Haptoglobin Mouse Monoclonal Antibody [5-D3]

Function

Haptoglobin (abbreviated as Hp) is the protein that in humans is encoded by the HP gene. In blood plasma, haptoglobin binds with high affinity to free hemoglobin released from erythrocytes, and thereby inhibits its deleterious oxidative activity. Hemoglobin that has been released into the blood plasma by damaged red blood cells has harmful effects. The HP gene encodes a preproprotein that is processed to yield both alpha and beta chains, which subsequently combines as a tetramer to produce haptoglobin. Haptoglobin functions to bind the free plasma hemoglobin, which allows degradative enzymes to gain access to the hemoglobin while at the same time preventing loss of iron through the kidneys and protecting the kidneys from damage by hemoglobin. The cellular receptor target of Hp is the monocyte/macrophage scavenger receptor, CD163. Following Hb-Hp binding to CD163, cellular internalization of the complex leads to globin and heme metabolism, which is followed by adaptive changes in antioxidant and iron metabolism pathways and macrophage phenotype polarization.

Background References

1. Abdullah M & Goldmann T Pulmonary haptoglobin (pHp) is part of the surfactant system in the human lung. Diagn Pathol 7:158 (2012).

2. Tomazic PV et al. Nasal mucus proteomic changes reflect altered immune responses and epithelial permeability in patients with allergic rhinitis. J Allergy Clin Immunol N/A:N/A (2013).

Sequence Similarity

Belongs to the peptidase S1 family.

Tissue Specificity

Expressed by the liver and secreted in plasma.

Subcellular Location

Secreted.

UNIPROT

SwissProt: P00738 Human

Synonyms