Scientific Reports (Aug 2021)

Perchlorate salts confer psychrophilic characteristics in α-chymotrypsin

  • Stewart Gault,
  • Michel W. Jaworek,
  • Roland Winter,
  • Charles S. Cockell

DOI
https://doi.org/10.1038/s41598-021-95997-2
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 9

Abstract

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Abstract Studies of salt effects on enzyme activity have typically been conducted at standard temperatures and pressures, thus missing effects which only become apparent under non-standard conditions. Here we show that perchlorate salts, which are found pervasively on Mars, increase the activity of α-chymotrypsin at low temperatures. The low temperature activation is facilitated by a reduced enthalpy of activation owing to the destabilising effects of perchlorate salts. By destabilising α-chymotrypsin, the perchlorate salts also cause an increasingly negative entropy of activation, which drives the reduction of enzyme activity at higher temperatures. We have also shown that α-chymotrypsin activity appears to exhibit an altered pressure response at low temperatures while also maintaining stability at high pressures and sub-zero temperatures. As the effects of perchlorate salts on the thermodynamics of α-chymotrypsin’s activity closely resemble those of psychrophilic adaptations, it suggests that the presence of chaotropic molecules may be beneficial to life operating in low temperature environments.