title: Minor Groove 3-Deaza-Adenosine Analogues: Synthesis and Bypass in Translesion DNA Synthesis.
abstract: Anticancer drugs that alkylate DNA in the minor groove may give rise to 3-alkyl-adenosine adducts that interfere with replication, inducing apoptosis in rapidly dividing cancer cells. However, translesion DNA synthesis (TLS) by polymerase enzymes (Pols) with the capacity to bypass DNA adducts may contribute to damage tolerance and drug resistance. 3-Alkyl-adenosine adducts are unstable and depurinate, which is a barrier to addressing chemical and enzymatic aspects of how they impact the progress of DNA Pols. To characterize structure-based relationships of 3-adenine alkylation relevant to cancer drugs on duplex stability and DNA Pol-catalyzed DNA synthesis, we synthesized stable 3-deaza-3-alkyl-adenosine analogues, including 3-deaza-3-phenethyl-adenosine and 3-deaza-3-methoxynaphthylethyl-adenosine, and incorporated them into oligonucleotides. A moderate reduction of duplex stability was observed on the basis of thermal denaturation data. Replication studies using purified Y-family human DNA Pols hPol η, κ, and ι indicated that these enzymes can perform TLS over the modified bases. hPol η had higher misincorporation rates when synthesizing opposite the modified bases compared with adenine, whereas hPol κ and ι maintained high fidelity. These results provide insight into how alterations in chemical structure reduce bypass of minor-groove adducts, and provide novel chemical probes for evaluating minor-groove DNA alkylation.
authors.affiliation: Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland.
authors.forename: Stefano
authors.identifier: http://orcid.org/0000-0001-8510-5861
authors.initials: S
authors.lastname: Malvezzi
authors.affiliation: Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland.
authors.forename: Todor
authors.initials: T
authors.lastname: Angelov
authors.affiliation: Department of Health Sciences and Technology, ETH Zurich, Schmelzbergstrasse 9, 8092, Zurich, Switzerland.
authors.forename: Shana J
authors.initials: SJ
authors.lastname: Sturla
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism; D020029:Base Pairing; D001665:Binding Sites; D020134:Catalytic Domain; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D018736:DNA Adducts / Q000737:chemistry; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D044366:Transition Temperature; D000094769:DNA Polymerase iota; D000099270:Y-Family DNA Polymerases
chemical_list: D000241:Adenosine; D004247:DNA; D018736:DNA Adducts; D004259:DNA-Directed DNA Polymerase; D009841:Oligonucleotides; D000094769:DNA Polymerase iota; C404302:POLK protein, human; D000099270:Y-Family DNA Polymerases; C000722070:POLI protein, human
keywords: DNA damage; DNA replication; antiproliferation; nucleosides; oligonucleotides