Department of Human Protein Sciences, University Medical Centre, University of Geneva, Geneva, Switzerland.
Anal Chem. 2011 Jul 15;83(14):5673-80. doi: 10.1021/ac200864b. Epub 2011 Jun 23.
Despite continuous advances in hyperglycemia treatments, a precise control through monitoring of glucose and glycated hemoglobin remains in most diabetic patients as the diagnosis/prognosis tool. An alternative perspective could be the discovery and quantitation of new blood glycated proteins formed by nonenzymatic reaction with circulatory glucose. As a result, the human hemolysate is an incomparable source of glycated proteins to further monitor glycemia and interpret changes at the level of this post-translational modification. The human hemolysate is here studied based on the differential labeling of proteins with isotopically labeled-glucose ([(13)C(6)] glucose), named glycation isotopic labeling. Due to the chemoselectivity of glycation, only preferential targets are labeled by this protocol. The approach provides qualitative data through the detection of preferential protein glycation sites as well as quantitative information to evaluate the abundance of this modification. This strategy was applied to human hemolysate samples corresponding to different glycemic states estimated by laboratory-certified concentrations of glycated hemoglobin. The glycation level of each protein can then be employed to interpret the effect of glucose exposition as a consequence of glycemic unbalance. This information should provide new molecular insights into protein glycation mechanisms that might generate a new hypothesis to clinicians to improve the understanding of underlying pathologies associated to prolonged hyperglycemia.
尽管在高血糖治疗方面不断取得进展，但在大多数糖尿病患者中，通过监测血糖和糖化血红蛋白来精确控制血糖仍然是诊断/预后的工具。另一种观点可以是发现和定量由循环葡萄糖与非酶反应形成的新的糖化血液蛋白。因此，人血红细胞裂解物是监测血糖和解释这种翻译后修饰水平变化的无与伦比的糖化蛋白来源。在此，基于用同位素标记的葡萄糖（[(13)C(6)] 葡萄糖）对蛋白质进行差异标记，即糖化同位素标记，对人血红细胞裂解物进行了研究。由于糖化的化学选择性，只有优先的靶标被该方案标记。该方法通过检测优先的蛋白质糖化位点提供定性数据，以及通过评估这种修饰的丰度来提供定量信息。该策略应用于人血红细胞裂解物样品，这些样品对应于通过实验室认证的糖化血红蛋白浓度估计的不同血糖状态。然后，可以将每个蛋白质的糖化水平用于解释葡萄糖暴露对血糖失衡的影响。这些信息应该为蛋白质糖化机制提供新的分子见解，这可能为临床医生提供一个新的假设，以提高对与长期高血糖相关的潜在病理的理解。
