News from Nanotechjapan


Enzyme Molecules were Arranged One by One with Nanometer Accuracy

 Kyoto University announced on 1 June 2017, that researchers at the Institute of Advanced Energy of the university has successfully arranged multiple kinds of enzyme molecules one by one exactly onto the targeted place with nanometer accuracy. The results were published online in Journal of the American Chemical Society with Professor Takashi Morii as senior author*.

 The researchers used DNA origami as the scaffold to arrange protein (enzyme) molecules. They designed molecular adaptor that binds the intended protein molecules to a specific DNA sequence on the scaffold. The molecular adaptor is the conjugation of a sequence-specific DNA-binding zinc finger protein and a self-ligating protein tag, and the adaptor expedites the formation of a stable covalent bond between the protein tag and a substrate-modified nucleotide at a specific DNA sequence.

 In this study, by using tailored molecular adaptors for each enzyme, three kinds of enzyme molecules (enzyme1, enzyme2, and enzyme3) were aligned on DNA origami with several ten- nanometer intervals. Enzyme1, enzyme2, and enzyme3 promote the conversion of xylose to xylitol, xylitol to xylulose, xylulose to D-xylulose 5-phosphate, respectively. Observation by AFM revealed that more than 90% of enzyme molecules were arranged correctly at the targeted position. The reaction efficiency of the sequentially aligned enzyme system is 33% higher than that of the simply mixed enzyme system. Because the spacing of the enzyme molecules affected the reaction efficiency, it became clear that the arrangement of the enzyme molecule is important. The researchers named these sequentially aligned enzyme reaction system as "molecular kombinat".

* Thang Minh Nguyen, Eiji Nakata, Masayuki Saimura, Huyen Dinh and Takashi Morii, "Design of Modular Protein-Tags for the Orthogonal Covalent Bond Formation at Specific DNA Sequences", Journal of the American Chemical Society, Just Accepted Manuscript, DOI: 10.1021/jacs.7b01640; Publication Date (Web): May 18, 2017