Solution Structure of the acyclic permutant des-(24-28)-kalata B1.

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Linearization of a naturally occurring circular protein maintains structure but eliminates hemolytic activity

Barry, D.G.Daly, N.L.Clark, R.J.Sando, L.Craik, D.J.

(2003) Biochemistry 42: 6688-6695

  • DOI: https://doi.org/10.1021/bi027323n
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Cyclotides are a recently discovered family of disulfide rich proteins from plants that contain a circular protein backbone. They are exceptionally stable, as exemplified by their use in native medicine of the prototypic cyclotide kalata B1. The peptide retains uterotonic activity after the plant from which it is derived is boiled to make a medicinal tea. The circular backbone is thought to be in part responsible for the stability of the cyclotides, and to investigate its role in determining structure and biological activity, an acyclic derivative, des-(24-28)-kalata B1, was chemically synthesized and purified. This derivative has five residues removed from the 29-amino acid circular backbone of kalata B1 in a loop region corresponding to a processing site in the biosynthetic precursor protein. Two-dimensional NMR spectra of the peptide were recorded, assigned, and used to identify a series of distance, angle, and hydrogen bonding restraints. These were in turn used to determine a representative family of solution structures. Of particular interest was a determination of the structural similarities and differences between des-(24-28)-kalata B1 and native kalata B1. Although the overall three-dimensional fold remains very similar to that of the native circular protein, removal of residues 24-28 of kalata B1 causes disruption of some structural features that are important to the overall stability. Furthermore, loss of hemolytic activity is associated with backbone truncation and linearization.

  • Organizational Affiliation

    Institute for Molecular Bioscience, Australian Research Council Special Research Centre for Functional and Applied Genomics, University of Queensland, Brisbane 4072, Australia.


Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
kalata B124N/AMutation(s): 0 
Find proteins for P56254 (Oldenlandia affinis)
Explore P56254 
Go to UniProtKB:  P56254
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP56254
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-06-24
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-23
    Changes: Data collection, Database references, Derived calculations