title: A capillary electrophoresis method to explore the self-assembly of a novel polypeptide ligand with quantum dots.
abstract: Polyhistidine peptides are effective ligands to coat quantum dots (QDs). It is known that both the number of histidine (His) residues repeats and their structural arrangements in a peptide ligand play important roles in the assembly of the peptide onto CdSe/ZnS QDs. However, due to steric hindrance, a peptide sequence with more than six His residue tandem repeats would hardly coordinate well with Zn(2+) in the QD shell to further enhance the binding affinity. To solve this problem, a His-containing peptide ligand, ATTO 590-E2 G (NH)6 (ATTO-NH), was specifically designed and synthesized for assembly with QDs. With sequential injection of QDs and ATTO-NH into the capillary electrophoresis with fluorescence detection, strong Förster resonance energy transfer phenomenon between the QDs and the ATTO 590 dye was observed, indicating efficient self-assembly of the novel peptide onto the QDs to form ATTO-NH capped QDs inside the capillary. The binding stability of the ligand onto the QD was then systematically investigated by titrating with imidazole, His, and a his-tag containing competitive peptide. It is believed that this new in-capillary assay significantly reduced the sample consumption and the analysis time. By functionalizing QDs with certain metal cation-specific group fused peptide ligand, the QD-based probes could be even extended to the online detection of metal cations for monitoring environment in the future.
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.
authors.forename: Jianhao
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.
authors.forename: Chencheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, UK.
authors.forename: Karunakaran A
authors.initials: KA
authors.lastname: Kalesh
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.|State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, Jiangsu, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.
authors.forename: Shumin
authors.initials: S
authors.lastname: Ding
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.
authors.forename: Minli
authors.initials: M
authors.lastname: Fu
authors.affiliation: Department of Chemistry, National University of Singapore, Singapore.
authors.forename: Li-Qian
authors.initials: LQ
authors.lastname: Gao
authors.affiliation: School of Pharmaceutical Engineering and Life Science, Changzhou University, Changzhou, Jiangsu, P. R. China.|Key Laboratory of Synthetic Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, P. R. China.
authors.forename: Pengju
authors.initials: P
authors.lastname: Jiang
mesh_terms: D002412:Cations; D019075:Electrophoresis, Capillary / Q000379:methods*; D031541:Fluorescence Resonance Energy Transfer; D006576:Heterocyclic Compounds, 4 or More Rings; D006639:Histidine; D008024:Ligands; D008670:Metals / Q000032:analysis; D010455:Peptides / Q000737:chemistry*; D045663:Quantum Dots
chemical_list: C521550:Atto590; D002412:Cations; D006576:Heterocyclic Compounds, 4 or More Rings; D008024:Ligands; D008670:Metals; D010455:Peptides; C033223:polyhistidine; D006639:Histidine
keywords: Capillary electrophoresis; Förster resonance energy transfer; Quantum dots; Self-assembly