An acute-phase plasma protein found in human plasma at 100-300 mg per 100 ml. Binds hemoglobin, thus preventing loss of iron through the kidneys. Humans are polymorphic for haptoglobin, with three major phenotypes: Hp 1-1, Hp 2-1, and Hp 2-2. While the phenotypic distribution can vary greatly between ethnicities and geographic location, the Hp 2-1 phenotype is the most prevalent phenotype in humans. Plasma concentrations of haptoglobin are highest in individuals with Hp 1-1, intermediate in Hp 2-1 individuals, and lowest in Hp 2-2 individuals. Hp 1-1 is the most effective at binding hemoglobin, and Hp 2-2 is the least effective. This functional difference may be associated with the frequency and severity of epilepsy attacks, as researchers have found a correlation between recurring seizures and the Hp 2-2 phenotype. Product Citations: Shimazaki, Youji, and Madoka Michhiro. "Analysis of trypsin inhibition activity in human plasma proteins after separation by non-denaturing two-dimensional electrophoresis." Clinica Chimica Acta (2013). Gunasena, Dilani N., and Ziad El Rassi. "Hydrophilic diol monolith for the preparation of immuno‐sorbents at reduced nonspecific interactions."Journal of separation science 34.16‐17 (2011): 2097-2105. Sakamoto K, et al. IL-22 Controls Iron-Dependent Nutritional Immunity Against Systemic Bacterial Infections. Sci Immunol. 2017 Feb;2(8). pii: eaai8371. doi: 10.1126/sciimmunol.aai8371. Epub 2017 Feb 3. Kozlik P, Goldman R, Sanda M. Study of structure-dependent chromatographic behavior of glycopeptides using reversed phase nanoLC. Electrophoresis. 2017 Apr 26. doi: 10.1002/elps.201600547. [Epub ahead of print]. Eshbach ML, et al. Hemoglobin inhibits albumin uptake by proximal tubule cells: implications for sickle cell disease. Am J Physiol Cell Physiol. 2017 Jun 1;312(6):C733-C740. doi: 10.1152/ajpcell.00021.2017. Epub 2017 Mar 29.
