Faculty of Chemistry, University of Wrocław, 50-137 Wrocław, Poland.
Anal Biochem. 2010 May 15;400(2):237-43. doi: 10.1016/j.ab.2010.02.011. Epub 2010 Feb 13.
The products of nonenzymatic glycation of proteins are formed in a chemical reaction between reducing sugars and the free amino group located either at the N terminus of the polypeptide chain or in the lysine side chain. Glycated proteins and their fragments could be used as markers of the aging process as well as diabetes mellitus and Alzheimer's disease, making them an object of interest in clinical chemistry. In this article, we propose a new method for the identification of peptide-derived Amadori products in the mixtures obtained by enzymatic hydrolysis of glycated proteins. Two proteins, ubiquitin and human serum albumin (HSA), were modified with an equimolar mixture of glucose and [(13)C(6)]glucose and were subjected to enzymatic hydrolysis. The obtained enzymatic digests were analyzed by high-resolution mass spectrometry (HRMS), and the peptide-derived Amadori products were identified on the basis of specific isotopic patterns resulting from (13)C substitution. The number of glycated peptides in the digest of HSA detected by our procedure was in agreement with the data recently reported in the literature.
蛋白质的非酶糖化产物是还原糖与多肽链 N 末端或赖氨酸侧链上的游离氨基之间的化学反应形成的。糖化蛋白及其片段可作为衰老过程以及糖尿病和阿尔茨海默病的标志物，这使得它们成为临床化学研究的对象。在本文中，我们提出了一种新的方法，用于鉴定通过糖化蛋白酶解获得的混合物中的肽衍生的麦拉德产物。两种蛋白质，泛素和人血清白蛋白（HSA），与等摩尔葡萄糖和[(13)C(6)]葡萄糖混合物进行修饰，并进行酶水解。通过高分辨率质谱（HRMS）分析获得的酶解产物，并根据（13）C 取代产生的特定同位素模式鉴定肽衍生的麦拉德产物。我们的方法检测到的 HSA 酶解产物中的糖化肽数量与最近文献中报道的数据一致。
