Krantz S, Brandt R, Gromoll B
Institut für Biochemie, Ernst-Moritz-Arndt-Universität, Greifswald, Germany.
Biochim Biophys Acta. 1993 May 8;1177(1):15-24. doi: 10.1016/0167-4889(93)90151-e.
The interaction of in vitro short-term glycated rat serum albumin with rat peritoneal cells (40% macrophages) was investigated. Using 125I-labeled albumins the following results were obtained. Glycated albumins showed a binding reaction at 4 degrees C, which appeared to reach equilibrium within 2 h. The concentration-dependent binding of glycated albumin showed saturation. Binding data evaluated for glycated albumin using the Sips equation are: average association constant Ko = 3.15 x 10(7) M-1 with a heterogeneity index of a = 0.8 and 1.12 x 10(4) binding sites per cell. Such binding sites were identified in 40% of the peritoneal cell preparations studied. Native albumins, maleylated albumin, chondroitinsulfates, polylysine, lysine, fructose, glucose and hexitol-lysine could not compete with radio-labeled glycated rat albumin for its binding site on peritoneal cells. Effective competitors were glycated human serum albumin, glycated polylysine and fructose-lysine. Although the contamination with minute amounts of advanced glycosylation end products (AGE) could not be excluded, short-term glycated albumin was found to be bound to membranes of peritoneal phagocytotic cells by fructose-lysine specific proteins, whose approximately defined molecular masses of 290 kDa are distinct from hitherto described binding proteins for AGE- and aldehyde-modified proteins or for the scavenger receptors.
研究了体外短期糖化大鼠血清白蛋白与大鼠腹膜细胞（40%为巨噬细胞）的相互作用。使用125I标记的白蛋白得到了以下结果。糖化白蛋白在4℃时表现出结合反应，该反应在2小时内似乎达到平衡。糖化白蛋白的浓度依赖性结合表现出饱和性。使用Sips方程评估的糖化白蛋白结合数据为：平均缔合常数Ko = 3.15×10(7) M-1，异质性指数a = 0.8，每个细胞有1.12×10(4)个结合位点。在所研究的40%的腹膜细胞制剂中鉴定出了此类结合位点。天然白蛋白、马来酰化白蛋白、硫酸软骨素、聚赖氨酸、赖氨酸、果糖、葡萄糖和己糖醇赖氨酸不能与放射性标记的糖化大鼠白蛋白竞争其在腹膜细胞上的结合位点。有效的竞争者是糖化人血清白蛋白、糖化聚赖氨酸和果糖赖氨酸。尽管不能排除微量晚期糖基化终产物（AGE）的污染，但发现短期糖化白蛋白通过果糖赖氨酸特异性蛋白与腹膜吞噬细胞的膜结合，其大约确定的分子量为290 kDa，与迄今描述的AGE和醛修饰蛋白或清道夫受体的结合蛋白不同。
