Molecule of the Month: Lead Poisoning
Lead ions poison proteins throughout the body, blocking their normal function.
Blocking Heme Production
Lead and Calcium
Exploring the Structure
ALAD and Heavy Metal Poisons (PDB entries 1ylv, 1qnv, 1qml)
Enzymes use specific arrangements of amino acids to capture zinc and calcium ions. In ALAD, three cysteine amino acids are arranged in a triangle to coordinate zinc ions, and proteins like calmodulin often use acidic amino acids to capture calcium. Lead is more agnostic than these two ions and can bind to both types of sites. Click on the image to take a closer look at zinc, lead and mercury binding sites in ALAD (PDB entries 1ylv, 1qnv, 1qml).
Topics for Further Discussion
- Several dozen structures of lead bound to proteins are available at the PDB—try looking at the Ligand Summary page for lead to find them.
- You can also find structures for metalloproteins that might be sensitive to lead poisoning by using the Ligand Summary page for calcium and the Ligand Summary page for zinc.
April 2016, David Goodselldoi:10.2210/rcsb_pdb/mom_2016_4