5NHW

CRYSTAL STRUCTURE OF THE BIMAGRUMAB Fab

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.179 

wwPDB Validation 3D Report Full Report



Literature

Blockade of activin type II receptors with a dual anti-ActRIIA/IIB antibody is critical to promote maximal skeletal muscle hypertrophy.

Morvan, F., Rondeau, J.M., Zou, C., Minetti, G., Scheufler, C., Scharenberg, M., Jacobi, C., Brebbia, P., Ritter, V., Toussaint, G., Koelbing, C., Leber, X., Schilb, A., Witte, F., Lehmann, S., Koch, E., Geisse, S., Glass, D.J., Lach-Trifilieff, E.

(2017) Proc Natl Acad Sci U S A 114: 12448-12453

  • DOI: 10.1073/pnas.1707925114
  • Structures With Same Primary Citation

  • PubMed Abstract: 

    • The TGF-β family ligands myostatin, GDF11, and activins are negative regulators of skeletal muscle mass, which have been reported to primarily signal via the ActRIIB receptor on skeletal muscle and thereby induce muscle wasting described as cachexia. ...

    The TGF-β family ligands myostatin, GDF11, and activins are negative regulators of skeletal muscle mass, which have been reported to primarily signal via the ActRIIB receptor on skeletal muscle and thereby induce muscle wasting described as cachexia. Use of a soluble ActRIIB-Fc "trap," to block myostatin pathway signaling in normal or cachectic mice leads to hypertrophy or prevention of muscle loss, perhaps suggesting that the ActRIIB receptor is primarily responsible for muscle growth regulation. Genetic evidence demonstrates however that both ActRIIB- and ActRIIA-deficient mice display a hypertrophic phenotype. Here, we describe the mode of action of bimagrumab (BYM338), as a human dual-specific anti-ActRIIA/ActRIIB antibody, at the molecular and cellular levels. As shown by X-ray analysis, bimagrumab binds to both ActRIIA and ActRIIB ligand binding domains in a competitive manner at the critical myostatin/activin binding site, hence preventing signal transduction through either ActRII. Myostatin and the activins are capable of binding to both ActRIIA and ActRIIB, with different affinities. However, blockade of either single receptor through the use of specific anti-ActRIIA or anti-ActRIIB antibodies achieves only a partial signaling blockade upon myostatin or activin A stimulation, and this leads to only a small increase in muscle mass. Complete neutralization and maximal anabolic response are achieved only by simultaneous blockade of both receptors. These findings demonstrate the importance of ActRIIA in addition to ActRIIB in mediating myostatin and activin signaling and highlight the need for blocking both receptors to achieve a strong functional benefit.

    Organizational Affiliation: 

    MusculoSkeletal Diseases, Novartis Institutes for Biomedical Research, 4002 Basel, Switzerland; estelle.trifilieff@novartis.com.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
anti-human ActRII Bimagrumab Fab heavy-chainH236Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
anti-human ActRII Bimagrumab Fab light-chainL216Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL
Download CCD File 
H, L
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA		HL-PEPTIDE LINKINGC5 H7 N O3GLN
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.179 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.021α = 90
b = 78.016β = 90
c = 131.288γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
PHASERphasing
BUSTERrefinement
PDB_EXTRACTdata extraction
HKLdata reduction

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

  • Deposited Date: 2017-03-22 
  • Released Date: 2017-11-15 
    • Deposition Author(s): Rondeau, J.-M.

Revision History 

  • Version 1.0: 2017-11-15
    Type: Initial release
  • Version 1.1: 2017-11-29
    Changes: Database references
  • Version 2.0: 2020-03-11
    Changes: Polymer sequence