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Case Studies in Mercury and Cadmium
Toxicity
Val Culotta, PhD
Johns Hopkins University
Section A
Basic Overview of Metal Toxicity
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Periodic Classification of the Elements
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Essential vs. Non-Essential Metal Ions in
Biology
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Chelation Methods of Therapy for Metal Toxicity
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Endogenous Protection against Metal Toxicity
! Metallothionein
- High cysteine content (30%)
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A Cysteine-Rich Metallothionein
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Endogenous Protection against Metal Toxicity
! Metallothionein
- High cysteine content (30%)
- High metal content (8–12 atoms/molecule)
- Low molecular weight
- Inducible at level of gene expression metals
(Cd, Hg, Cu, Zn)
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Essential vs. Non-Essential Metal Ions in Biology
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Endogenous Protection against Metal Toxicity
! Function
- Metal detoxification
- Metal homeostasis
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Factors that Affect Metal Toxicity
! Level and duration of exposure
! Chemical form of metal
! Metal-protein complexes
! Host factors
- Lifestyle
- Gender
- Age
- Immune status
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