Second, the formation of oligopeptide-like molecules of length up to 20-mers proceeded from L-glutamic acid (Glu) and L-aspartic acid (Asp). Yields of up to 0.17–0.57% were obtained in an acidic solution within 13–183 s at 250–310°C, as evaluated by matrix-assisted laser desorption/ionization mass spectrometry analysis and high-performance liquid chromatography analyses. The oligopeptide-like molecules were assigned as pyroglutamic acid-capped Asp oligopeptides with linear and/or branched linkages. During the elongations, DKP isomers

were not detected. These findings imply that higher oligopeptides could have effectively formed under hydrothermal conditions if some additives, such as mineral catalysts, accelerate the oligopeptide selleck products formation or inhibit the formation of DKP isomers. Holm, N. G. editor (1992), Special issue. Origins Life Evol. Biosphere, 22:1–242. Imai, E., Honda, selleck chemicals llc H., Hatori, K., Brack, A., and Matsuno, K. (1999). Elongation of oligopeptides in a simulated submarine

hydrothermal system. Science, 283:831–833. Kawamura, K. (2000). Monitoring hydrothermal reactions on the millisecond time scale using a micro-tube flow reactor and kinetics of ATP hydrolysis for the RNA world hypothesis. Bull. Chem. Soc. Jpn., 73:1805–1811. Kawamura, K. and Shimahashi, M. (on line first). One-step formation of oligopeptide-like molecules from Glu and Asp in hydrothermal environments. Naturwissenschaften. Kawamura, K., Nishi, T., and Sakiyama, T. (2005). Consecutive elongation of alanine oligopeptides at the second time range under hydrothermal conditions using a micro flow reactor system. J. Am. Chem. Soc., 127:522–523. Miller, S. L. and Lazcano, A. (1995). The origin of life—did it occur at high temperatures? J. Mol. Evol., 41:689–692. E-mail: kawamura@chem.​osakafu-u.​ac.​jp Early History of the Translation Machinery George Fox Dept. Biology and Biochemistry, University of Houston, Houston, Texas The translation machinery has been extensively refined and improved

over the course of evolutionary history. Evidence for its ancient origins exists in that the majority of the most universal Urocanase genes that were likely present in the last common ancestral populations are involved in translation. Ongoing efforts are focused on identifying which ribosomal proteins originated in the ribosome and which were recruited to it in later times. Although many ribosomal proteins are universally distributed, it is unlikely that even these are equally old. Utilizing information from ribosomal assembly maps, functional roles, ribosomal and genomic locations a proposal is made regarding the relative age of these most conserved proteins. In particular, it is argued that the oldest ribosomal proteins are likely L2, L3 and L4. Other ribosomal proteins may have been derived from these. E-mail: fox@uh.​edu Origins of Homochirality Enantiomeric Enrichment on the Prebiotic Earth.