Haptoglobin was used to study induction of the acrosome reaction in sperm. Exposure to low temperature increases their rate of fusion with zona-free hamster oocytes.
Haptoglobin is an α2-globulin found in normal plasma at a concentration of 82-236 mg/dl and accounts for 0.4-2.6% of the total plasma proteins.The monomeric form of this acute phase plasma protein is composed of four polypeptide chains: two α chains and two β chains.
Functions by binding to plasma hemoglobin (from hemolysis). The complex is removed from the circulation, by binding to CD163 receptors on macrophages, to salvage iron and prevent oxidative damage.
