Lapolla A, Fedele D, Traldi P
Università di Padova, Dipartimento di Scienze Mediche e Chirurgiche, Padova, Italy.
Mass Spectrom Rev. 2000 Sep-Oct;19(5):279-304. doi: 10.1002/1098-2787(2000)19:5<279::AID-MAS3>3.0.CO;2-G.
Mass spectrometry has been applied successfully to the study of non-enzymatic protein glycation, which is a topic of wide interest in the diabetes field. Low- and high-resolution mass spectra, GC/MS, and collisional activation spectroscopy allow the structural identification and quantitative evaluation of advanced glycation end-products, which represent important molecules for monitoring diabetes. More recently available techniques, such as ESI and MALDI/MS, have had a significant impact on analytical problems in diabetes. In particular, MALDI has been applied to the study of protein glycation in in vitro and in vivo conditions, because the number of glucose molecules that condense onto the protein can be easily determined by this approach. In the former case, glycation kinetics have been studied in various sugars and sugar concentrations, proteins, and buffer concentrations; in the latter, comparisons of MALDI spectra of circulating proteins from healthy and diabetic subjects determine the exposure of patients to high glucose levels. The method has been applied to an evaluation of the glycation level of immunoglobulins, and indicates that glycation takes place preferentially on the Fab fragment of the protein; data are relevant in relating immunological impairment with glycation-induced changes in the functionality of immunoglobulins.
质谱分析法已成功应用于非酶蛋白糖基化的研究，这是糖尿病领域广泛关注的一个话题。低分辨率和高分辨率质谱、气相色谱/质谱联用以及碰撞活化光谱法能够对晚期糖基化终产物进行结构鉴定和定量评估，而这些终产物是监测糖尿病的重要分子。最近出现的技术，如电喷雾电离和基质辅助激光解吸/电离质谱联用，对糖尿病的分析问题产生了重大影响。特别是，基质辅助激光解吸/电离已应用于体外和体内条件下蛋白质糖基化的研究，因为通过这种方法可以轻松确定凝结在蛋白质上的葡萄糖分子数量。在前一种情况下，已在各种糖类、糖浓度、蛋白质和缓冲液浓度条件下研究了糖基化动力学；在后一种情况下，通过比较健康受试者和糖尿病患者循环蛋白的基质辅助激光解吸/电离光谱，可确定患者对高血糖水平的暴露情况。该方法已用于评估免疫球蛋白的糖基化水平，并表明糖基化优先发生在蛋白质的Fab片段上；这些数据对于将免疫损伤与糖基化诱导的免疫球蛋白功能变化联系起来具有重要意义。
