Fungal Peptaibiotics: Assessing Potential Meteoritic Amino Acid Contamination

• Main Authors: Callahan, M. P., Dworkin, J. P., Glavin, D. P., Elsila, J. E., Bruckner, H.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2010
• Subjects: Lunar and Planetary Science and Exploration; Antarctic; Murchison; Antarc*
• Online Access: http://hdl.handle.net/2060/20100031174

The presence of non-protein alpha-dialkyl-amino acids such as alpha-aminoisobutyric acid (alpha-A1B) and isovaline (Iva), which are relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic amino acids, however, the discovery of alpha-AIB in peptides producers by a widespread group of filamentous fungi indicates the possibility of a terrestrial biotic source for the alpha-AIB observed in some meteorites. The alpha-AIB-containing peptides produced by these fungi are dubbed peptaibiotics. We measured the molecular distribution and stable carbon and nitrogen isotopic ratios for amino acids found in the total hydrolysates of four biologically synthesized peptaibiotics. We compared these aneasurenetts with those from the CM2 carbonaceous chondrite Murchison and from three Antarctic CR2 carbonaceous chondrites in order to understand the peptaibiotics as a potential source of meteoritic contamination.