Question 3: the problem of macromolecular sequences: the forgotten stumbling block

Area of Science:

• Biochemistry
• Astrobiology
• Origin of Life Studies

Background:

• Proteins and nucleic acids are essential biomolecules.
• Understanding the prebiotic synthesis of these molecules is key to origin of life research.
• Current models face challenges in explaining the specific sequences of complex proteins.

Purpose of the Study:

• To evaluate the feasibility of prebiotic synthesis for protein precursors.
• To investigate the constraints on copolymer synthesis relevant to biogenesis.
• To discuss the kinetics and thermodynamics governing the formation of specific biomolecular sequences.

Main Methods:

• Experimental demonstration of co-oligopeptide chain production via prebiotic reactions.
• Theoretical examination of the kinetics and thermodynamics of copolymer synthesis.
• Analysis of constraints imposed by sequence specificity in biogenesis.

Main Results:

• Co-oligopeptide chains of significant length can be experimentally produced under prebiotic conditions.
• A bottom-up approach is insufficient for determining the synthesis conditions of complex, specific proteins.
• The synthesis of copolymers, unlike homopolymers, presents stringent kinetic and thermodynamic challenges.

Conclusions:

• Prebiotic chemistry can generate protein building blocks (co-oligopeptides).
• The specific sequences of proteins like lysozyme are not fully explained by current bottom-up prebiotic synthesis models.
• Kinetics and thermodynamics impose critical constraints on the origin and growth of specific biopolymer sequences.