Development of a method for early diagnosis of diabetic of complications by detecting glycation reaction intermediates.

糖基化发生在正常衰老过程中，糖尿病患者的糖基化速度加快，并与蛋白质和其他细胞成分的结构和功能改变有关。在糖尿病并发症方面，糖基化假说和多元醇途径假说通常是独立讨论的。通过免疫果氨酸赖氨酸偶联卵清蛋白，制备了一种针对蛋白中果氨酸赖氨酸的抗体。亲和纯化抗体特异性识别与果糖孵育的蛋白质，而不识别与葡萄糖孵育的蛋白质。当牛血清白蛋白与不同浓度的果糖孵育时，三种抗体的反应性呈剂量和时间依赖性增加。当使用该抗体对正常或链脲佐菌素诱导的糖尿病大鼠眼睛制备的可溶性蛋白进行ELISA分析时，观察到活性成分的增加是衰老和糖尿病条件下的功能。免疫印迹分析显示，晶状体结晶蛋白与该抗体反应强烈。由于果糖主要是通过多元醇途径进行生物合成的，而多元醇途径在糖尿病条件下被增强，并且已知晶状体具有该途径的高活性，因此该抗体能够在体内识别果糖化蛋白。因此，该抗体代表了一个潜在的有用工具，用于研究糖尿病并发症的两个主要问题，即糖基化反应和多元醇途径。

Glycation occurs during normal aging and at accelerated rates in diabetes and is involved in structural and functional alterations of proteins and other cellular components. In terms of diabetic complications, the glycation hypothesis and the poiyol pathway hypothesis are usually discussed independently. An antibody was raised against fructated lysine in proteins by immunizing fructated lysine-conjugated ovalbumin in rabbits. The affinity purified antibody specifically recognized proteins incubated with fructose, but not with glucose. When bovine serum albumin was incubated with various concentrations of fructose, the reactivity of thee antibody increased in a dose- and time-dependent manner. When soluble proteins prepared from either normal or streptozotocin-induced diabetic rat eyes were analyzed by ELISA using this antibody, an increase in the reactive components was observed as a function of aging as well as under diabetic conditions. Immunoblot analysis showed that lens crystallin reacted highly with this antibody. Since fructose is largely biosynthesized through the polyol pathway, which is enhanced under diabetic conditions and lens is known to have a high activity of this pathway, this antibody is capable of recognizing fructated proteins in viva. Thus this antibody represents a potentially useful tool for investigating two major issues which appear to be involved in diabetic complications, namely, the glycation reaction and the polyol pathway.