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PDBsum entry 5dyh

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protein ligands metals Protein-protein interface(s) links
Metal transport PDB id
5dyh

 

 

 

 

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Contents
Protein chains
677 a.a.
Ligands
CIT ×11
CO3 ×2
Metals
4TI ×2
PDB id:
5dyh
Name: Metal transport
Title: Ti(iv) bound human serum transferrin
Structure: Serotransferrin. Chain: a, b. Synonym: transferrin,beta-1 metal-binding globulin,siderophilin. Engineered: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: tf, pro1400. Expressed in: oryza sativa. Expression_system_taxid: 4530
Resolution:
2.68Å     R-factor:   0.204     R-free:   0.237
Authors: M.Saxena,S.Sharma,N.Noinaj,T.B.Parks,A.D.Tinoco
Key ref: A.D.Tinoco et al. (2016). Unusual Synergism of Transferrin and Citrate in the Regulation of Ti(IV) Speciation, Transport, and Toxicity. J Am Chem Soc, 138, 5659-5665. PubMed id: 27070073 DOI: 10.1021/jacs.6b01966
Date:
24-Sep-15     Release date:   27-Apr-16    
PROCHECK
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 Headers
 References

Protein chains
Pfam   ArchSchema ?
P02787  (TRFE_HUMAN) -  Serotransferrin from Homo sapiens
Seq:
Struc:
 
Seq:
Struc:
698 a.a.
677 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 

 
DOI no: 10.1021/jacs.6b01966 J Am Chem Soc 138:5659-5665 (2016)
PubMed id: 27070073  
 
 
Unusual Synergism of Transferrin and Citrate in the Regulation of Ti(IV) Speciation, Transport, and Toxicity.
A.D.Tinoco, M.Saxena, S.Sharma, N.Noinaj, Y.Delgado, E.P.Quiñones González, S.E.Conklin, N.Zambrana, S.A.Loza-Rosas, T.B.Parks.
 
  ABSTRACT  
 
Human serum transferrin (sTf) is a protein that mediates the transport of iron from blood to cells. Assisted by the synergistic anion carbonate, sTf transports Fe(III) by binding the metal ion in a closed conformation. Previous studies suggest sTf's role as a potential transporter of other metals such as titanium. Ti is a widely used metal in colorants, foods, and implants. A substantial amount of Ti is leached into blood from these implants. However, the fate of the leached Ti and its transport into the cells is not known. Understanding Ti interaction with sTf assumes a greater significance with our ever increasing exposure to Ti in the form of implants. On the basis of in vitro studies, it was speculated that transferrin can bind Ti(IV) assisted by a synergistic anion. However, the role and identity of the synergistic anion(s) and the conformational state in which sTf binds Ti(IV) are not known. Here we have solved the first X-ray crystal structure of a Ti(IV)-bound sTf. We find that sTf binds Ti(IV) in an open conformation with both carbonate and citrate as synergistic anions at the metal binding sites, an unprecedented role for citrate. Studies with cell lines suggest that Ti(IV)-sTf is transported into cells and that sTf and citrate regulate the metal's blood speciation and attenuate its cytotoxic property. Our results provide the first glimpse into the citrate-transferrin synergism in the regulation of Ti(IV) bioactivity and offers insight into the future design of Ti(IV)-based anticancer drugs.
 

 

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