The Many-Chemicals Problem of Systems Chemistry

Abstract

An E. coli cell contains ~2500 different chemicals which combine into an ordered biochemical reaction network out of which emerges a living system. A chemist taking 2500 different chemicals from a laboratory chemical cabinet and combining them together will likely cause an explosive disaster and produce an intractable chemical sludge. Systems Chemistry aspires to construct systems whose complexity rivals that of life. However, to do this we will need to learn how to combine hundreds or thousands of different chemicals together to form a functional system without descending into a disordered chemical sludge. This is the Many-Chemicals Problem of Systems Chemistry. I explore a key strategy life employs to overcome this challenge. Namely, the combination of kinetically stable and thermodynamically activated molecules (e. g. ATP) with enzyme catalysts (e. g. histidine kinases). I suggest how the strategy could have begun at the origin of life. Finally, I assess the implications of this strategy for Systems Chemistry and how it will enable systems chemists to construct systems whose complexity rivals that of life.