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Hemoglycin
Hemoglycin (previously termed hemolithin) is a space polymer that is the first polymer of amino acids found in meteorites. Structure Structural work has determined that its 1,494- dalton core unit (glycine18 / hydroxy-glycine4 / Fe2O4) contains iron, but not lithium, leading to the more general term hemoglycin for these molecules. The hemoglycin core contains a total of 22 glycine residues in an anti-parallel beta-sheet chain that is terminated at each end by an iron atom plus two oxygens. Four of these glycine residues are oxidized to hydroxy-glycine with hydroxy groups (−OH) on the alpha carbon. This structure was determined by mass spectrometry of meteoritic solvent extracts and has been confirmed in X-ray scattering by crystals of hemoglycin, and also by optical absorption. Crystals show a 480 nm characteristic absorption that can only exist when hydroxy-glycine residues have R chirality and are C-terminal bonded to iron. History Because hemoglycin has now be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemolithin
Hemolithin (sometimes confused with the similar space polymer hemoglycin) is a proposed protein containing iron and lithium, of extraterrestrial origin, according to an unpublished preprint. The result has not been published in any peer-reviewed scientific journal. The protein was purportedly found inside two CV3 meteorites, Allende and Acfer-086, by a team of scientists led by Harvard University biochemist Julie McGeoch. The report of the discovery was met with some skepticism and suggestions that the researchers had extrapolated too far from incomplete data. Sources The detected hemolithin protein was reported to have been found inside two CV3 meteorites Allende and Acfer 086. Acfer-086, where the complete molecule was detected rather than fragments (Allende), was discovered in Agemour, Algeria in 1990. Structure According to the researchers' mass spectrometry, hemolithin is largely composed of glycine and hydroxyglycine amino acids. The researchers noted that the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Polymer
A polymer () is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rather than crystals. Polymers are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
