Recombinant Mouse Haptoglobin Protein Standard (His tag)

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Haptoglobin (Hp) also known as Hp protein is a glycoprotein with a molecular weight ranging from 85 to 100 kDa varying due to its ability to form different dimeric and multimeric structures. It is primarily synthesized in the liver and circulating in the plasma. Mechanically haptoglobin binds free hemoglobin released from erythrocytes preventing oxidative damage and hemoglobin-driven deleterious effects. Haptoglobin's binding to hemoglobin forms a haptoglobin-hemoglobin complex that gets cleared by the CD163 receptor on macrophages mainly in the liver and spleen.

Biological function summary

Haptoglobin functions as an antioxidant and an acute phase protein playing roles in inflammation and immune response. It is an essential component of the antioxidant defense system reducing oxidative stress by binding free hemoglobin. Additionally haptoglobin can participate in complex formation with hemoglobin to facilitate the clearance of excess free hemoglobin from circulation. Its expression increases during inflammation under the regulation of cytokines like IL-6.

Pathways

The haptoglobin protein is part of the hemoglobin clearance pathway integral for iron metabolism and homeostasis. This pathway ensures the safe removal of hemoglobin from the blood helping to prevent kidney damage. Haptoglobin is related to other proteins such as CD163 and the liver-derived hepatocellular proteins involved in the clearance process. Also haptoglobin is linked to antioxidant pathways collaborating with oxidative stress regulators to manage reactive oxygen species levels.

Changes in haptoglobin levels are associated with hemolytic anemia and inflammatory conditions. Low haptoglobin levels often suggest hemolytic anemia due to its rapid binding with free hemoglobin in the bloodstream. During inflammation and infections 'anti-Hp' tests (haptoglobin tests) may show increased haptoglobin levels as a response to cytokine signaling. Moreover haptoglobin polymorphisms have a connection with ischemic stroke susceptibility where its isoforms show differing efficiencies in binding free hemoglobin. These findings highlight haptoglobin's relevance as a biomarker for these conditions and illustrate its interaction with hematologic and immune proteins in disease contexts.