Haptoglobin properties

As mentioned above, the name haptoglobin was coined to designate plasma components forming stable Hb complexes in which the Hb has acquired the properties of peroxidase. To describe an unidentified substance simply by the properties of its complexes with only one other substance is unsatisfactory. Hp as well as Hb from different species will presumably vary to some extent in composition, in the stability of their complexes, and in their peroxidase properties. Thus dog Hp, for example, links human or dog Hb, but the latter Hb complex shows only weak peroxidase activity in Jayle s conventional peroxidase test (N5). 

The vague definition offered above or rather these characteristics appear to be sufficient since no plasma protein capable of forming a strong bond with Hb is known to occur in mammalian plasma except those mucoproteins with the general biochemical properties originally accepted as characteristic of haptoglobins. 

L8. Laurell, C.-B., Purification and properties of different haptoglobins. Clin. Chim. Acta 4, 79 (1959). 

Purification of oestradiol receptor of calf uterus by affinity chromatography Purification of collagenase by affinity chromatography isolation of anti-haptoglobin antibodies by immunoadsorption Removal of interspecies reactivity from anti-(immunoglobulin G) sera (human or rabbit) Investigation of the properties of the immobilized IgG... 

Fraser et al (1972) showed 25 years ago that addition of various serum proteins to hyaluronan substantially increased the viscosity and this has received a renewed interest in view of recently discovered hyaladherins (see above). The TSG-6 and inter-a-trypsin inhibitor and other acute phase reactants such as haptoglobin are concentrated to arthritic synovial fluid [52], It is not known to what extent these are affecting the rheology and lubricating properties. 

Starch gel with certain properties gives excellent separation of blood serum proteins, revealing genetic differences in haptoglobins, siderophilins. etc. This separation may be partly due to sorption phenomena. 

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