1G89

STRUCTURE OF THE BOVINE ANTIMICROBIAL PEPTIDE INDOLICIDIN BOUND TO DODECYLPHOSPHOCHOLINE MICELLES

Summary for 1G89

• Entry DOI: 10.2210/pdb1g89/pdb
• Related: 1G8C
• NMR Information: BMRB: 5938,5941
• Descriptor: INDOLICIDIN (1 entity in total)
• Functional Keywords: poly-l-proline ii helix, half turn, antimicrobial protein
• Total number of polymer chains: 1
• Total formula weight: 1908.30

Authors

Rozek, A.,Friedrich, C.L.,Hancock, R.E. (deposition date: 2000-11-16, release date: 2000-11-29, Last modification date: 2024-10-30)

Primary citation

Rozek, A.,Friedrich, C.L.,Hancock, R.E.
Structure of the bovine antimicrobial peptide indolicidin bound to dodecylphosphocholine and sodium dodecyl sulfate micelles.
Biochemistry, 39:15765-15774, 2000

PubMed Abstract: Indolicidin is a cationic, 13-residue antimicrobial peptide (ILPWKWPWWPWRR-NH(2)) which is unusually rich in tryptophan and proline. Its antimicrobial action involves the bacterial cytoplasmic membrane. Fluorescence and circular dichroism spectra demonstrated the structural similarity of indolicidin in complexes with large unilamellar phospolipid vesicles and with detergent micelles. The structure of indolicidin bound to zwitterionic dodecylphosphocholine (DPC) and anionic sodium dodecyl sulfate (SDS) micelles was determined using NMR methods and shown to represent a unique membrane-associated peptide structure. The backbone structure in DPC, well defined between residues 3 and 11, was extended, with two half-turns at residues Lys-5 and Trp-8. The backbone structure in SDS, well defined between residues 5 and 11, was also extended, but lacked the bend in the C-terminal half. Indolicidin in complexes with DPC had a central hydrophobic core composed of proline and tryptophan, which was bracketed by positively charged regions near the peptide termini. The tryptophan side chains, with one exception, folded flat against the peptide backbone, thus giving the molecule a wedge shape. Indolicidin in complexes with SDS had an arrangement of hydrophobic and cationic regions similar to that found in the presence of DPC. The tryptophan side chains were less well defined than for indolicidin in DPC and extended away from the peptide backbone. The preferred location of indolicidin in DPC micelles and lipid bilayers, analyzed using spin-label probes, was at the membrane interface.

PubMed: 11123901
DOI: 10.1021/bi000714m

Experimental method

SOLUTION NMR