Study Set Content:
hydrogen bonds
hydrophobic interactions
• The quaternary structure found in some proteins results from interactions between two or more
polypeptide chains
The quaternary structure found in some proteins results from interactions between two or more polypeptide chains — interactions that are usually the same as those that give rise to the
tertiary structure
These interactions include
hydrogen bonding and disulfide bonds
This quaternary structure locks the complex of proteins into a
specific geometry.
has four polypeptide chains
hemoglobin
here are two identical
α-chains
and two identical
β- chains
is found primarily in skeletal and striated muscle which mainly serves as a store of O2 in the cytoplasm and deliver it on demand to the mitochondria.
Myoglobin (Mb)
) is restricted to the erythrocytes which is responsible for the movement of O2 between lungs and other tissues
Hemoglobin (Hb)
is the prosthetic group found in Mb and Hb
Heme
Iron +
protoporphyrin IX
Oxygen-binding molecule
Heme
Gives globin proteins their characteristic
red-brown color
primary structure 153 amino acids
Myoglobin
Secondary structure Eight alpha-helixes
Myoglobin
primary structure 141 alpha-chain and 146 beta-chain amino acids
Hemoglobin
Secondary structure Eight alpha-helixes for each alpha-chain and beta-chain
Hemoglobin
Tertiary structure Folding of alpha-helixes
Hemoglobin
