Etheno-Substituted Nucleotides and Coenzymes: Fluorescence and Biological Activity

Leonard, Nelson J.; Barrio, Jorge R.

doi:10.3109/10409238409102299

Cited by 158 publications

(124 citation statements)

References 260 publications

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“…Early work is traced to Shapiro and Leonard, who independently examined the reactions of nucleosides with glyoxal, malondialdehyde, chloroacetaldehyde, and related biselectrophiles. 8,9 Galliana and Pantarotto characterized the 8-hydroxypyrimido[1,2-α]purin-10 (3H)-one (γ-OH-PdG, 9) adduct from the reaction of acrolein with dG. 10 Chung and Hecht concurrently reported the crotonaldehyde adduct of dG (11)(12), 11 and explored the reactivity of enals and enones with dG.…”

Section: Introductionmentioning

confidence: 99%

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Interstrand DNA Cross-Links Induced by α,β-Unsaturated Aldehydes Derived from Lipid Peroxidation and Environmental Sources

et al. 2008

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ConspectusSignificant levels of the 1,N 2 -γ-hydroxypropano-dG adducts of the α,β-unsaturated aldehydes acrolein, crotonaldehyde, and 4-hydroxy-2E-nonenal (HNE) have been identified in human DNA, arising from both exogenous and endogenous exposure. They yield interstrand DNA cross-links between guanines in the neighboring C•G and G•C base pairs located in 5′-CpG-3′ sequences, as a result of opening of the 1,N 2 -γ-hydroxypropano-dG adducts to form reactive aldehydes that are positioned within the minor groove of duplex DNA. Using a combination of chemical, spectroscopic, and computational methods, we have elucidated the chemistry of cross-link formation in duplex DNA. NMR spectroscopy revealed that, at equilibrium, the acrolein and crotonaldehyde cross-links consist primarily of interstrand carbinolamine linkages between the exocyclic amines of the two guanines located in the neighboring C•G and G•C base pairs located in 5′-CpG-3′ sequences, that maintain the Watson-Crick hydrogen bonding of the cross-linked base pairs. The ability of crotonaldehyde and HNE to form interstrand cross-links depends upon their common relative stereochemistry at the C6 position of the 1,N 2 -γ-hydroxypropano-dG adduct. The stereochemistry at this center modulates the orientation of the reactive aldehyde within the minor groove of the doublestranded DNA, either facilitating or hindering the cross-linking reactions; it also affects the stabilities of the resulting diastereoisomeric cross-links. The presence of these cross-links in vivo is anticipated to interfere with DNA replication and transcription, thereby contributing to the etiology of human disease. Reduced derivatives of these cross-links are useful tools for studying their biological processing. IntroductionThe α,β-unsaturated aldehydes (enals) acrolein, crotonaldehyde, and 4-hydroxynonenal (4-HNE) (Scheme 1) are endogenous byproducts of lipid peroxidation, arising as a consequence of oxidative stress. [1][2][3][4] Acrolein and crotonaldehyde exposures also occur from exogenous sources, e.g., cigarette smoke 5 and automobile exhaust. 6 Enals react with DNA nucleobases to give exocyclic adducts; they also react with proteins. 7 Addition of enals to dG involves Michael addition of the N 2 -amine to give N 2 -(3-oxopropyl)-dG adducts (1, 3-8), followed by * Michael P. Stone telephone, 615-322-2589; fax, 615-322-7591; michael.p The lipid peroxidation product 4-HNE afforded related dGadducts (13-16). 14 Identification of acrolein adducts of other nucleosides followed. 15,16 The principal acrolein adduct is γ-OH-PdG (9), 10,12 although the regioisomeric 6-hydroxypyrimido[1,2-a]purin-10(3H)-one (α-OH-PdG, 10) has also been observed. 12,17 The γ-OH-PdG adduct (9) exists as a mixture of C8-OH epimers. With crotonaldehyde, addition at N 2 -dG creates a stereocenter at C6. Of four possible products, the two with the trans relative configurations at C6 and C8 (11,12) are observed. 12,18 These are also formed through the reaction of dG with two equivalents of acetaldehyde. 5,19,20 The cor...

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Section: Introductionmentioning

confidence: 99%

“…15,16 The principal acrolein adduct is γ-OH-PdG (9), 10,12 although the regioisomeric 6-hydroxypyrimido[1,2-a]purin-10(3H)-one (α-OH-PdG, 10) has also been observed. 12,17 The γ-OH-PdG adduct (9) exists as a mixture of C8-OH epimers. With crotonaldehyde, addition at N 2 -dG creates a stereocenter at C6.…”

Section: Introductionmentioning

confidence: 99%

Interstrand DNA Cross-Links Induced by α,β-Unsaturated Aldehydes Derived from Lipid Peroxidation and Environmental Sources

et al. 2008

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“…Studies of the nucleotide cleft in actin were facilitated by the development of the fluorescent etheno-labeled nucleotide analogs, €-ATP and €-ADP (Secrist et al, 1972;Leonard, 1984). Early work utilizing etheno-nucleotides led to a controversy over whether G-and F-actin showed different fluorescent lifetimes for bound €-ATP (Mihashi & Wahl, 1975;Harvey et al, 1977).…”

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confidence: 99%

The accessibility of etheno‐nucleotides to collisional quenchers and the nucleotide cleft in G‐ and F‐actin

