Borbas K Eszter, Mroz Pawel, Hamblin Michael R, Lindsey Jonathan S
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA.
Bioconjug Chem. 2006 May-Jun;17(3):638-53. doi: 10.1021/bc050337w.
A broad range of applications requires access to water-soluble, bioconjugatable porphyrins. Branched alkyl groups attached at the branching site to the porphyrin meso position are known to impart high organic solubility. Such "swallowtail" motifs bearing a polar group (hydroxy, dihydroxyphosphoryl, dihydroxyphosphoryloxy) at the terminus of each branch have now been incorporated at a meso site in trans-AB-porphyrins. The incorporation of the swallowtail motif relies on rational synthetic methods whereby a 1,9-bis(N-propylimino)dipyrromethane (bearing a bioconjugatable tether at the 5-position) is condensed with a dipyrromethane (bearing a protected 1,5-dihydroxypent-3-yl unit at the 5-position). The two hydroxy groups in the swallowtail motif of each of the resulting zinc porphyrins can be transformed to the corresponding diphosphate or diphosphonate product. A 4-(carboxymethyloxy)phenyl group provides the bioconjugatable tether. The six such porphyrins reported here are highly water-soluble (> or =20 mM at room temperature in water at pH 7) as determined by visual inspection, UV-vis absorption spectroscopy, or 1H NMR spectroscopy. Covalent attachment was carried out in aqueous solution with the unprotected porphyrin diphosphonate and a monoclonal antibody against the T-cell receptor CD3epsilon. The resulting conjugate performed comparably to a commercially available fluorescein isothiocyanate-labeled antibody with Jurkat cells in flow cytometry and fluorescence microscopy assays. Taken together, this work enables preparation of useful quantities of water-soluble, bioconjugatable porphyrins in a compact architecture for applications in the life sciences.
广泛的应用需要使用水溶性、可生物共轭的卟啉。已知连接在卟啉中位位置分支点处的支链烷基可赋予高有机溶解度。现在，在反式AB-卟啉的中位位置引入了这种在每个分支末端带有极性基团（羟基、二羟基磷酰基、二羟基磷酰氧基）的“燕尾”基序。燕尾基序的引入依赖于合理的合成方法，即1,9-双（N-丙基亚氨基）二吡咯甲烷（在5位带有可生物共轭的连接链）与二吡咯甲烷（在5位带有受保护的1,5-二羟基戊-3-基单元）缩合。所得锌卟啉中每个的燕尾基序中的两个羟基可转化为相应的二磷酸酯或二膦酸酯产物。4-（羧甲基氧基）苯基提供可生物共轭的连接链。通过目视检查、紫外可见吸收光谱或1H NMR光谱测定，此处报道的六种此类卟啉具有高水溶性（室温下在pH 7的水中≥20 mM）。在水溶液中用未保护的卟啉二膦酸酯和抗T细胞受体CD3ε单克隆抗体进行共价连接。在流式细胞术和荧光显微镜分析中，所得共轭物与市售异硫氰酸荧光素标记的抗体在Jurkat细胞上的表现相当。综上所述，这项工作能够以紧凑的结构制备有用量的水溶性、可生物共轭的卟啉，用于生命科学应用。
