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Adsorption of nucleic Acid bases, ribose, and phosphate by some clay minerals.

Hashizume H - Life (Basel) (2015)

Bottom Line: The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations.The behavior of RNA components at clay mineral surfaces needs to be assessed if we are to appreciate how clays might catalyze the formation of nucleosides, nucleotides and polynucleotides in the "RNA world".Here, we review the interactions of some clay minerals with RNA components.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Materials Science, Tsukuba 305-0044, Japan. hashizume.hideo@nims.go.jp.

ABSTRACT
Besides having a large capacity for taking up organic molecules, clay minerals can catalyze a variety of organic reactions. Derived from rock weathering, clay minerals would have been abundant in the early Earth. As such, they might be expected to play a role in chemical evolution. The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations. The behavior of RNA components at clay mineral surfaces needs to be assessed if we are to appreciate how clays might catalyze the formation of nucleosides, nucleotides and polynucleotides in the "RNA world". The adsorption of purines, pyrimidines and nucleosides from aqueous solution to clay minerals is affected by suspension pH. With montmorillonite, adsorption is also influenced by the nature of the exchangeable cations. Here, we review the interactions of some clay minerals with RNA components.

No MeSH data available.


Isotherms for the adsorption of ribose (a) and phosphate (b).
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life-05-00637-f002: Isotherms for the adsorption of ribose (a) and phosphate (b).

Mentions: The isotherm for the adsorption of ribose by Mg2+-montmorillonite is shown in Figure 2a. The points are scattered and very little is adsorbed because ribose is highly basic (pKa = 12.2). Furthermore, ribose would be negatively charged at the experimental pH (≈ 8), and hence be repelled from the (basal) silicate surface. The isotherm for the adsorption of phosphate (Figure 2b) is of the L-type [26], reaching a plateau when the solute concentration exceeds 1.2 mmol·dm−3. At an acidic pH, phosphate can adsorb by electrostatic attraction to the edge surface of montmorillonite particles, which is then positively charged because the isoelectric point of the edge surface of montmorillonite is around pH 6.5 [27]. However, at pH ≈ 8, both the basal and edge surfaces of montmorillonite are negatively charged. Under these conditions, phosphate can still adsorb by ligand exchange with hydroxyl groups attached to “under-coordinated” aluminum ions at particle edges (Figure 1).


Adsorption of nucleic Acid bases, ribose, and phosphate by some clay minerals.

Hashizume H - Life (Basel) (2015)

Isotherms for the adsorption of ribose (a) and phosphate (b).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390872&req=5

life-05-00637-f002: Isotherms for the adsorption of ribose (a) and phosphate (b).
Mentions: The isotherm for the adsorption of ribose by Mg2+-montmorillonite is shown in Figure 2a. The points are scattered and very little is adsorbed because ribose is highly basic (pKa = 12.2). Furthermore, ribose would be negatively charged at the experimental pH (≈ 8), and hence be repelled from the (basal) silicate surface. The isotherm for the adsorption of phosphate (Figure 2b) is of the L-type [26], reaching a plateau when the solute concentration exceeds 1.2 mmol·dm−3. At an acidic pH, phosphate can adsorb by electrostatic attraction to the edge surface of montmorillonite particles, which is then positively charged because the isoelectric point of the edge surface of montmorillonite is around pH 6.5 [27]. However, at pH ≈ 8, both the basal and edge surfaces of montmorillonite are negatively charged. Under these conditions, phosphate can still adsorb by ligand exchange with hydroxyl groups attached to “under-coordinated” aluminum ions at particle edges (Figure 1).

Bottom Line: The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations.The behavior of RNA components at clay mineral surfaces needs to be assessed if we are to appreciate how clays might catalyze the formation of nucleosides, nucleotides and polynucleotides in the "RNA world".Here, we review the interactions of some clay minerals with RNA components.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Materials Science, Tsukuba 305-0044, Japan. hashizume.hideo@nims.go.jp.

ABSTRACT
Besides having a large capacity for taking up organic molecules, clay minerals can catalyze a variety of organic reactions. Derived from rock weathering, clay minerals would have been abundant in the early Earth. As such, they might be expected to play a role in chemical evolution. The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations. The behavior of RNA components at clay mineral surfaces needs to be assessed if we are to appreciate how clays might catalyze the formation of nucleosides, nucleotides and polynucleotides in the "RNA world". The adsorption of purines, pyrimidines and nucleosides from aqueous solution to clay minerals is affected by suspension pH. With montmorillonite, adsorption is also influenced by the nature of the exchangeable cations. Here, we review the interactions of some clay minerals with RNA components.

No MeSH data available.