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Adenosine monophosphate forms ordered arrays in multilamellar lipid matrices: insights into assembly of nucleic acid for primitive life.

Toppozini L, Dies H, Deamer DW, Rheinstädter MC - PLoS ONE (2013)

Bottom Line: Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed.Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity.This structure may facilitate polymerization of the nucleotides into RNA-like polymers.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada. toppozl@mcmaster.ca

ABSTRACT
A fundamental question of biology is how nucleic acids first assembled and then were incorporated into the earliest forms of cellular life 4 billion years ago. The polymerization of nucleotides is a condensation reaction in which phosphodiester bonds are formed. This reaction cannot occur in aqueous solutions, but guided polymerization in an anhydrous lipid environment could promote a non-enzymatic condensation reaction in which oligomers of single stranded nucleic acids are synthesized. We used X-ray scattering to investigate 5'-adenosine monophosphate (AMP) molecules captured in a multilamellar phospholipid matrix composed of dimyristoylphosphatidylcholine. Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed. Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity. This structure may facilitate polymerization of the nucleotides into RNA-like polymers.

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Two-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC; B AMP:DMPC 1∶2; C AMP:DMPC 1∶1; D AMP:DMPC 2∶1; E AMP:DMPC 3∶1. All ratios are molar ratios. qz and q// are the out-of-plane and in-plane components of the scattering vector, Q.
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pone-0062810-g002: Two-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC; B AMP:DMPC 1∶2; C AMP:DMPC 1∶1; D AMP:DMPC 2∶1; E AMP:DMPC 3∶1. All ratios are molar ratios. qz and q// are the out-of-plane and in-plane components of the scattering vector, Q.

Mentions: Five different membrane complexes with different concentrations of AMP molecules were studied, as detailed in the Materials and Methods Section. Figure 2 shows 2-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC (D), B AMP:DMPC 1∶2, C AMP:DMPC 1∶1, D AMP:DMPC 2∶1 and E AMP:DMPC 3∶1. The ratios are given as molar ratios. As depicted in Figure 1, the samples were oriented such that the q// axis probed lateral membrane structure and the perpendicular axis, qz, probed out-of-plane structure of the multilamellar membrane complexes. The data in Figure 2 cover a large area of reciprocal space and allow the molecular structure of the membrane/AMP complexes to be deduced.


Adenosine monophosphate forms ordered arrays in multilamellar lipid matrices: insights into assembly of nucleic acid for primitive life.

Toppozini L, Dies H, Deamer DW, Rheinstädter MC - PLoS ONE (2013)

Two-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC; B AMP:DMPC 1∶2; C AMP:DMPC 1∶1; D AMP:DMPC 2∶1; E AMP:DMPC 3∶1. All ratios are molar ratios. qz and q// are the out-of-plane and in-plane components of the scattering vector, Q.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3646914&req=5

pone-0062810-g002: Two-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC; B AMP:DMPC 1∶2; C AMP:DMPC 1∶1; D AMP:DMPC 2∶1; E AMP:DMPC 3∶1. All ratios are molar ratios. qz and q// are the out-of-plane and in-plane components of the scattering vector, Q.
Mentions: Five different membrane complexes with different concentrations of AMP molecules were studied, as detailed in the Materials and Methods Section. Figure 2 shows 2-dimensional X-ray intensity maps for all measured concentrations: A pure DMPC (D), B AMP:DMPC 1∶2, C AMP:DMPC 1∶1, D AMP:DMPC 2∶1 and E AMP:DMPC 3∶1. The ratios are given as molar ratios. As depicted in Figure 1, the samples were oriented such that the q// axis probed lateral membrane structure and the perpendicular axis, qz, probed out-of-plane structure of the multilamellar membrane complexes. The data in Figure 2 cover a large area of reciprocal space and allow the molecular structure of the membrane/AMP complexes to be deduced.

Bottom Line: Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed.Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity.This structure may facilitate polymerization of the nucleotides into RNA-like polymers.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada. toppozl@mcmaster.ca

ABSTRACT
A fundamental question of biology is how nucleic acids first assembled and then were incorporated into the earliest forms of cellular life 4 billion years ago. The polymerization of nucleotides is a condensation reaction in which phosphodiester bonds are formed. This reaction cannot occur in aqueous solutions, but guided polymerization in an anhydrous lipid environment could promote a non-enzymatic condensation reaction in which oligomers of single stranded nucleic acids are synthesized. We used X-ray scattering to investigate 5'-adenosine monophosphate (AMP) molecules captured in a multilamellar phospholipid matrix composed of dimyristoylphosphatidylcholine. Bragg peaks corresponding to the lateral organization of the confined AMP molecules were observed. Instead of forming a random array, the AMP molecules are highly entangled, with the phosphate and ribose groups in close proximity. This structure may facilitate polymerization of the nucleotides into RNA-like polymers.

Show MeSH
Related in: MedlinePlus