BMS3020 L4 Iron and Disease 30/10/18
BMS3020 CHRONIC DISEASE
LECTURE 4 – Molecular Mechanisms of Human Iron
Distribution
Iron Deficiency
According to World Health Organisation:
- Most common, widespread nutritional disorder in the world
- Affects women and children in developing countries and is significantly prevalent in
industrialised countries
- 2 billion people (over 30% of world population) are anaemic often due to iron deficiency
- Large proportion of world population rely on a plant diet for nutrition, and plants do not
contain as much iron as a high-meat diet does
- 1 in 2 pregnant women and about 40% of preschool children in developing countries are
estimated to be anaemic
- Iron deficiency anaemia is augmented by worm infections, malaria and other infectious
diseases such as HIV and tuberculosis
- Major health consequences including poor pregnancy outcome, impaired physical and
cognitive development, increased risk of morbidity in children and reduced work
productivity in adults
- Anaemia contributes to 20% of all maternal deaths
Iron Enzymes
- Found in haem, in Fe-S clusters and in active site of iron
proteins
- Many iron enzymes within cells and some are very
important:
o DNA primase in DNA replication
o DNA repair helicases
o Transcription regulation enzymes e.g. pirin
o mRNA translation enzymes e.g. ABCE1
o Nucleotide synthesis enzymes e.g. ribonucleotide
reductase
o Respiratory chain enzymes
o Insertion of iron to haem by ferrochelatase
Iron Homeostasis
Acquisition:
- Oxidation of ferrous iron in air
Fe2+ Fe3+
- Formation of insoluble ferric oxide-hydroxide species
- Iron (II) is very soluble but iron (III) is not:
o Earth was initially in a reducing environment when biology began so most of biology
has evolved using Fe2+
o When it moved into an oxygenated environment Fe 2+ was converted to Fe3+ and fell
out of solution – therefore, less biologically available
o Life has had to evolve mechanisms to acquire Fe3+ which is insoluble
1
BMS3020 CHRONIC DISEASE
LECTURE 4 – Molecular Mechanisms of Human Iron
Distribution
Iron Deficiency
According to World Health Organisation:
- Most common, widespread nutritional disorder in the world
- Affects women and children in developing countries and is significantly prevalent in
industrialised countries
- 2 billion people (over 30% of world population) are anaemic often due to iron deficiency
- Large proportion of world population rely on a plant diet for nutrition, and plants do not
contain as much iron as a high-meat diet does
- 1 in 2 pregnant women and about 40% of preschool children in developing countries are
estimated to be anaemic
- Iron deficiency anaemia is augmented by worm infections, malaria and other infectious
diseases such as HIV and tuberculosis
- Major health consequences including poor pregnancy outcome, impaired physical and
cognitive development, increased risk of morbidity in children and reduced work
productivity in adults
- Anaemia contributes to 20% of all maternal deaths
Iron Enzymes
- Found in haem, in Fe-S clusters and in active site of iron
proteins
- Many iron enzymes within cells and some are very
important:
o DNA primase in DNA replication
o DNA repair helicases
o Transcription regulation enzymes e.g. pirin
o mRNA translation enzymes e.g. ABCE1
o Nucleotide synthesis enzymes e.g. ribonucleotide
reductase
o Respiratory chain enzymes
o Insertion of iron to haem by ferrochelatase
Iron Homeostasis
Acquisition:
- Oxidation of ferrous iron in air
Fe2+ Fe3+
- Formation of insoluble ferric oxide-hydroxide species
- Iron (II) is very soluble but iron (III) is not:
o Earth was initially in a reducing environment when biology began so most of biology
has evolved using Fe2+
o When it moved into an oxygenated environment Fe 2+ was converted to Fe3+ and fell
out of solution – therefore, less biologically available
o Life has had to evolve mechanisms to acquire Fe3+ which is insoluble
1
