Del Mercato Loretta Laureana, Pompa Pier Paolo, Maruccio Giuseppe, Della Torre Antonio, Sabella Stefania, Tamburro Antonio Mario, Cingolani Roberto, Rinaldi Ross
National Nanotechnology Laboratory, Istituto Nazionale per la Fisica della Materia-Consiglio Nazionale della Ricerche, University of Salento, Lecce, Italy.
Proc Natl Acad Sci U S A. 2007 Nov 13;104(46):18019-24. doi: 10.1073/pnas.0702843104. Epub 2007 Nov 5.
The self-assembly of polypeptides into stable, conductive, and intrinsically fluorescent biomolecular nanowires is reported. We have studied the morphology and electrical conduction of fibrils made of an elastin-related polypeptide, poly(ValGlyGlyLeuGly). These amyloid-like nanofibrils, with a diameter ranging from 20 to 250 nm, result from self-assembly in aqueous solution at neutral pH. Their morphological properties and conductivity have been investigated by atomic force microscopy, scanning tunneling microscopy, and two-terminal transport experiments at the micro- and nanoscales. We demonstrate that the nanofibrils can sustain significant electrical conduction in the solid state at ambient conditions and have remarkable stability. We also show intrinsic blue-green fluorescence of the nanofibrils by confocal microscopy analyses. These results indicate that direct (label-free) excitation can be used to investigate the aggregation state or the polymorphism of amyloid-like fibrils (and possibly of other proteinaceous material) and open up interesting perspectives for the use of peptide-based nanowire structures, with tunable physical and chemical properties, for a wide range of nanobiotechnological and bioelectronic applications.
据报道，多肽可自组装成稳定、导电且具有内在荧光的生物分子纳米线。我们研究了由弹性蛋白相关多肽聚（缬氨酸 - 甘氨酸 - 甘氨酸 - 亮氨酸 - 甘氨酸）制成的原纤维的形态和导电性。这些类淀粉样纳米纤维直径在20至250纳米之间，是在中性pH值的水溶液中自组装形成的。通过原子力显微镜、扫描隧道显微镜以及在微米和纳米尺度下的两终端传输实验，对它们的形态特性和导电性进行了研究。我们证明，这些纳米纤维在环境条件下的固态中能够维持显著的导电性，并且具有出色的稳定性。通过共聚焦显微镜分析，我们还展示了纳米纤维的内在蓝绿色荧光。这些结果表明，直接（无标记）激发可用于研究类淀粉样纤维（以及可能的其他蛋白质材料）的聚集状态或多态性，并为具有可调物理和化学性质的基于肽的纳米线结构在广泛的纳米生物技术和生物电子应用中开辟了有趣的前景。
