Boolean Logic Gates Realized with Enzyme-catalyzed Reactions - Unusual Look at Usual Chemical Reactions.

Research in the area of molecular computing systems, in the general framework of unconventional computing, has received high attention and resulted in rapid progress in formulating signal-controlled switchable molecules capable to perform Boolean logic operations and basic arithmetic functions. Extension of this research to biomolecular systems allowed sophisticated computational functions much easier than using synthetic molecular and supramolecular species. The advantage of biomolecular systems comparing with synthetic molecular systems is in their complementarity and compatibility allowing easy assembling multi-component systems from various biomolecules, thus increasing their functional complexity. While DNA-based computing systems are promising faster computing than Si-based electronics, at least for solving some combinatorial problems, due to massive parallel operation, enzyme-based logic systems are less promising for computational applications in their narrow definition. However, they offer novel biosensing and bioactuation features operating in binary Yes/No format. The present review article overviews different kinds of enzyme logic gates exemplified with specific enzymatic reactions/cascades. Motivation for this research and its possible applications are discussed. The review will be helpful to researchers working in this specific area to see the comprehensive collection of logic operations performed by the enzyme reactions. The newcomers to the reviewed area will benefit from the example systems representing various logic functions systematically.