Self-reporting Biological Nano-systems To Study And Control Bio-molecular Mechanisms On The Single Molecule Level (BIOSCOPE)

Abstract

Abstract in Undetermined Bearing in mind the potential and importance of enzymatic processes it is somewhat surprising that we are not yet able to fully exploit the possibilities that such processes offer. The main reason is that we do not know the mechanism on the molecular scale in terms of the interaction between the enzyme and the substrate or rather the assembly of substrate molecules (see Figure 1.). This is indeed an interfacial process on the molecular scale. Here we recall that the enzymes work at very low concentrations. Thus under relevant conditions the effect of this isolated enzyme molecule in terms of global properties, like interfacial tension, rheology and curvature, on the relatively large substrate interface is very limited or non-existing at all [1, 2]. It is well established that the local effects on the nanoscopic scale are very significant and understanding of their role in governing enzymatic processes is crucial for the progress of nano-science. Unfortunately, these local effects are not possible to be described and determined at the moment, since the relevant and required tools are not available. Current high-resolution methods, such as x-ray crystallography and NMR, have provided a vast array of structural detail for biological molecules [3,4], yet the output of these methods are limited by their static molecular view and ensemble averaging. Recent advances in optical imaging and biomechanical techniques have demonstrated that it is possible to make observations on the dynamic behaviour of single molecules, to determine mechanisms of action at the level of an individual molecule, and to explore heterogeneity among different molecules within a population. These studies have the potential to provide fundamentally new information about biological processes and are critical for a better understanding of molecular movement, dynamics, and function. Single molecule methods provide an alternative set of approaches that will lead to a more direct view of the action of molecules without the need to infer process or function from static structures. The conformational dynamics of biomolecules is crucial to their biological functions. Recent advances in room-temperature single molecule fluorescence spectroscopy allow for real-time observations of conformational motions of individual bio-molecules [5-7], in particular those on the nanometer scale through fluorescence resonance energy transfer (FRET)[7,8]. Single molecule photo-induced electron transfer allows probing the distance between a donor and acceptor (within a protein [9]) on the Angstrom scale. Structural information of individual proteins can also be obtained directly nowadays by using the surface enhanced resonance Raman scattering technique (SERRS) [10,11] (Less)