Dolhofer-Bliesener R, Lechner B, Gerbitz K D
Institut für Klinische Chemie, Akademisches Lehrkrankenhaus, Universität München, Germany.
Eur J Clin Chem Clin Biochem. 1994 May;32(5):329-36. doi: 10.1515/cclm.1994.32.5.329.
Glycation and fluorescence at 440 nm (excitation at 370 nm) were found to be increased in immunoglobulin G (IgG) from diabetics, strongly indicating the presence of IgG-linked advanced glycosylation end products. In contrast, levels of IgG-linked advanced glycosylation end products were low or undetectable in both normal and diabetic subjects when an advanced glycosylation end products specific antibody was employed for immunological determination of advanced glycosylation end products. Furthermore, no correlation exists between IgG glycation, fluorescence and immunoreactivity. In diabetics, the Fc fragment of IgG showed decreased protein A binding and decreased fixation of complement. This impairment of biological activity was not correlated with the immunologically determined level of advanced glycosylation end products, whereas IgG-linked fluorescence was inversely related to complement fixing activity. These results indicate that mechanisms different from glycation or browning are responsible for changes in the functional properties of IgG.
研究发现，糖尿病患者免疫球蛋白G（IgG）的糖基化以及在440nm处的荧光（370nm激发）有所增加，这有力地表明存在与IgG相关的晚期糖基化终产物。相比之下，当使用晚期糖基化终产物特异性抗体对晚期糖基化终产物进行免疫学测定时，正常人和糖尿病患者体内与IgG相关的晚期糖基化终产物水平均较低或无法检测到。此外，IgG糖基化、荧光和免疫反应性之间不存在相关性。在糖尿病患者中，IgG的Fc片段显示出与蛋白A结合减少以及补体固定减少。这种生物活性的损害与免疫学测定的晚期糖基化终产物水平无关，而与IgG相关的荧光与补体固定活性呈负相关。这些结果表明，与糖基化或褐变不同的机制导致了IgG功能特性的变化。
