High pressures increase α-chymotrypsin enzyme activity under perchlorate stress

Area of Science:

• Astrobiology
• Biochemistry
• Geochemistry

Background:

• Deep subsurface environments are characterized by high dissolved ion concentrations and pressures, which can impact life's conditions.
• Perchlorate, an ion found in extreme terrestrial environments and on Mars, poses a significant stressor for life.
• The combined effects of high pressure and perchlorate on biological systems remain largely unexplored.

Purpose of the Study:

• To investigate the interactive effects of high pressure and high perchlorate concentrations on enzymatic activity.
• To determine how these combined stressors influence the stability and function of enzymes.

Main Methods:

• Studied the activity of alpha-chymotrypsin enzyme under varying pressures and perchlorate concentrations.
• Analyzed the conformational phase space of the enzyme in response to pressure and perchlorate.

Main Results:

• High pressures were found to increase alpha-chymotrypsin enzyme activity, even under high perchlorate conditions.
• Perchlorate salts induced a shift in the enzyme's folded phase space towards lower temperatures and pressures.
• The study demonstrates a complex interplay between pressure, perchlorate, and enzyme function.

Conclusions:

• Elevated pressures may enhance habitability in environments with perchlorate stress.
• Deep subsurface environments, potentially including those on Mars, could be more conducive to life than previously assumed.
• This research provides insights into the potential for life in high-pressure, high-ion extraterrestrial settings.