2RMI

3D NMR structure of astressin

• PDB DOI: https://doi.org/10.2210/pdb2RMI/pdb

• Classification: NEUROPEPTIDE
• Mutation(s): No 


• Deposited: 2007-10-17 Released: 2007-10-30 
• Deposition Author(s): Royappa, G.C.R., Cervini, L., Gulyas, J., Rivier, J., Riek, R.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Literature

Astressin-amide and astressin-acid are structurally different in dimethylsulfoxide

Grace, C.R., Cervini, L., Gulyas, J., Rivier, J., Riek, R.

(2007) Biopolymers 87: 196-205

• PubMed: 17657708 
• DOI: https://doi.org/10.1002/bip.20818
• Primary Citation of Related Structures:  
  2RMI


• PubMed Abstract: 
  

  The C-terminally amidated CRF antagonist astressin binds to CRF-R1 or CRF-R2 receptors with low nanomolar affinity while the corresponding astressin-acid has >100 times less affinity. To understand the role of the amide group in binding, the conformations of astressin-amide and astressin-acid were studied in DMSO using NMR techniques. The 3D NMR structures show that the backbones of both analogs prefer an alpha-helical conformation, with a small kink around Gln(26). However, astressin-amide has a well-defined helical structure from Leu(27) to Ile(41) and a conformation very similar to the bioactive conformation reported by our group (Grace et al., Proc Natl Acad Sci USA 2007, 104, 4858-4863). In contrast, astressin-acid has an irregular helical conformation from Arg(35) onward, including a rearrangement of the side chains in that region. This structural difference highlights the crucial role of the C-terminal amidation for stabilization of astressin's bioactive conformation.

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Organizational Affiliation: 

Structural Biology Laboratory, The Salk Institute for Biological Studies, LA Jolla, CA 92037, USA.

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 3.59 kDa 
• Atom Count: 251 
• Modelled Residue Count: 30 
• Deposited Residue Count: 30 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
astressin	A	30	N/A	Mutation(s): 0

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
NLE	A	L-PEPTIDE LINKING	C6 H13 N O2		LEU

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Structure Validation

Entry History 

Deposition Data

• Released Date: 2007-10-30 
Deposition Author(s): Royappa, G.C.R., Cervini, L., Gulyas, J., Rivier, J., Riek, R.

Revision History  

• Version 1.0: 2007-10-30
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2022-03-16
  Changes: Database references, Derived calculations