Biological Assembly 1  

 3D View: Structure

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 2.79 kDa 
• Atom Count: 197 
• Residue Count: 26 
• Unique protein chains: 1

2KJN

pH dependent structures of LAH4 in micellar environmnet:mode of acting

• DOI: 10.2210/pdb2KJN/pdb
• BMRB: 16332

• Classification: DE NOVO PROTEIN
• Organism(s): synthetic construct
• Mutation(s): No 


• Deposited: 2009-06-04 Released: 2010-06-23 
• Deposition Author(s): Georgescu, J., Bechinger, B.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 20 
• Conformers Submitted: 20 
• Selection Criteria: structures with the lowest energy 

Literature

NMR structures of the histidine-rich peptide LAH4 in micellar environments: membrane insertion, pH-dependent mode of antimicrobial action, and DNA transfection.

Georgescu, J., Munhoz, V.H., Bechinger, B.

(2010) Biophys J 99: 2507-2515

• PubMed: 20959091 
• DOI: 10.1016/j.bpj.2010.05.038
• Primary Citation of Related Structures:  
  2KJO, 2KJN


• PubMed Abstract: 
  

The LAH4 family of histidine-rich peptides exhibits potent antimicrobial and DNA transfection activities, both of which require interactions with cellular membranes. The bilayer association of the peptides has been shown to be strongly pH-dependent, with in-planar alignments under acidic conditions and transmembrane orientations when the histidines are discharged. Therefore, we investigated the pH- and temperature-dependent conformations of LAH4 in DPC micellar solutions and in a TFE/PBS solvent mixture. In the presence of detergent and at pH 4.1, LAH4 adopts helical conformations between residues 9 and 24 concomitantly with a high hydrophobic moment. At pH 6.1, a helix-loop-helix structure forms with a hinge encompassing residues His¹⁰-Ala¹³. The data suggest that the high density of histidine residues and the resulting electrostatic repulsion lead to both a decrease in the pK values of the histidines and a less stable α-helical conformation of this region. The hinged structure at pH 6.1 facilitates membrane anchoring and insertion. At pH 7.8, the histidines are uncharged and an extended helical conformation including residues 4-21 is again obtained. LAH4 thus exhibits a high degree of conformational plasticity. The structures provide a stroboscopic view of the conformational changes that occur during membrane insertion, and are discussed in the context of antimicrobial activity and DNA transfection.

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Organizational Affiliation: 

Institut de Chimie, Université de Strasbourg/Centre National de Recherche Scientifique, France.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
lah4	A	26	synthetic construct	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 20 
• Conformers Submitted: 20 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2KJN Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2009-06-04 
• Released Date: 2010-06-23 
Deposition Author(s): Georgescu, J., Bechinger, B.

Revision History 

• Version 1.0: 2010-06-23
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance