Hemolithin

Hemolithin (now known as hemoglycin) is a proposed protein containing iron and lithium, of extraterrestrial origin, according to an unpublished preprint.^[1][6][7][8] The result has not been published in any peer-reviewedscientific journal. The protein was purportedly found inside two CV3meteorites, Allende and Acfer-086,^[1][2][4] by a team of scientists led by Harvard University biochemist Julie McGeoch.^[1][2] The report of the discovery was met with some skepticism and suggestions that the researchers had extrapolated too far from incomplete data.^[9][10]

The detected hemolithin protein was reported to have been found inside two CV3 meteorites Allende and Acfer 086.^[4] Acfer-086, where the complete molecule was detected rather than fragments (Allende), was discovered in Agemour, Algeria, in 1990.^[2][5]

According to the researchers' mass spectrometry, hemolithin is largely composed of glycine and hydroxyglycineamino acids.^[10] The researchers noted that the protein was related to "very high extraterrestrial" ratios of Deuterium/Hydrogen (D/H);^[2] such high D/H ratios are not found anywhere on Earth, but are "consistent with long-period comets"^[3] and suggest, as reported, "that the protein was formed in the proto-solar disc or perhaps even earlier, in interstellar molecular clouds that existed long before the Sun's birth".^[2]

ربما بدأ التطور الطبيعي للهيموليثين بتكوّن جزيئات الجليسين أولًا، ثم ارتباطها لاحقًا بجزيئات جليسين أخرى لتكوين سلاسل بوليمرية ، ثم اتحادها مع ذرات الحديد والأكسجين. تقع ذرات الحديد والأكسجين في نهاية الجزيء المكتشف حديثًا. ويتكهن الباحثون بأن مجموعة أكسيد الحديد المتكونة في نهاية الجزيء قد تكون قادرة على امتصاص الفوتونات ، مما يمكّن الجزيء من تحليل الماء (H₂O ₎ إلى هيدروجين وأكسجين ، وبالتالي إنتاج مصدر طاقة قد يكون مفيدًا لتطور الحياة . ^{[ ٢ ]}

أعرب عالم الأحياء الفلكية والكيميائي جيفري بادا عن مخاوفه بشأن الاكتشاف المحتمل للبروتين، معلقًا: "تكمن المشكلة الرئيسية في وجود هيدروكسي جليسين ، الذي لم يُرصد من قبل، على حد علمي، في النيازك أو في التجارب ما قبل الحيوية . كما أنه غير موجود في أي بروتينات... لذا، يُعدّ هذا الحمض الأميني غريبًا في نيزك، وأنا أشكّ بشدة في النتائج." ^{[ 10 ]} وبالمثل، صرّح لي كرونين من جامعة غلاسكو : "البنية غير منطقية." ^{[ 9 ]}

الهيموليثين هو اسم جزيء بروتيني معزول من نيزكين من نوع CV3 ، وهما أليندي وأكفر-086. تبلغ نسبة الديوتيريوم إلى الهيدروجين فيه 26 ضعف النسبة الأرضية، وهو ما يتوافق مع تكوّنه في سحابة جزيئية بين النجوم ، أو لاحقًا في القرص الكوكبي الأولي في بداية النظام الشمسي قبل 4.567 مليار سنة. أما العناصر التي يتكون منها، وهي الهيدروجين والليثيوم والكربون والأكسجين والنيتروجين والحديد، فقد كانت جميعها متاحة لأول مرة قبل 13 مليار سنة، بعد انتهاء الجيل الأول من النجوم الضخمة بأحداث التخليق النووي .

The research leading to the discovery of Hemolithin started in 2007 when another protein, ATP synthase subunit C, one of the first to form on Earth, was observed to entrap water.^[11] That property being useful to chemistry before biochemistry on earth developed, theoretical enthalpy calculations on the condensation of amino acids were performed in gas phase space asking: "whether amino acids could polymerize to protein in space?" - they could, and their water of condensation aided their polymerization.^[12] This led to several manuscripts of isotope and mass information on Hemolithin.^{[1][13][14][15]}

A comment from the Harvard research leader on Hemolithin/Hemoglycin JEMMc – Hemolithin is now termed hemoglycin. Hemoglycin, a space polymer of glycine and iron has been extensively characterized ^{[16][17][18][19][20][21][22][23][24][25][26]} and it does contain lithium in some samples.^[20] The research and now needs to be considered in the context of 4 areas of astronomy and planetary science: 1st in astronomy, the period between Pop III and Pop II stars, when the constituent elements of hemoglycin first formed even as early as 500 My into cosmic time.^[16] 2nd in molecular clouds and protoplanetary disks where the polymer is likely to form and function in accretion.^[21][24][25] Thus, the polymer could be a major player in solar system formation throughout the Universe. 3rd after in-fall to planets like Earth, where on Earth it could have kick-started the Great Oxygenation Event (GOE).^[24] 4th on exo-planets that evolve biochemistry like Earth, it could be asked whether the formation of DNA involves hemoglycin as a template. Guanine and cytosine nucleotide bases could form and bind to the 5 nm glycine rods of in-fall hemoglycin to start the coding of glycine.^[27]

Hemoglycin is not a biological molecule, being outside of biochemistry, that is, abiotic. It may have first formed 500 million years into cosmic time as a structure that could absorb photons from 0.2-15 μm,^{[22][23][24][25]} be available throughout the Universe, and provide energy to drive adjacent space chemistry. On its in-fall to exo-planets like Earth it could absorb solar ultraviolet and donate energy to early chemical systems. Hemoglycin could therefore be thought of as an abiotic absorber of light, a supplier of energy and an accretor of matter. Synthetic hemoglycin synthesis will be attempted in 2025 to aid acquisition of a refined x-ray diffraction set for its structure. Hemoglycin crystals from meteorites, and stromatolites, to date are fiber-like or multiple.^[21][23][24] A comparison of the MALDI mass spectrometry fragmentation patterns^[20][26] of synthetic and extracted hemoglycin will be informative.

• Earliest known life forms
• Evolutionary history of life
• Extraterrestrial: The First Sign of Intelligent Life Beyond Earth
• List of interstellar and circumstellar molecules
• Panspermia