title: Effect of chiral helical force field on molecular helical enantiomers and possible origin of biomolecular homochirality.
abstract: Biomolecular homochirality means that the amino acids in proteins, and sugars in nucleic acids, occur in one form: amino acids in L-form and sugars in D-form. So far, the reason why these molecules have such uniform chirality is not known. In this paper, it is suggested that a net natural chiral right-handed helical force field, produced by the Earth's orbital chirality (EOC), could affect the stability of molecular helical enantiomers and make the right-handed helical enantiomers more stable than their left-handed enantiomers, so terrestrial biological systems must select both right-handed helical nucleic acids based on D-sugars, and proteins based on L-amino acids. In given conditions, the maximum energy difference between biomolecular helical enantiomers (deltaEmax=/Eleft-Eright/) caused by the EOC may be calculated theoretically to be in the order: B-DNA > A-RNA > A-DNA >> alpha-protein > beta-protein. Our experimental results strongly supported the hypothesis that the EOC could cause the spontaneous selection and amplification of right-handed helical enantiomers and could be the origin of homochirality on the Earth.
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, USA. yh8933a@american.edu
authors.forename: Y J
authors.initials: YJ
authors.lastname: He
authors.forename: F
authors.initials: F
authors.lastname: Qi
authors.forename: S C
authors.initials: SC
authors.lastname: Qi
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D018534:Earth, Planet; D008968:Molecular Conformation; D009690:Nucleic Acid Conformation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D011506:Proteins; D004247:DNA