Structure of Hemoglobin

HAEMOGLOBIN

• Haemoglobin a tetrameric protein of erythrocytes.
• A single heme consist of single iron in ferrous state (Fe⁺²).

 Structure of Hemoglobin-

• Secondary structure
• Tertiary structure
• Quaternary structure

 Genetics of alpha and Beta chains-

• α-like globin genes on chromosome 16.
• β-like globin genes on chromosome 11.

 Types of Hemoglobin-

Embryonic haemoglobins

1. Hb Portland ?₂γ₂
2. Hb Gower I- ?₂ε₂
3. Hb Gower II- α₂ε₂

Fetal Hemoglobins

1. Hb F- α₂γ₂

Adult Hemoglobins

1. Hb A₁ – α₂β₂
2. Hb A₂ – α₂δ₂

 Charateristics of Hemoglobin

• Slower electrophoretic mobility
• Increased resistance to Alkali Denaturation
• Decreased Interaction with 2, 3 BPG.

 Interactions of Hemoglobin with 2, 3 BPG

• 2, 3 BPG is an intermediate of Glycolysis.
• Synthesized of 2, 3 BPG shunt or Rapaport Leubering Cycle.
• Binding of 2, 3 BPG in the curve shifts ODC to right.

GLOBIN-

• Each polypeptide chain is made up of helical segments.
• Heme binding to hydrophobic pocket.

• A single heme consist of single iron in ferrous state (Fe⁺²).

Genetics of alpha and Beta chains-

• α-like globin genes on chromosome 16.
• β-like globin genes on chromosome 11.

Types of Hemoglobin-

Embryonic haemoglobins

1. Hb Portland ?₂γ₂
2. Hb Gower I- ?₂ε₂
3. Hb Gower II- α₂ε₂

Fetal Hemoglobins

1. Hb F- α₂γ₂

Adult Hemoglobins

1. Hb A₁ – α₂β₂
2. Hb A₂ – α₂δ₂ 

Charateristics of Hemoglobin

• Slower electrophoretic mobility
• Increased resistance to Alkali Denaturation
• Decreased Interaction with 2, 3 BPG.
• Binding of 2, 3 BPG in the curve shifts ODC to right.