カワムラ　クニオ   KAWAMURA Kunio   川村　邦男    所属   広島修道大学  人間環境学部    職種   教授
発表年月日	2011/07
発表テーマ	The role of naturally occurring minerals for the formation of oligopeptides unde hydrothermal conditions by using Mineral-mediate hydrothermal reactor system
会議名	ISSOL, IAU ISSOL – The International Astrobiology Society and Bioastronomy (IAU C51) Joint International Conference
学会区分	国際学会
発表形式	ポスター
開催地名	Montpellier, France
発表者・共同発表者	Kunio Kawamura, Hitoshi Takeya, Takao Kushibe, Yuka, Koizumi
概要	Phylogenetic analyses suggest that life originated in hydrothermal environments, though the nature of the last common ancestor (LCA) remains debated. Simulation studies under hydrothermal vent conditions support this, but the oligopeptides formed are generally too short and low in yield for biochemical function. This is due to rapid diketopiperazine (DKP) formation, the absence of condensation agents, and limited time to study mineral effects. Using a hydrothermal flow reactor system (HFRS), we previously achieved efficient elongation from (Ala)₄ to (Ala)₅ (~10 %) and one-step formation of 20-mer oligopeptides from Glu and Asp. Condensation agents were also tested but not yet successful. Here, we developed a mineral-mediated HFRS (Mineral-HFRS) capable of monitoring reactions in 1–200 s at 300 °C and 30 MPa with mineral particles (0.02–2 mm). Using this system, we found that carbonate minerals (calcite and dolomite) enhanced (Ala)₄ elongation to (Ala)₅ (~28 %), while sulfide minerals had little effect.