QUANTITATIVE-EVALUATION OF CONGO RED BINDING TO AMYLOID-LIKE PROTEINS WITH A BETA-PLEATED SHEET CONFORMATION
QUANTITATIVE-EVALUATION OF CONGO RED BINDING TO AMYLOID-LIKE PROTEINS WITH A BETA-PLEATED SHEET CONFORMATION
复制标题
DOI：
10.1177/37.8.2666510
复制
发表时间：
1989-08-01
影响因子：
3.2
通讯作者：
ABRAHAM, DJ
中科院分区：
文献类型：
--
作者：
KLUNK, WE;PETTEGREW, JW;ABRAHAM, DJ
定量检测了刚果红与几种纯化的具有β-折叠片构象的淀粉样肽的结合。刚果红优先结合胰岛素原纤维和聚-L-赖氨酸的β-折叠片构象。刚果红与聚-L-丝氨酸或聚甘氨酸的结合几乎没有那么好，尽管这些肽也具有β-折叠片构象。与胰岛素原纤维的结合是可饱和的，表观Bmax为每摩尔胰岛素原纤维2摩尔刚果红，表观KD为1.75 × 10 - 6。10-7 M.与β-聚-L-赖氨酸的结合相似，但具有高得多的表观Bmax，为43。刚果红与β-聚-L-赖氨酸的结合是pH依赖性的，并且似乎是由250个氨基酸肽中质子化赖氨酸残基的数量决定的。我们提出了一个新的假设，其中刚果红通过刚果红的两个带负电荷的磺酸基团和两个独立的蛋白质分子的两个带正电荷的氨基酸残基之间的键结合到淀粉样蛋白，所述两个独立的蛋白质分子通过肽骨架的β-折叠构象而适当地定向。
The binding of Congo red to several purified amyloid-like peptides having a beta-pleated sheet conformation was quantitatively examined. Congo red binds preferentially to the beta-pleated sheet conformation of both insulin fibrils and poly-L-lysine. Congo red does not bind nearly so well to poly-L-serine or polyglycine, despite the fact that these peptides also have a beta-pleated sheet conformation. Binding to insulin fibrils was saturable with an apparent Bmax of 2 moles of Congo red per mole of insulin fibrils and an apparent KD of 1.75 .times. 10-7 M. Binding to beta-poly-L-lysine was similar but had a much higher apparent Bmax of 43. Binding of Congo red to beta-poly-L-lysine was pH dependent and appeared to be determined by the number of protonated lysine residues in the 250 amino acid peptide. We present a new hypothesis in which Congo red binds to amyloid-like proteins via bonds between the two negatively charged sulfonic acid groups of Congo red and two positively charged amino acid residues of two separate protein molecules which are properly oriented by virtue of the beta-pleted sheet conformation of the peptide backbone.