9OLA | pdb_00009ola

Backbone-modified parallel beta hairpin (PBH): N-alpha-amino Tyrosine at position 15

• PDB DOI: https://doi.org/10.2210/pdb9OLA/pdb
• BMRB: 31243

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


• Deposited: 2025-05-12 Released: 2025-12-03 
• Deposition Author(s): Starnes, S.K., Horne, W.S., Del Valle, J.R.
• Funding Organization(s): National Science Foundation (NSF, United States), National Institutes of Health/National Institute on Aging (NIH/NIA), National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Literature

Impact of Strand Edge N-Amination on the Stability of a Parallel beta-Hairpin Fold.

Starnes, S.K., Horne, W.S., Del Valle, J.R.

(2025) J Org Chem 90: 17214-17220

• PubMed: 41264875 
• DOI: https://doi.org/10.1021/acs.joc.5c02479
• Primary Citation Related Structures: 
  9OL7, 9OL8, 9OL9, 9OLA


• PubMed Abstract: 
  

  Peptide backbone N-amination has emerged as a useful strategy to stabilize antiparallel β-sheet structure. Here, we used circular dichroism and NMR to evaluate the impact of amide-to-hydrazide substitution on the folded population of a parallel β-hairpin model. Outer-edge N-amination was well tolerated and resulted in enhanced stability relative to N-methylation. High-resolution NMR structures confirmed that the α-hydrazino acid residues adopt canonical parallel β-strand torsions that are compatible with the formation of intraresidue C6 hydrogen bonds involving the hydrazide NH ₂ group.

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Organizational Affiliation: 
• Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States.
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 2.01 kDa 
• Atom Count: 143 
• Modeled Residue Count: 18 
• Deposited Residue Count: 18 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
(ACE)SKTFIQV(DPR)(4G6) peptide	A	10	synthetic construct	Mutation(s): 0

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
(ACE)KNVL(A1CCQ)RR peptide	B	8	synthetic construct	Mutation(s): 0

Small Molecules

Modified Residues  2 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
DPR	A	D-PEPTIDE LINKING	C5 H9 N O2		--
A1CCQ	B	L-PEPTIDE LINKING	C9 H12 N2 O3		TYR

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2025-12-03 
Deposition Author(s): Starnes, S.K., Horne, W.S., Del Valle, J.R.

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Funding Organization	Location	Grant Number
National Science Foundation (NSF, United States)	United States	CHE2109008
National Institutes of Health/National Institute on Aging (NIH/NIA)	United States	R01 AG074570
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)	United States	R35GM149220

Revision History  

• Version 1.0: 2025-12-03
  Type: Initial release
  
• Version 1.1: 2025-12-17
  Changes: Database references