Department of Radiology, The Methodist Hospital Research Institute, 6565 Fannin Street, B5-022, Houston, Texas 77030, USA.
Bioconjug Chem. 2010 Feb 17;21(2):270-8. doi: 10.1021/bc900313d.
Computer modeling approaches to identify new inhibitors are essentially a very sophisticated and efficient way to design drugs. In this study, a bivalent nonpeptide intergrin alpha(v)beta(3) antagonist (bivalent IA) has been synthesized on the basis of an in silico rational design approach. A near-infrared (NIR) fluorescent imaging probe has been developed from this bivalent compound. In vitro binding assays have shown that the bivalent IA (IC(50) = 0.40 +/- 0.11 nM) exhibited improved integrin alpha(v)beta(3) affinity in comparison with the monovalent IA (IC(50) = 22.33 +/- 4.51 nM), resulting in an over 50-fold improvement in receptor affinity. NIR imaging probe, bivalent-IA-Cy5.5 conjugate, also demonstrated significantly increased binding affinity (IC(50) = 0.13 +/- 0.02 nM). Fluorescence microscopy studies showed integrin-mediated endocytosis of bivalent-IA-Cy5.5 in U87 cells which was effectively blocked by nonfluorescent bivalent IA. We also demonstrated tumor accumulation of this NIR imaging probe in U87 mouse xenografts.
计算机建模方法识别新的抑制剂在本质上是一种非常复杂和高效的药物设计方法。在这项研究中，基于计算机模拟的合理设计方法，合成了一种双价非肽整合素 α(v)β(3)拮抗剂（双价 IA）。从这种双价化合物中开发出了一种近红外（NIR）荧光成像探针。体外结合实验表明，与单价 IA（IC（50）= 22.33 +/- 4.51 nM）相比，双价 IA（IC（50）= 0.40 +/- 0.11 nM）表现出改善的整合素 α(v)β(3)亲和力，导致受体亲和力提高了 50 多倍。NIR 成像探针，双价-IA-Cy5.5 缀合物，也表现出显著增加的结合亲和力（IC（50）= 0.13 +/- 0.02 nM）。荧光显微镜研究表明，U87 细胞中双价-IA-Cy5.5 通过整合素介导的内吞作用，而非荧光双价 IA 可有效阻断该作用。我们还证明了这种 NIR 成像探针在 U87 小鼠异种移植瘤中的肿瘤积累。
