Note_MetalIons – MetalIons

WID Note_MetalIons
Name MetalIons
Comments Physiology Metal ions are critical to cellular physiology [PUB_0624]: Bind approximately 25% of proteins, usually inside cavities and clefts and not accessible to solvent Interact with all charged and polar groups of liquid-containing biopolymers Stabilize folded proteins Enable active conformations Provide unique chemistry needed for catalysis Act as second messengers Physical properties [PUB_0624, PUB_0625] Large ions have low solubility (Zn2+, Mn2+, Cu2+, Fe2+, Fe3+) Protein binding site selectivity usually inversely proportional to ion concentration Divalent, trivalent ions have slow dissociation rates Dissociation constants for Ca2+, Mg2+, Na+, and K+ usually comparable to intracellular ion concentration Ca2+ dissociation constant 10-9 - 10-5 M Complex stability: Ca2+ < Mg2+ < Mn2+ < Fe2+ < Cd2+ < Co2+ < Zn2+ < Ni2+ < Cu2+ < Fe3+ Several ions almost always bind to oxygen: Ca2+, Mg2+, Na+, K+; Other di- and trivalent ions bind to N, S, and O H+ and Ca2+ complete for binding sites IonBindingMobilityFunction Na+, K+weakhighcharge carrier Mg2+, Ca2+signaling, structure Zn2+lewis acid, structure Fe2+, Cu2+, Mn2+, Mo2+stronglowredox chemistry Metal binding macromolecule families [PUB_0624] FamilyIonsNotes EF-hand proteinCa2+ Zn-finger proteinZn2+ DNAMg2+, K+, Na+K+ binds major groove, Na+ binds minor groove RNAMg2+, K+2.1-4 nt/metal ion [PUB_0679] Metal binding protein characterization Metal binding proteins are characterized by the following [PUB_0624]: Stoichiometry Binding constant Cooperativity ΔG, ΔH ΔS Kinetics Structural changes upon binding Functional changes upon binding
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  2. Feig AL, Uhlenbeck OC. Eds Gesteland RF, Cech TR, Atkins JF. . Cold Spring Harbor Laboratory Press (1999). WholeCell: PUB_0679, ISBN: 9780879697396, URL:

  3. Permyakov E. Metalloproteomics. Wiley-Interscience: Hoboken, NJ (2009). WholeCell: PUB_0624, ISBN: 9780470392485, URL:

Created 2012-10-01 15:07:34
Last updated 2012-10-01 15:13:58