The solution structure of the active domain of CAP18--a lipopolysaccharide binding protein from rabbit leukocytes.
We have employed the circular dichroism (CD) technique to characterize the solution structure of CAP18(106-137), a lipopolysaccharide (LPS) binding, antimicrobial protein, and its interaction with lipid A. Our results revealed that CAP18(106-137) may exist in at least three lipid A concentration-dependent, primarily helix conformations. The 'model' structure of CAP18(106-137) in 30% (v/v) TFE, determined by nuclear magnetic resonance (NMR) technique, was found to be a complete and very rigid helix. In this conformation, the cationic and hydrophobic groups of CAP18(106-137) are separated into patches and stripes in such a way that it can favorably interact with lipid A through either coulombic interaction with the diphosphoryl groups or hydrophobic interaction with the fatty acyl chains.
Chen
C
C
Division of Structural Biology, Academia Sinica, Nankang, Taipei, Taiwan, ROC.
Brock
R
R
Luh
F
F
Chou
P J
PJ
Larrick
J W
JW
Huang
R F
RF
Huang
T H
TH
D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D054804:Cathelicidins; D002942:Circular Dichroism; D008050:Lipid A; D008070:Lipopolysaccharides / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation
D023181:Antimicrobial Cationic Peptides; D002352:Carrier Proteins; D054804:Cathelicidins; D008050:Lipid A; D008070:Lipopolysaccharides; D010446:Peptide Fragments