Abstract
Thermally prepared poly-α-amino acids were tested after being stored in the dry state for 5 to 10 years. Polymers effective in catalyzing the hydrolysis of p -nitrophenyl acetate showed the same levels of activity as observed 10 years earlier. Polymers effective in catalyzing the decarboxylation of oxaloacetic acid had in 5 years become insoluble in assay medium; their activity, however, had increased by 32 to 145 percent. The results suggest that particular primitive enzyme molecules could have been stable enough to have contributed to evolutionary processes long after they had been produced.