Structure of the complement C5 specific nanobody TPP-3444

Experimental Data Snapshot

  • Resolution: 1.30 Å
  • R-Value Free: 0.175 
  • R-Value Work: 0.146 
  • R-Value Observed: 0.148 

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Characterization of the bispecific VHH antibody gefurulimab (ALXN1720) targeting complement component 5, and designed for low volume subcutaneous administration.

Jindal, S.Pedersen, D.V.Gera, N.Chandler, J.Patel, R.Neill, A.Cone, J.Zhang, Y.Yuan, C.X.Millman, E.E.Carlin, D.Puffer, B.Sheridan, D.Andersen, G.R.Tamburini, P.

(2023) Mol Immunol 165: 29-41

  • DOI: https://doi.org/10.1016/j.molimm.2023.12.004
  • Primary Citation of Related Structures:  
    8COE, 8COH

  • PubMed Abstract: 

    The bispecific antibody gefurulimab (also known as ALXN1720) was developed to provide patients with a subcutaneous treatment option for chronic disorders involving activation of the terminal complement pathway. Gefurulimab blocks the enzymatic cleavage of complement component 5 (C5) into the biologically active C5a and C5b fragments, which triggers activation of the terminal complement cascade. Heavy-chain variable region antigen-binding fragment (VHH) antibodies targeting C5 and human serum albumin (HSA) were isolated from llama immune-based libraries and humanized. Gefurulimab comprises an N-terminal albumin-binding VHH connected to a C-terminal C5-binding VHH via a flexible linker. The purified bispecific VHH antibody has the expected exact size by mass spectrometry and can be formulated at greater than 100 mg/mL. Gefurulimab binds tightly to human C5 and HSA with dissociation rate constants at pH 7.4 of 54 pM and 0.9 nM, respectively, and cross-reacts with C5 and serum albumin from cynomolgus monkeys. Gefurulimab can associate with C5 and albumin simultaneously, and potently inhibits the terminal complement activity from human serum initiated by any of the three complement pathways in Wieslab assays. Electron microscopy and X-ray crystallography revealed that the isolated C5-binding VHH recognizes the macroglobulin (MG) 4 and MG5 domains of the antigen and thereby is suggested to sterically prevent C5 binding to its activating convertase. Gefurulimab also inhibits complement activity supported by the rare C5 allelic variant featuring an R885H substitution in the MG7 domain. Taken together, these data suggest that gefurulimab may be a promising candidate for the potential treatment of complement-mediated disorders.

  • Organizational Affiliation

    Alexion, AstraZeneca Rare Disease, 100 College Street, New Haven, CT 06510, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Nanobody TPP-3444132Lama glamaMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.30 Å
  • R-Value Free: 0.175 
  • R-Value Work: 0.146 
  • R-Value Observed: 0.148 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.489α = 90
b = 81.489β = 90
c = 36.601γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Other privateUnited States2018

Revision History  (Full details and data files)

  • Version 1.0: 2024-01-03
    Type: Initial release