Linked Life Data

168535

Source:http://linkedlifedata.com/resource/pubmed/id/168535

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1975-11-1
pubmed:abstractText
Evidence from laboratory and extraterrestrial chemistry is presented consistent with the hypothesis that the original heteropolypeptides on Earth were synthesized spontaneously from hydrogen cyanide and water without the intervening formation of chi-amino acids, a key step being the direct polymerization of atmospheric hydrogen cyanide to polyaminomalononitrile (IV) via dimeric HCN. Molecular orbital calculations (INDO) show that the most probable structure for (HCN)2 is azacyclopropenylidenimine. Successive reactions of hydrogen cyanide with the reactive nitrile side chains of IV then yield heteropolyamidines which are converted by water to heteropolypeptides. To study this postulated modification of a homopolymer to a heteropolymer, poly-chi-cyanoglycine (IX) was prepared from the N-carboxyanhydride of chi-cyanoglycine. Hydrolysis of IX, a polyamide analog of the polyamidine IV, yielded glycine. However, when IX was hydrolysed after being treated with hydrogen cyanide, other chi-amino acids were also obtained including alanine, serine, aspartic acid and glutamic acid, suggesting that the nitrile groups of IX (and therfore of IV) are indeed readily attacked by hydrogen cyanide as predicted. Further theoretical and experimental studies support the view that hydrogen cyanide polymerization along these lines is a universal process that accounts not only for the past formation of primitive proteins on Earth, but also for the yellow-brown-orange colors of Jupiter today and for the presence of water-soluble compounds hydrolyzable to chi-amino acids in materials obtained from environments as diverse as the moon, carbonaceous chondrites and the reaction chambers used to simulate organic synthesis in planetary atmospheres.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0302-1688
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
155-62
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:articleTitle
The origin of proteins: Heteropolypeptides from hydrogen cyanide and water.
pubmed:publicationType
Journal Article