7SPE

Crystal structure of sperm whale myoglobin variant sMb5(O2beY)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history


Literature

Tuning Enzyme Thermostability via Computationally Guided Covalent Stapling and Structural Basis of Enhanced Stabilization.

Iannuzzelli, J.A.Bacik, J.P.Moore, E.J.Shen, Z.Irving, E.M.Vargas, D.A.Khare, S.D.Ando, N.Fasan, R.

(2022) Biochemistry 61: 1041-1054

  • DOI: https://doi.org/10.1021/acs.biochem.2c00033
  • Primary Citation of Related Structures:  
    7SPE, 7SPF, 7SPG, 7SPH

  • PubMed Abstract: 

    Enhancing the thermostability of enzymes without impacting their catalytic function represents an important yet challenging goal in protein engineering and biocatalysis. We recently introduced a novel method for enzyme thermostabilization that relies on the computationally guided installation of genetically encoded thioether "staples" into a protein via cysteine alkylation with the noncanonical amino acid O -2-bromoethyl tyrosine (O2beY). Here, we demonstrate the functionality of an expanded set of electrophilic amino acids featuring chloroacetamido, acrylamido, and vinylsulfonamido side-chain groups for protein stapling using this strategy. Using a myoglobin-based cyclopropanase as a model enzyme, our studies show that covalent stapling with p -chloroacetamido-phenylalanine (pCaaF) provides higher stapling efficiency and enhanced stability (thermodynamic and kinetic) compared to the other stapled variants and the parent protein. Interestingly, molecular simulations of conformational flexibility of the cross-links show that the pCaaF staple allows fewer energetically feasible conformers than the other staples, and this property may be a broader indicator of stability enhancement. Using this strategy, pCaaF-stapled variants with significantly enhanced stability against thermal denaturation (Δ T m ' = +27 °C) and temperature-induced heme loss (Δ T 50 = +30 °C) were obtained while maintaining high levels of catalytic activity and stereoselectivity. Crystallographic analyses of singly and doubly stapled variants provide key insights into the structural basis for stabilization, which includes both direct interactions of the staples with protein residues and indirect interactions through adjacent residues involved in heme binding. This work expands the toolbox of protein stapling strategies available for protein stabilization.


  • Organizational Affiliation

    Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Myoglobin154Physeter catodonMutation(s): 0 
Gene Names: MB
EC: 1.11.1 (UniProt), 1.7 (UniProt)
UniProt
Find proteins for P02185 (Physeter macrocephalus)
Explore P02185 
Go to UniProtKB:  P02185
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02185
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.184 
  • R-Value Observed: 0.186 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.436α = 90
b = 54.339β = 90
c = 76.583γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not fundedUnited StatesCBET-1929256

Revision History  (Full details and data files)

  • Version 1.0: 2022-06-01
    Type: Initial release
  • Version 1.1: 2022-11-30
    Changes: Database references
  • Version 1.2: 2023-10-25
    Changes: Data collection, Refinement description