2IGR

Solution structure of CB1a, a novel anticancer peptide derived from natural antimicrobial peptide cecropin B


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure and function of a custom anticancer peptide, CB1a

Wu, J.-M.Jan, P.-S.Yu, H.-C.Haung, H.-Y.Fang, H.-J.Chang, Y.-I.Cheng, J.-W.Chen, H.M.

(2009) Peptides 30: 839-848

  • DOI: https://doi.org/10.1016/j.peptides.2009.02.004
  • Primary Citation of Related Structures:  
    2IGR

  • PubMed Abstract: 

    Several natural antimicrobial peptides including cecropins, magainins and melittins have been found to kill cancer cells. However, their efficacy may not be adequate for their development as anticancer agents. In this study, we used a natural antimicrobial peptide, cecropin B (CB), as a template to generate a novel anticancer peptide. Cecropin B is an amphipathic and polycationic peptide derived from the hemolymph of Hyalophora cecropia with well-known antimicrobial and cytolytic properties. The signature pattern of cecropins is W-x-(0,2)-[KDN]-x-{L}-K-[KRE]-[LI]-E-[RKN] (PROSITE: PS00268), and this signature sequence is located at N-terminus of CB. CB1a was constructed by repeating the N-terminal ten amino acids of CB three times and including a hinge near C-terminus. The circular dichroism spectra showed that CB1a is unstructured in aqueous solution, but adopt a helical conformation in membrane-like environment. The solution structure of CB1a in a polar solvent was also studied by NMR. CB1a formed a helix-hinge-helix in 20% HFIP solution, and it was found the bent angle between two helical segments was induced ranging from 60 degrees to 110 degrees . A heparin-binding motif is located in the central part of helix 1. Isothermal titration calorimetry reveals the association constant of CB1a bound to low molecular weight heparin is 1.66 x 10(5)M(-1) at physiological ionic strength at 25 degrees C. Binding of CB1a to heparin produces a large conformational change toward a more structural state. CB1a demonstrated promising activity against several cancer cells but low toxicity against non-cancer cells. The IC(50) of CB1a on leukemia and stomach carcinoma cells were in the range of 2-8-fold lower than those of CB. Besides, CB1a exhibited low hemolytic activity against human red blood cells. Due to these properties, CB1a has the potential to become a promising anticancer agent.


  • Organizational Affiliation

    Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Anticancer peptide CB1a34Hyalophora cecropiaMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

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Entry History 

Deposition Data

  • Released Date: 2006-11-18 
  • Deposition Author(s): Wu, J.-M.

Revision History  (Full details and data files)

  • Version 1.0: 2006-11-18
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance