Purity: > 90% by SDS - PAGE Format: Liquid. In Phosphate Buffered Saline (pH 7.4) containing 10% glycerol.. HP, also known as haptoglobin isoform 2, is consists of two alpha and two beta chains, connected by disulfide bridges in its simplest form. The chains originate from a common precursor protein, which is proteolytically cleaved during protein synthesis. In blood plasma, this protein binds free hemoglobin released from erythrocytes with high affinity and thereby inhibits its oxidative activity. The haptoglobin-hemoglobin complex will then be removed by the reticuloendothelial system (mostly the spleen). It functions to bind 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. For this reason, it is often referred to as the suicide protein. Recombinant human HP, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.