7EK7

prawn ferritin to coordinate with heavy metal ions

Summary for 7EK7

• Entry DOI: 10.2210/pdb7ek7/pdb
• Descriptor: Ferritin, MERCURY (II) ION (3 entities in total)
• Functional Keywords: heavy metal ion removal, prawn ferritin, cysteine, hg, metal binding protein
• Biological source: Marsupenaeus japonicus (Kuruma prawn)
• Total number of polymer chains: 6
• Total formula weight: 117134.55

Authors

Wang, Y.,Zang, J. (deposition date: 2021-04-04, release date: 2021-12-29, Last modification date: 2023-11-29)

Primary citation

Wang, Y.,Zang, J.,Wang, C.,Zhang, X.,Zhao, G.
Structural Insights for the Stronger Ability of Shrimp Ferritin to Coordinate with Heavy Metal Ions as Compared to Human H-Chain Ferritin.
Int J Mol Sci, 22:-, 2021

PubMed Abstract: Although apoferritin has been widely utilized as a new class of natural protein nanovehicles for encapsulation and delivery of nutraceuticals, its ability to remove metal heavy ions has yet to be explored. In this study, for the first time, we demonstrated that the ferritin from kuruma prawns (), named MjF, has a pronouncedly larger ability to resist denaturation induced by Cd and Hg as compared to its analogue, human H-chain ferritin (HuHF), despite the fact that these two proteins share a high similarity in protein structure. Treatment of HuHF with Cd or Hg at a metal ion/protein shell ratio of 100/1 resulted in marked protein aggregation, while the MjF solution was kept constantly clear upon treatment with Cd and Hg at different protein shell/metal ion ratios (50/1, 100/1, 250/1, 500/1, 1000/1, and 2500/1). Structural comparison analyses in conjunction with the newly solved crystal structure of the complex of MjF plus Cd or Hg revealed that cysteine (Cys) is a major residue responsible for such binding, and that the large difference in the ability to resist denaturation induced by these two heavy metal ions between MjF and HuHF is mainly derived from the different positions of Cys residues in these two proteins; namely, Cys residues in HuHF are located on the outer surface, while Cys residues from MjF are buried within the protein shell. All of these findings raise the high possibility that prawn ferritin, as a food-derived protein, could be developed into a novel bio-template to remove heavy metal ions from contaminated food systems.

PubMed: 34360624
DOI: 10.3390/ijms22157859

Experimental method

X-RAY DIFFRACTION (2.7 Å)