Beccaria L, Chiumello G, Gianazza E, Luppis B, Righetti P G
Am J Hematol. 1978;4(4):367-74. doi: 10.1002/ajh.2830040408.
A modified type of isolectric focusing has been applied successfully to the separation of hemoglobin A1C (HbA1C) from HbA in normal and diabetic cell lysates. It consists of transforming a linear pH gradient into a nonlinear one, by the addition of an amphoteric substance ("separator" or "pH gradient modifier") with an isoelectric point (pI) close to the pI's of the two hemoglobins. Among the "modifiers" tested, histidine, proline, threonine, beta-alanine, 6-amino caproic acid, and 5-amino valeric acid are not useful in the hemoglobin pI range (pH 6.9--7.0). The dipeptide histidyl-glycine (pI = 6.8; pI-pK1 = 1) is very efficient in flattening the pH gradient, in the hemoglobin region. even when added in low concentrations (10--100 mM), thus affording full resolution of the two hemoglobin species.
一种改良型的等电聚焦法已成功应用于从正常细胞裂解液和糖尿病细胞裂解液中的血红蛋白A（HbA）中分离出血红蛋白A1C（HbA1C）。它包括通过添加一种等电点（pI）接近两种血红蛋白pI的两性物质（“分隔剂”或“pH梯度调节剂”），将线性pH梯度转变为非线性pH梯度。在所测试的“调节剂”中，组氨酸、脯氨酸、苏氨酸、β-丙氨酸、6-氨基己酸和5-氨基戊酸在血红蛋白pI范围（pH 6.9 - 7.0）内没有作用。二肽组氨酰甘氨酸（pI = 6.8；pI - pK1 = 1）在血红蛋白区域使pH梯度变平缓方面非常有效，即使以低浓度（10 - 100 mM）添加，也能实现两种血红蛋白的完全分离。
