Multi-Ligand-Binding Flavoprotein Dodecin as a Key Element for Reversible Surface Modification in Nano-biotechnology

作者：Sanchez Cristina Gutierrez; Su Qiang; Schoenherr Holger; Grininger Martin; Noell Gilbert

来源：ACS Nano, 2015, 9(4): 3491-3500.

DOI：10.1021/nn506993s

• dodecin
• flavins and flavoproteins
• multidentate ligands
• multiple or multivalent binding
• QCM-D
• SPR

In this paper the multiple (re)programming of protein DNA nanostructures comprising generation, deletion, and reprogramming on the same flavin-DNA-modified surface is introduced. This work is based on a systematic study of the binding affinity of the multi-ligand-binding flavoprotein dodecin on flavin-terminated DNA monolayers by surface plasnnon resonance and quartz crystal microbalance with dissipation (QCM-D) measurements, surface plasmon fluorescence spectroscopy (SPFS), and dynamic AFM force spectroscopy. Depending on the flavin surface coverage, a single apododecin is captured by one or more surface-immobilized flavins. The corresponding complex binding and unbinding rate constants k(on(QCM)) = 7.7 x 10(3) M-1 . S-1 and k(off(QCM)) = 4.5 x 10(-3) S-1 (K-d(QCM) = 580 nM) were determined by QCM and were found to be in agreement with values for koff determined by RFS and force spectroscopy. Even though a single apododecin flavin bond is relatively weak, stable dodecin monolayers were formed on flavin-DNA-modified surfaces at high flavin surface coverage due to multivalent interactions between apododecin bearing six binding pockets and the surface-bound flavin-DNA ligands. If bi- or multivalent flavin ligands are adsorbed on dodecin monolayers, stable sandwich-type surface-DNA-flavin-apododecin-flavin ligand arrays are obtained. Nevertheless, the apododecin flavin complex is easily and quantitatively disassembled by flavin reduction. Binding and release of apododecin are reversible processes, which can be carried out alternatingly several times to release one type of ligand by an external redox trigger and subsequently replace it with a different ligand. Hence the versatile concept of reprogrammable functional biointerfaces with the multi-ligand-binding flavoprotein dodecin is demonstrated.

• 出版日期2015-4