:Invertebrate Hormones / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry*; D011485:Protein Binding; D012996:Solutions; D014867:Water
D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D007447:Invertebrate Hormones; C499147:LALF-14 peptide; D008070:Lipopolysaccharides; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D012996:Solutions; C034705:antilipopolysaccharide factor (Limulus); D014867:Water