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Transition Metals. Periodic Table. bulk elements. for some species. trace elements. General roles of metal ions in biology. Na, K: Charge carriers Osmotic and electrochemical gradients Nerve function. Mg, Ca: Enzyme activators Structure promoters Lewis acids - PowerPoint PPT Presentation
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Transition MetalsTransition MetalsTransition MetalsTransition Metals
bulk elements
trace elements
for some species
Periodic Table
General roles of metal ions in biologyNa, K:Na, K: Charge carriers
Osmotic and electrochemical gradients
Nerve function
Mg, Ca:Mg, Ca: Enzyme activators
Structure promoters
Lewis acids
Mg2+: chlorophyll, photosynthesis
Ca2+: insoluble phosphates
Other metal ions: less well defined and Other metal ions: less well defined and more more
obscure rolesobscure roles
Zn:Zn: Metalloenzymes
Structure promoters
Lewis acid
Not a redox catalyst!
Fe, Cu, Mo:Fe, Cu, Mo: Electron-transfer
Redox proteins and enzymes
Oxygen carrying proteins
Nitrogen fixation
Biochemical ReactivityBiochemical Reactivity
Promotion of Appropriate Geometry Change acid/base character Change Redox potentials Change ionic concentration Formation of Unique species Formation of structural materials Activation of small molecules (NO)
Fe(II), Fe(III):Fe(II), Fe(III):
Essential for ALL organisms
In plants: iron deficiency
In human body: 4-5 g
Uptake: ~ 1 mg/day
In human bodyIn human body
75% Hem-iron75% Hem-iron
Hemoglobin Myoglobin Cytochromes Oxidases, P-450
25% Non-hem-iron25% Non-hem-iron
Rubredoxins Ferredoxins
PorphyrinsPorphyrins
FeFe Oxygen TransportOxygen Transport
Hemoglobin 4 Fe containing globin units (2-alpha and 2-beta) K increases with each O2 added Fe(II) does not oxidize to Fe(III)
Non-aqueous or simultaneous Oxygen to two hemes.
Oxygen StorageOxygen Storage Myoglobin
1 heme group
Porphyrin
HemoglobinHemoglobin
FeFe
Iron Environment in Iron Environment in MyoglobinMyoglobin
Cytochromes, Peroxidases, Cytochromes, Peroxidases, and Catalasesand Catalases
Cytochrome P-450Cytochrome P-450
Oxidation catalyst
Peroxidases/CatalasesPeroxidases/Catalases
Decomposition of organic peroxides.
Electron Transfer ChainsElectron Transfer Chains
Other Fe CompoundsOther Fe Compounds
Ferritin / TransferrinFerritin / Transferrin
Iron storage in spleen, liver and marrow.
Mw 445,000 (4,300 Fe atoms)
bulk elements
trace elements
for some species
Periodic Table
Cu(I), Cu(II)Cu(I), Cu(II)
PlantsPlants Electron transfer
AnimalsAnimals O2-carrying
Protection of DNA
from O2-
Cu-proteins and enzymesCu-proteins and enzymes
Cytochrome oxidase O2 H2O
Tyrosinase, phenol oxidase ox. of phenols
Ceruloplasmin Fe(II) Fe(III)
Blue proteins Electron transfer
Superoxide dismutase Elimination of O2-
Hemocyanin O2 transport
Superoxide DismutaseSuperoxide Dismutase
SOD-Cu2+ + O2.- SOD-Cu1+ + O2
SOD-Cu1+ + O2.- + 2H+ SOD-Cu2+ + H2O2
Oxygen hemocyaninOxygen hemocyaninmollusks and arthropodsmollusks and arthropods
1. Wilson’s disease:
Hereditary disfunction of ceruloplasminCu2+ accumulates in liver, brain: dementia, liver failureAdministration: Cu-specific chelate
2. Menke’s „kinky hair” syndrome:
Hereditary disfunction of intracellular copper transportCopper deficiency symptoms: disturbances in the mental and physical developmentTherapy: intravenously administered copper compounds
3. Acute copper deficiency
Insufficient oxygen utilization in brain
4. Mutations in the copper dependent superoxide dismutase
Copper-related Pathological Disorders
Ni(II)Ni(II)
Ni-containing enzymes of bacteria
Urease (Vesicle)
CO-dehydrogenase
Hydrogenases Membranes
MoMoHPO4
2-
Uptake : MoOMoO442-2-
SO42-
Molybdenium enzymesMolybdenium enzymes
Nitrogenase N2 NH3
Aldehyde oxidases -CHO -COOH
Nitrate reductase NO3- NO2
-
Sulfide oxidase SO32- SO4
2-
Xanthin oxidase purin catabolism
Formate dehydrogenase H-COO- CO2
Platinum Complexes in Cancer Therapy
NH3
NH3Cl
Cl
Pt
Cis-dichlorodiammineplatinum (II)
Blocking cell division
NH3
NH3Cl
Cl
Pt
Trans-dichlorodiammineplatinum (II)inactive
Cis-tetrachlorodiammineplatinum (IV)
biologically active
NH3
NH3Cl
Cl
Pt
Cl
ClTrans-tetrachlorodiammineplatinum (IV)
inactive
NH3
NH3 Cl
Cl
Pt
Cl
Cl
NN
NH2
O
NH N
N
N
NH2
O
NH3
NH3
Pt
NN HN
NH2
N
N
N
Pt
NH3
NH3
Cisplatin
NH3
NH3 Cl
Cl
Pt
Platinum Complexes in Cancer Therapy
a b
G
G
NH3
NH3
Protein
NH3
G NH3
Pt
Pt
Pt
NH3
NH3
PtNH3
NH3
Protein
Platinum Complexes in Cancer Therapy
Injection
Blood
Toxic side effect Cytostatic effect
Plasma proteins Blood stream
Kidney Tumor cellsOther organs
Liver
Excretion
Activity of Pt(NH3)2X2 complexes
X Activity
NO3- toxic
H2O toxic
Cl- antitumor
Br- antitumor
I- inactive
SCN- inactive
NO2- inactive
CN- inactive
(X = ligand)
C
C
OO
OO
Pt NH3
NH3
a Pt-chelate complex(considerable antitumor activity)