|
| Function | No difference between Hp types | Difference between Hp types |
|
| Hp expression | | Serum Hp1-1 higher than Hp2-2, with Hp2-1 intermediate, in many populations tested, including European (Belgian [37–39], Iceland [40]), East Asian (Japanese [41], Koreans [42]), and African (Black Zimbabweans [43], Gabonese [44], Papuans [45]) |
| Haemoglobin binding: capacity per Hp monomer | (1) Ultrafiltration assay of uncomplexed Hb [46]
(2) Mass spectrometry [24] | |
| Haemoglobin binding: affinity | (1) Surface plasmon resonance [47]
(2) Surface plasmon resonance [24]
(3) Spectrophotometric signal of Hp-Hp interaction [48] | |
| Inhibition of Hb-mediated oxidation | (1) Reduction in low density lipoprotein oxidation [24]
(2) Reduction in Hb intrinsic redox potential [48]
(3) Reduction in Hb auto-oxidation [17] | (1) Hp1-1 better than Hp2-2 at inhibiting protein and lipid oxidation [49]
(2) Hp1-1 better than Hp2-2 at inhibiting oxidation of linolenic acid and low-density lipoprotein [46]
(3) Hp1-1 better than Hp2-2 at inhibiting lipid peroxidation [47] |
| Interaction with CD163: affinity | | (1) Hp2-2 better than Hp1-1, by surface plasmon resonance and binding of radioiodinated Hp-Hb complexes in vitro [1]
(2) Hp2-2 better than Hp1-1, by binding of radio-iodinated Hp-Hb complexes in vitro [50] |
| Interaction with CD163: uptake of Hp-Hb complexes | Plasma half-life of Hp-Hb complexes after injection in guinea pigs [24] | (1) Hp2-2 better than Hp1-1, by measurement of free Hb in humans [51]
(2) Hp1-1 better than Hp2-2, by uptake of radio-iodinated Hp-Hb complexes in human cells in vitro [50] |
| Effects on inflammation | | Binding of Hp1-1-Hb complexes to CD163 results in secretion of the anti-inflammatory cytokine IL-10 [19, 20] |
|
