Department of Chemistry and Applied Biosciences, Institute of Pharmaceutical Sciences, and Philochem AG, ETH Zurich, Wolfgang-Pauli-Str. 10, CH-8093 Zurich, Switzerland.
Bioconjug Chem. 2009 Dec;20(12):2286-92. doi: 10.1021/bc9002772.
Antibody fragments can recognize their cognate antigen with high affinity and can be produced at high yields, but generally display rapid blood clearance profiles. For pharmaceutical applications, the serum half-life of antibody fragments is often extended by chemical modification with polymers or by genetic fusion to albumin or albumin-binding polypeptides. Here, we report that the site-specific chemical modification of a C-terminal cysteine residue in scFv antibody fragments with a small organic molecule capable of high-affinity binding to serum albumin substantially extends serum half-life in rodents. The strategy was implemented using the antibody fragment F8, specific to the alternatively spliced EDA domain of fibronectin, a tumor-associated antigen. The unmodified and chemically modified scFv-F8 antibody fragments were studied by biodistribution analysis in tumor-bearing mice, exhibiting a dramatic increase in tumor uptake for the albumin-binding antibody derivative. The data presented in this paper indicate that the chemical modification of the antibody fragment with the 2-(3-maleimidopropanamido)-6-(4-(4-iodophenyl)butanamido)hexanoate albumin-binding moiety may represent a general strategy for the extension of the serum half-life of antibody fragments and for the improvement of their in vivo targeting performance.
抗体片段可以高亲和力识别其同源抗原，并且可以高产率产生，但通常显示快速的血液清除谱。对于药物应用，通过与聚合物的化学修饰或通过与白蛋白或白蛋白结合多肽的遗传融合，抗体片段的血清半衰期通常会延长。在这里，我们报告了通过能够与血清白蛋白高亲和力结合的小分子对 scFv 抗体片段的 C 末端半胱氨酸残基进行定点化学修饰，可显著延长啮齿动物的血清半衰期。该策略使用针对纤连蛋白的交替剪接 EDA 结构域的抗体片段 F8 实施，纤连蛋白是一种肿瘤相关抗原。在荷瘤小鼠中通过生物分布分析研究了未修饰和化学修饰的 scFv-F8 抗体片段，对于白蛋白结合抗体衍生物，肿瘤摄取明显增加。本文介绍的数据表明，用 2-(3-马来酰亚胺丙酰胺基)-6-(4-(4-碘苯基)丁酰胺基)己酸白蛋白结合部分对抗体片段进行化学修饰可能代表延长抗体片段血清半衰期和改善其体内靶向性能的通用策略。
