摘要:
Receptor-specific proteins produced by genetic engineering are attractive as PET imaging agents, but labeling with conventional F-18-based prosthetic groups is problematic due to long synthesis times, poor radiochemical yields, and low specific activities. Therefore, we developed a modular platform for the rapid preparation of water-soluble prosthetic groups capable of efficiently introducing F-18 into proteins. The utility of this platform is demonstrated by the thiol-specific prosthetic group, [F-18]FPEGMA, which was used to produce site-specifically F-18-labeled protein (F-18-trastuzumab-ThioFab) in 82 min with a total radiochemical yield of 13 +/- 3% and a specific activity of 2.2 +/- 0.2 Ci/mu mol. F-18-trastuzumab-ThioFab retained the biological activity of native protein and was successfully validated in vivo with microPET imaging of Her2 expression in a xenograft tumor-bearing murine model modulated by. the Hsp90 inhibitor, 17-(allylamino)-17-demethoxygeldanamycin.