Root

Reisler

1992

Protein Science

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Recent publication of the atomic structure of G-actin (Kabsch, W., Mannherz, H.G., Suck, D., Pai, E.F., & Holmes, K.C., 1990, Nature 347, 37-44) raises questions about how the conformation of actin changes upon its polymerization. In this work, the effects of various quenchers of etheno-nucleotides bound to G-and F-actin were examined in order to assess polymerization-related changes in the nucleotide phosphate site. The Mg2+-induced polymerization of actin quenched the fluorescence of the etheno-nucleotides by approximately 20% simultaneously with the increase in light scattering by actin. A conformational change at the nucleotide binding site was also indicated by greater accessibility of F-actin than G-actin to positively, negatively, and neutrally charged collisional quenchers. The difference in accessibility between G-and F-actin was greatest for I-, indicating that the environment of the etheno group is more positively charged in the polymerized form of actin. Based on calculations of the change in electric potential of the environment of the etheno group, specific polymerization-related movements of charged residues in the atomic structure of G-actin are suggested. The binding of S-1 to €-ATP-G-actin increased the accessibility of the etheno group to I-even over that in Mg2+-polymerized actin. The quenching of the etheno group by nitromethane was, however, unaffected by the binding of S-1 to actin. Thus, the binding of S-1 induces conformational changes in the cleft region of actin that are different from those caused by Mg2+ polymerization of actin. The pH dependence of collisional quenching shows that the cleft region is more accessible to collisional quenchers at pH 7 than at higher pH and suggests that changes in the environment of the cleft might contribute to the faster polymerization rates observed at lower pH.Keywords: actin; collisional quenching; nucleotide site; polymerization; structure The recently published atomic structure of G-actin facilitates the search for specific conformational changes in the actin molecule at the atomic level. Because the X-ray crystallographic structure was solved for G-actin and not F-actin, a question of particular significance is how the conformation of G-actin changes upon its polymerization to F-actin. It is known that actin hydrolyzes ATP to ADP during polymerization

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“…Preliminary assays with calf thymus DNA (results not shown) have demonstrated that, as in many other cases [19,201, this chemical modification can be performed on single-stranded but not on double-stranded nucleic acids. Under the experimental conditions of the reaction of methyl chlorotetrolate with poly(A) the latter is in a single-stranded form [14]; no reaction was observed at pH values lower than 7.…”

Section: Discussionmentioning

confidence: 99%

Reactions of nucleic acid bases with α‐acetylenic esters

Roques

Olomucki

1987

European Journal of Biochemistry

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The reaction of chlorotetrolic (4-chloro-2-butynoic) esters with adenine and cytosine derivatives, in which a new heterocycle bearing an alkylating chloromethyl side chain is fused to the purine or pyrimidine ring, was extended to poly(A) and poly(C) used as models of nucleic acids. The derivatization proceeds under mild conditions and its extent can be controlled by the reaction time. The additional rings can exist in two isomeric forms and the nature of the isomer formed depends on steric factors in the vicinity of the reacting base. The reaction with chlorotetrolic esters discriminates between the single-stranded (reactive) and double-stranded (unreactive) forms, between the exposed an hidden adenine and cytosine bases and even between the exposed and sterically hindered fragments of the base moiety and thus allows structural investigations of these nucleic acids. The chloromethyl group of the derivatized nucleobases can be used to bind the modified polymers to other molecules.In preceding papers [l -31 we have shown that the nucleic acid bases in adenine and cytosine (but not guanine) nucleotides and/or nucleosides react easily with a-acetylenic esters. Thus, for example, treatment of adenosine with a chlorotetrolic (4-chloro-2-butynoic) acid ester in hydroalcoholic solution of apparent pH 4-5, at room temperature, leads to the %ox0 derivative in good yield, while at pH 7 the isomeric 7-0x0 compound is obtained (see Scheme). In the case of cytidine, whatever the pH of the reaction medium, only product 3 was isolated. Thus, the triple bond and the ester group of chlorotetrolic esters react with the nucleobases while the chloromethyl group remains as a substituent on the new heterocycle fused to the original purine or pyrimidine ring.This new derivatization of nucleobases was first studied on nucleosides and nucleotides and some basic information about this reaction was gained at this model level. An interesting feature of this derivatization is the mildness of the experimental conditions under which it occurs. It could therefore be anticipated that this reaction might be used not only for the synthesis of analogues of small molecules containing a nucleobase fragment but also for chemical modification of nucleic acids. The use of chlorotetrolic esters for a controlled derivatization of a certain number of residues in nucleic acids could offer some attractive prospects, among others the possibility of investigating the structure of these macromolecules or of cross-linking nucleic acids to proteins or to some other molecules. This paper describes the first attempt to extend the reaction to nucleic acids using poly(A) and poly(C) as models.

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Etheno-Substituted Nucleotides and Coenzymes: Fluorescence and Biological Activity

Cited by 158 publications

References 260 publications

Interstrand DNA Cross-Links Induced by α,β-Unsaturated Aldehydes Derived from Lipid Peroxidation and Environmental Sources

Interstrand DNA Cross-Links Induced by α,β-Unsaturated Aldehydes Derived from Lipid Peroxidation and Environmental Sources

The accessibility of etheno‐nucleotides to collisional quenchers and the nucleotide cleft in G‐ and F‐actin

Reactions of nucleic acid bases with α‐acetylenic esters

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