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Improved peptidyl linkers for self-assembly of semiconductor quantum dot bioconjugates

Berti, Lorenzo and D’Agostino, Paola Serena and Boeneman, Kelly and Medintz, Igor L. (2009) Improved peptidyl linkers for self-assembly of semiconductor quantum dot bioconjugates. Nano Research, 2 (2). pp. 121-129. ISSN 1998-0124 (Print) 1998-0000 (Online)

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Official URL: http://www.springerlink.com/content/6122k53v713q2h...

Abstract

We demonstrate improved peptide linkers which allow both conjugation to biomolecules such as DNA and self-assembly with luminescent semiconductor quantum dots. A hexahistidine peptidyl sequence was generated by standard solid phase peptide synthesis and modified with the succinimidyl ester of iodoacetamide to yield a thiol-reactive iodoacetyl polyhistidine linker. The reactive peptide was conjugated to dye-labeled thiolated DNA which was utilized as a model target biomolecule. Agarose gel electrophoresis and fluorescence resonance energy transfer analysis confirmed that the linker allowed the DNA to self-assemble with quantum dots via metal-affinity driven coordination. In contrast to previous peptidyl linkers that were based on disulfide exchange and were thus labile to reduction, the reactive haloacetyl chemistry demonstrated here results in a more stable thioether bond linking the DNA to the peptide which can withstand strongly reducing environments such as the intracellular cytoplasm. As thiol groups occur naturally in proteins, can be engineered into cloned proteins, inserted into nascent peptides or added to DNA during synthesis, the chemistry demonstrated here can provide a simple method for self-assembling a variety of stable quantum dot bioconjugates.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
Faculty of Engineering, Science and Mathematics > School of Chemistry
ID Code:8392
Deposited By:JNCASR
Deposited On:19 Apr 2010 07:16
Last Modified:19 Apr 2010 07:16

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