2MSQ | pdb_00002msq

Solution study of cBru9a

• PDB DOI: https://doi.org/10.2210/pdb2MSQ/pdb
• BMRB: 25129

• Classification: TOXIN
• Organism(s): synthetic construct
• Mutation(s): No 


• Deposited: 2014-08-05 Released: 2015-07-22 
• Deposition Author(s): Akcan, M., Clark, R.J., Daly, N.L., Conibear, A.C., de Faoite, A.C., Heghinian, M.C., Adams, D.J., Mari, F., Craik, D.J.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Literature

Transforming conotoxins into cyclotides: Backbone cyclization of P-superfamily conotoxins.

Akcan, M., Clark, R.J., Daly, N.L., Conibear, A.C., de Faoite, A., Heghinian, M.D., Sahil, T., Adams, D.J., Mari, F., Craik, D.J.

(2015) Biopolymers 104: 682-692

• PubMed: 26172377 
• DOI: https://doi.org/10.1002/bip.22699
• Primary Citation Related Structures: 
  2MSO, 2MSQ


• PubMed Abstract: 
  

  Peptide backbone cyclization is a widely used approach to improve the activity and stability of small peptides but until recently it had not been applied to peptides with multiple disulfide bonds. Conotoxins are disulfide-rich conopeptides derived from the venoms of cone snails that have applications in drug design and development. However, because of their peptidic nature, they can suffer from poor bioavailability and poor stability in vivo. In this study two P-superfamily conotoxins, gm9a and bru9a, were backbone cyclized by joining the N- and C-termini with short peptide linkers using intramolecular native chemical ligation chemistry. The cyclized derivatives had conformations similar to the native peptides showing that backbone cyclization can be applied to three disulfide-bonded peptides with cystine knot motifs. Cyclic gm9a was more potent at high voltage-activated (HVA) calcium channels than its acyclic counterpart, highlighting the value of this approach in developing active and stable conotoxins containing cyclic cystine knot motifs.

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Organizational Affiliation: 
• Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia.
Health Innovations Research Institute, RMIT University, Bundoora, VIC, 3083, Australia.
Department of Chemistry and Biochemistry, Florida Atlantic University, FL, 33431, USA.
Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia.

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 2.81 kDa 
• Atom Count: 191 
• Modeled Residue Count: 27 
• Deposited Residue Count: 27 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Conotoxin cBru9a	A	27	synthetic construct	Mutation(s): 0

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
HYP	A	L-PEPTIDE LINKING	C5 H9 N O3		PRO

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Structure Validation

Entry History 

Deposition Data

• Released Date: 2015-07-22 
Deposition Author(s): Akcan, M., Clark, R.J., Daly, N.L., Conibear, A.C., de Faoite, A.C., Heghinian, M.C., Adams, D.J., Mari, F., Craik, D.J.

Revision History  

• Version 1.0: 2015-07-22
  Type: Initial release
  
• Version 1.1: 2015-12-09
  Changes: Database references
• Version 1.2: 2016-02-03
  Changes: Database references
• Version 1.3: 2023-06-14
  Changes: Data collection, Database references, Derived calculations, Other