Hemoglobin structure

zeta and epsilon

chains that peak shortly after conception, decline dramatically and are not detectable after 3 months in utero

alpha chains

begin at approximately 19 days post-conception, rise rapidly in the first 3 months of gestation, and remain throughout life

gamma chains

begin shortly after conception, rise rapidly to 4-5 month gestation, decrease at birth adn are berely detectable after 6 months

beta chains

begin shortly after conception, rise slowly during gestation, reach significant levelt at 3 months, peak ata 6 months and remain throughout life

delta chains

begin about 6 months in utero, plateau at 6 months and remain at this level throughout life

Hgb A

alpha and beta chains
97% total hbg in adults
20% total hbg in newborns

Hgb A2

alpha and delta chains
2.5% total hbg in adults
<1% total hbg in newborns

Hgb F

alpha and gamma chains
<1% total hbg in adults
80% total hbg in newborns

Hgb Gower 1

zeta and epsilon chains
embryonic hgb

Hgb gower 2

alpha and epsilon chains
embryonic hgb

Hgb Portland

zeta and gamma chains
embryonic hgb

Thalassemia

disease in which one or more of the 6 normal globin genes are mutated resulting in a deficiency of one or more globin chains reducing the corresponding type of hemoglobin

Alpha thalassemia

affect HbA, HbA2, and HbF

Beta thalassemia

Affects HbA

secondary structure

alpha helix vs beta pleated sheet, proline kinks

tertiary structure

3D folding pattern
Globular

Quaternary structure

tetrameric
2 alpha-like chains
2 beta like chains

contact points

alpha1beta1 to alpha2beta2

beta gap

pocket in the inner core of the globin chains
enlarges in deoxyhemoglobin

allosteric change

movement of the globin molecules as hemoglobin converts from oxyhemoglobin to deoxyhemoglobin