Maity Indrajit, Manna Manoj K, Rasale Dnyaneshwar B, Das Apurba K
Department of Chemistry, Indian Institute of Technology Indore, Khandwa Road, Indore (India), Fax: (+91) 731-236-4182.
Chempluschem. 2014 Mar;79(3):413-420. doi: 10.1002/cplu.201300348. Epub 2014 Jan 27.
Sonication-induced tryptophan- and tyrosine-based peptide bolaamphiphile nanofibers have been used to synthesize and stabilize Pd nanoparticles under physiological conditions. The peptide bolaamphiphile self-assembly process has been thoroughly studied by using several spectroscopic and microscopic techniques. The stiffness of the soft hydrogel matrix was measured by an oscillatory rheological experiment. FTIR and circular dichroism (CD) experiments revealed a hydrogen-bonded β-sheet conformation of peptide bolaamphiphile molecules in a gel-phase medium. The π-π stacking interactions also played a crucial role in the self-assembly process, which was confirmed by fluorescence spectroscopy. Electron (SEM and TEM) and atomic force microscopy (AFM) studies showed that the peptide bolaamphiphile molecules self-assemble into nanofibrillar structures. Pd nanoparticles were synthesized in the hydrogel matrix in which redox-active tryptophan and tyrosine residues reduce the metal ions to metal nanoparticles. The size of the Pd nanoparticles are in the range of 3-9 nm, and are stabilized by peptide nanofibers. The peptide-nanofiber-supported Pd nanoparticles have shown effective catalytic activity for the removal of N-terminus protecting groups of amino acids and peptides.
超声诱导的基于色氨酸和酪氨酸的肽两亲性纳米纤维已被用于在生理条件下合成和稳定钯纳米颗粒。通过多种光谱和显微镜技术对肽两亲性分子的自组装过程进行了深入研究。通过振荡流变实验测量了软水凝胶基质的刚度。傅里叶变换红外光谱（FTIR）和圆二色性（CD）实验揭示了在凝胶相介质中肽两亲性分子的氢键β-折叠构象。荧光光谱证实了π-π堆积相互作用在自组装过程中也起着关键作用。电子显微镜（扫描电子显微镜和透射电子显微镜）和原子力显微镜研究表明，肽两亲性分子自组装成纳米纤维结构。钯纳米颗粒在水凝胶基质中合成，其中具有氧化还原活性的色氨酸和酪氨酸残基将金属离子还原为金属纳米颗粒。钯纳米颗粒的尺寸在3-9纳米范围内，并由肽纳米纤维稳定。肽纳米纤维负载的钯纳米颗粒已显示出对去除氨基酸和肽的N端保护基团的有效催化活性。
