The applicability of capillary zone electrophoresis (CZE) for the separation of the deamidated forms of insulin has been studied. 50 mM NH₄Ac (pH=9) with 20 % v/v isopropylalcohol was found optimal for efficient separation of insulin from its even 10 deamidated forms. The developed method was efficiently applied for monitoring the degradation rate of insulin and the formation of different deamidation isoforms. Two months after the acidification more than thirty peaks can be observed in the electropherogram, because degradation products other than deamidated components were formed as well. The recorded mass spectra enabled us to assign the exact mass of the components, and thus the identification of insulin isoforms could be accomplished. We think that this study provides useful information on how the determination of several deamidation forms can be carried out with CE-MS, but the identification of the exact position of deamidation sites in the insulin molecule remains a challenge.

研究了毛细管区带电泳（CZE）在分离脱酰胺形式的胰岛素中的适用性。50毫米NH ₄发现含有20％v / v异丙醇的Ac（pH = 9）最适合从10种脱酰胺形式中有效分离胰岛素。所开发的方法有效地用于监测胰岛素的降解速率和不同的脱酰胺亚型的形成。酸化两个月后，在电泳图中可观察到30个以上的峰，因为还形成了除脱酰胺基成分以外的降解产物。记录的质谱图使我们能够分配组分的确切质量，因此可以完成胰岛素同工型的鉴定。我们认为这项研究提供了有关如何使用CE-MS确定几种脱酰胺形式的有用信息，但是如何确定脱酰胺位在胰岛素分子中的确切位置仍然是一个挑战。