Construction of Protocellular Structures under Simulated Primitive Earth Conditions

Abstract

We have developed experimental approaches for construction of protocellular structures under simulated primitive earth conditions and have studied their formation and characteristics. Three kinds of protein envelopes were constructed in situ from amino acids under simulated primitive earth conditions such as a fresh water tide pool, a warm sea, and a submarine hydrothermal vent. One protein envelope was formed from a mixture of amino acid amides at 80°C using multiple hydration-dehydration cycles. Marigranules, protein envelope structures, were formed from the mixtures of glycine and acidic, basic and aromatic amino acids at 105°C in a modified sea medium enriched With essential transition elements. Thermostable microspheres were also formed from a mixture of glycine, alanine, valine, and aspartic acid at 250°C and above. The microspheres were not formed at lower temperatures and consisted of silicates and peptide-like plymers containing imide bonds and amino acid residues enriched in valine. Amphiphilic proteins with molecular weight of 2000 were necessary for the formation of the protein envelopes. © 1987, The Chemical Society of Japan. All rights reserved.