Lead ion (Pb²⁺)

The lead ion (Pb²⁺) is the predominant bioactive form of lead, a heavy metal with atomic number 82 and high density[1][3][7][9]. It is an environmental toxicant with no known physiological function in humans or other organisms[8]. The cation Pb²⁺ mimics calcium ions, interfering with calcium-dependent cellular processes and homeostasis, and binds to various biomolecules, replacing essential metals in proteins, enzymes, and regulatory cofactors[2][4][6]. Lead exposure disrupts signaling, impairs neurodevelopment, and causes widespread systemic toxicity. Lead enters cells via calcium channels and binds to proteins such as calmodulin, metalloproteins, and enzymes—especially δ-aminolevulinic acid dehydratase (ALAD), contributing to heme synthesis inhibition and anemia as well as neurological symptoms[2][4]. Lead poisoning is managed therapeutically by chelating agents that bind Pb²⁺, facilitating renal excretion[2]. There is no safe level of Pb²⁺ in blood; occupational and environmental exposure is strictly regulated due to severe long-term health risks for all age groups[8]. Lead ion is not a classical drug target but is a major focus in diagnostics, public health, and toxicology.

Other names

Lead(II) ionPlumbous ionPb²⁺

Chelators bind Pb²⁺, forming complexes to enhance its excretion and reduce tissue binding