Structure of Titanium-bound human serum transferrin

Experimental Data Snapshot

  • Resolution: 3.00 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 

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This is version 1.3 of the entry. See complete history


The role of citrate, lactate and transferrin in determining titanium release from surgical devices into human serum.

Curtin, J.P.Wang, M.Cheng, T.Jin, L.Sun, H.

(2018) J Biol Inorg Chem 23: 471-480

  • DOI: https://doi.org/10.1007/s00775-018-1557-5
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The presence of ionic titanium in the serum of patients with titanium implants is currently unexplained. This is presumed due to corrosion, and yet the serum titanium concentration measured in patients is far greater than that predicted by its solubility. The binding of titanium ion as Ti(IV) to human transferrin (hTF) in serum indicates that Ti(IV) ions interact with human physiology. This is an intriguing finding since there is currently no known role for titanium ions in human physiology. Thus, understanding the factors that determine in vivo titanium ion release is relevant to further understanding this metal's interactions with human biochemistry. The present study sought to determine the extent of titanium ion release of into human serum in vitro, and the role of citrate, lactate and hTF in this process. It was found that, when surgical devices of commercially pure titanium were placed into human serum, citrate and lactate concentrations were the prime determinants of titanium release. Crystallography revealed Ti(IV) bound to hTF in the presence of citrate alone, signalling that citrate can act as an independent ligand for Ti(IV) binding to hTF. Based on these findings, a two-stage process of titanium ion release into human serum that is dependent upon both citrate and hTF is proposed to explain the ongoing presence of titanium ion in human subjects with implanted titanium devices.

  • Organizational Affiliation

    Faculty of Dentistry, The University of Hong Kong, Hong Kong, China. jpcurtin@hku.hk.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serotransferrin679Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P02787 (Homo sapiens)
Explore P02787 
Go to UniProtKB:  P02787
PHAROS:  P02787
GTEx:  ENSG00000091513 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02787
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.00 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.170 
  • R-Value Observed: 0.172 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 138.977α = 90
b = 156.667β = 90
c = 107.855γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
The University of Hong KongHong Kong8100013

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-08
    Type: Initial release
  • Version 1.1: 2018-04-25
    Changes: Data collection, Database references
  • Version 1.2: 2018-05-23
    Changes: Data collection, Database references
  • Version 1.3: 2023-11-08
    Changes: Data collection, Database references, Refinement description