The number of catalytic cycles in an enzyme’s lifetime in cells and why this is important

What is it about?

The continuous replacement of enzymes and other proteins appropriates up to half the maintenance energy budget in microorganisms and plants. High enzyme replacement rates therefore cut the productivity of biosystems ranging from microbial fermentations to crops. However, yardsticks to assess what drives enzyme protein replacement and guidelines on how to reduce it are lacking. Accordingly, we compared enzymes’ lifespans across kingdoms using a new yardstick (‘Catalytic-Cycles-till-Replacement’, CCR) and related CCR to enzyme reaction chemistry. We concluded that (i) many enzymes fail due to collateral damage from the reaction they catalyze, and (ii) such damage and its attendant enzyme replacement costs are mitigable by engineering and are therefore promising targets for synthetic biology.

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Photo by Science in HD on Unsplash

Photo by Science in HD on Unsplash

Why is it important?

The rates at which enzyme proteins are degraded and resynthesized are critical to the cellular energy economy because such turnover can consume about half the maintenance energy budget in microbes and plants. High enzyme protein turnover rates can therefore reduce the productivity of biosystems ranging from microbial fermentations to crops. Slowing the turnover of abundant, fast-turnover enzymes could therefore substantially increase growth rate and biomass yield in plants and other organisms.

Perspectives