Meteoritic Proteins with Glycine, Iron and Lithium

• Published in: arXiv.org 2021-02
• Main Authors: McGeoch, Malcolm W, Dikler, Sergei, McGeoch, Julie E M
• Format: Article
• Language: English
• Subjects: Glycine; Ions; Iron; Lithium; Mass spectrometry; Meteorites; Meteors & meteorites; Molecular structure; Polymers; Proteins; Room temperature; Scientific imaging; Silicon; Spectroscopy
• ISSN: 2331-8422

We report that polymer amide [1] with a protein backbone of mainly glycine units and iron is present in the CV3 meteorites Acfer 086, Allende and KABA. The evidence for this is from particles of these meteorites after Folch extraction being analyzed by MALDI mass spectrometry and from the 3D physical structures that form in the various Folch solvent phases. The two physical forms we observe are branching rods and entrapping spheres on the 100micron scale. Two potential molecular structures of polymer amide are presented in this report. One we term hemolithin of mass 2320Da, contains glycine, hydroxy-glycine, Fe, O and Li. The other, we term hemoglycin of mass 1494Da is of glycine, hydroxy-glycine, Fe and O. Hemoglycin is connected covalently in triplets by silicon to form a triskelion. Analysis of the complete spectrum of isotopes associated with each molecular fragment shows very high 2H enhancement above terrestrial averaging 25,700 parts per thousand (sigma = 3,500, n=15), confirming extra-terrestrial origin and hence the existence of these molecules within the asteroid parent body of the CV3 meteorite class. The hemoglycin triskelia join via silicon bonds into an extended lattice, as seen in mass spectrometry of lattice fragments at m/z 4641 and above [2]. The identification of hemolithin and hemoglycin required careful methodology at room temperature with the minimum of steps up to mass spectrometry analysis ensuring that only the laser step fragmented the molecules. The 3D structures were imaged through permanently closed Folch extraction V-vials at a magnification of 10.