Haemoglobin
By Maja & Jonathan
S
Protein Functions
S Iron-containing oxygen-transporting metallprotein
S Essential for respiration
S Located in all red blood cells of vertebrates
S Around 35% of our blood (including water)
S Four iron atoms; can bind up to four oxygen molecules
S Responsible for the red colour of blood (iron)
S carries the oxygen from the lungs or gills to the cells
History
S Many people did research for Heamogobin
S Discovered in 1840 by Hünefeld
S Description of revisable oxygenation by Felix Hoppe-Seyler
S 1959 Max Perutz determined protein structure; resulted in
Nobel prize for Chemistry in 1962
S Role in blood determined by Claude Bernard
Primary Structure
S The haemoglobin molecule consists of 4 polypeptide
(globin) chains. In adults there are 2 alpha chains and 2 beta
chains.
S Peptide bond between each amino acid called residues
Secondary Structure
S Joined amino acid
residues coil to
form sections of alpha
helix, which stabilizes
the structure
S Structure fairly
compact
Tertiary Structure
S
Main bonding involved in
stabilising the structure of each
haemoglobin chain is the
attachment of a haem group (a
porphyrin ring containing iron)
--->the yellow ball on the picture
S
No disulphide bridges involved in
the tertiary structure of
haemoglobin.
Quaternary Structure
S
Two alpha and two beta chains
are associated to form a
haemoglobin molecule.
S
More than one peptide chain
(multimeric proteins). The
manner in which these chains fit
together (sort of like a puzzle) is
the quaternary structure.
Defective function
S Sickle cell anaemia
S
In the primary structure: a single alteration in the amino acid
structure - substitution of valine GTG (non polar) for glutamic
acid GAG (polar) - only in the beta chain - causes the molecule to
pack differently into the red blood cells, causing sickling.
S Thalassemia
S
inherited condition in which reduced production of one of the
globin chains occurs. The unpaired other chain builds up in the
cells, resulting in problems.
Works Cited
S http://www.austincc.edu/emeyerth/tertiary.htm
S http://faculty.stcc.edu/AandP/AP/AP2pages/Units18to20
/blood/hemoglob.htm
S http://www.biotopics.co.uk/as/haemoglobinproteinstructur
e.html