Abstract for the Fourth Foresight Conference on Molecular Nanotechnology.

Methodologies for the construction of superamolecular arrays from biological macromolecules

N. Dotan (a) D. Arad (b) A. Freeman

Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel aviv 69978, ISRAEL

The construction and use of supramolecular arrays in the nanometer scale via self assembly of molecules has recently gained much attention as potential mean for the preparation of miniaturic devices. A new systematic approach and methodologies for the construction of such supramolecular arrays by means of self assembly of selected and modified biological macromolecules will be presented. It consists of the following stages: (a) Identification of potentially usefull "bilding block" exhibiting desired geometry and shape by means of survey of 3D data banks of proteins and nucleic acids; (b) Design of effective means to be added or used in conjunction with the selected macromolecular building blocks and simulation of expected supramolecular arrays structures and stability by means of molecular graphics and modeling; (c) Preparation and synthesis of selected building block and means for their controlled and directed self assembly. From solution into a three dimensional latice; (d) Optimization of environmental conditions (e.g. concentrations, temperature, pH, ionic strength) affecting self - assembly and characterization of structures obtained (e.g. EM ,X - ray); (e) Post modification (e.g. chemical crosslinking and / or addition of functional gruops) of the arrays towards future applications (e.g. conducting arrays; microsensors; catalytic surfaces; ultrafilters);

The feasibility of the suggested approach was demonstrated by formation of a homopolymeric, cross - linked, 3D crystal like array, between lectin (Con - A) tetramer and a specially designed synthetic "bi - ligand". This bi - ligand was desigend and synthesized on the basis of analysis of the complementarity or repulsion created between two Con-A molecules approaching each other by means of modeling and interaction energy calculations, it was expected to induce specific orientation of Con-A molecules connected to it, affecting oriented three dimensional array configuration. The bi - ligand molecules (1,2 ethyl- a -D-mannopyranoside) and Con - A tetramers were readily self assembled into a supramolecular array that can be observed by electron microscopy.