Self-Propagating β-Sheet Polypeptide Structures as Prebiotic Informational Molecular Entities: The Amyloid World

• Published in: Origins of life and evolution of biospheres Vol. 39; no. 2; pp. 141 - 150
• Main Author: Maury, C. P. J
• Format: Journal Article
• Language: English; Dutch
• Published: Dordrecht Dordrecht : Springer Netherlands 01.04.2009; Springer Netherlands; Springer Nature B.V
• Subjects: Aggregates; Amyloid - chemistry; Astronomy; Astrophysics and Astroparticles; Biochemistry; Biomedical and Life Sciences; Earth Sciences; Epigenetics; Evolution, Molecular; Information processing; Information systems; Life Sciences; Models, Molecular; Observations and Techniques; Peptides - chemistry; Prebiotic Chemistry; Prions - chemistry; Protein Conformation; Protein structure; Protein turnover; Ribonucleic acid; RNA; Transcription; Molecular evolution; Origin of life; Prebiotic chemistry; Prions; Memory; Replication; Amyloid; Protein-world; sheet conformation
• ISSN: 0169-6149; 1573-0875
• DOI: 10.1007/s11084-009-9165-6

The idea is advanced that under the extreme earth conditions for ~3.9 billions years ago, protein-based β-sheet molecular structures were the first self-propagating and information-processing biomolecules that evolved. The amyloid structure of these aggregates provided an effective protection against the harsh conditions known to decompose both polyribonucleotides and natively folded polypeptides. In the prebiotic amyloid world, both the replicative and informational functions were carried out by structurally stable β-sheet protein aggregates in a prion-like mode involving templated self-propagation and storage of information in the β-sheet conformation. In this amyloid (protein)-first, hybrid replication-metabolism view, the synthesis of RNA, and the evolvement of an RNA-protein world, were later, but necessary events for further biomolecular evolution to occur. I further argue that in our contemporary DNA[leftright arrow]RNA[rightward arrow]protein world, the primordial β-conformation-based information system is preserved in the form of a cytoplasmic epigenetic memory.