Protoenzymes: the case of hyperbranched polyesters.

Area of Science:

• Biochemistry
• Polymer Chemistry
• Origin of Life Studies

Background:

• Enzymes, essential biological catalysts, are complex globular structures difficult to synthesize under prebiotic conditions.
• Enzymes utilize cofactors and possess specific microenvironments for catalysis.
• Alternative catalytic structures may have existed before complex enzymes evolved.

Purpose of the Study:

• To investigate hyperbranched polymers as potential prebiotic catalysts.
• To explore the catalytic capabilities of tertiary amine-bearing hyperbranched polyesters.
• To assess the formation of hydrophobic pockets within these polymers for reaction promotion.

Main Methods:

• Synthesis of hyperbranched polyesters using glycerol, triethanolamine, and hydrophobic organic acids (adipic, methylsuccinic acid).
• Probing the ability of these polymers to form hydrophobic pockets.
• Assessing the catalytic efficiency for the Kemp elimination reaction.

Main Results:

• Hyperbranched polyesters were successfully synthesized under plausible prebiotic conditions.
• The polymers demonstrated the ability to form hydrophobic pockets.
• The Kemp elimination reaction rate was increased by up to a factor of 3 compared to the monomeric triethanolamine.

Conclusions:

• Hyperbranched polymers represent a viable alternative to enzymes for prebiotic catalysis.
• The architecture of hyperbranched polymers facilitates the creation of catalytic microenvironments.
• These findings offer insights into the potential chemical origins of life and early catalysis.