Document Detail

Generation of guanine-amino acid cross-links by a free radical combination mechanism.
MedLine Citation:
PMID:  24810398     Owner:  NLM     Status:  Publisher    
A direct method has been developed for the in vitro synthesis of stable DNA-protein cross-links (DPC's) between guanine and amino acids (lysine and arginine). This method employs the combination of guanine neutral radicals, G(-H)˙, and side-chain C-centered amino acid radicals. The latter were generated indirectly after first causing the selective photoionization of 2-aminopurine (2AP) embedded in the oligonucleotide, 5'-d(CC[2AP]TCGCTACC), by intense nanosecond 308 nm excimer laser pulses. The 2AP radical cation deprotonates rapidly to form the 2AP(-H)˙ neutral radical which, in turn, oxidizes the nearby guanine to form the neutral guanine G(-H)˙ radical, as described previously (Shafirovich et al., J. Phys. Chem. B, 2001, 105, 8431). In parallel, the hydrated electrons, generated by the photoionization of 2AP, are scavenged by nitrous oxide to generate hydroxyl radicals. In the presence of a large excess of the amino acids, the hydroxyl radicals oxidize the latter to produce C-centered amino acid radicals that combine with the G(-H)˙ radicals to form the guanine-amino acid cross-linked oligonucleotide product. Analogous products were generated by photoionizing the free nucleoside, 2',3',5'-tri-O-acetylguanosine, (tri-O-Ac-Guo), using intense nanosecond 266 nm Nd:YAG laser pulse irradiation. The guanine-amino acid cross-links thus produced site-specifically positioned either in oligonucleotides, or in the free nucleoside tri-O-Ac-Guo were isolated by HPLC methods and identified by high resolution LC-TOF/MS and LC-MS/MS methods. The possibility that analogous guanine-amino acid cross-linked products could be formed in vivo using single hit radical generation mechanisms during oxidative stress is discussed.
Yuriy Uvaydov; Nicholas E Geacintov; Vladimir Shafirovich
Related Documents :
17263468 - Antioxidant contents and antioxidative properties of traditional rye breads.
16658778 - Phenolic acids in wheat coleoptile cell walls.
19922238 - Gastro-intestinal sustained release of phytic acid by molecularly imprinted micropartic...
2690858 - Occurrence and content of hydroxycinnamic and hydroxybenzoic acid compounds in foods.
15349698 - Modification of humic acids by the compost-dwelling deuteromycete paecilomyces inflatus.
24719358 - Plasma membrane phospholipase a2 controls hepatocellular fatty acid uptake and is respo...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2014-5-9
Journal Detail:
Title:  Physical chemistry chemical physics : PCCP     Volume:  -     ISSN:  1463-9084     ISO Abbreviation:  Phys Chem Chem Phys     Publication Date:  2014 May 
Date Detail:
Created Date:  2014-5-9     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100888160     Medline TA:  Phys Chem Chem Phys     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Stroke/thromboembolism and intracranial hemorrhage in a 'real world' atrial fibrillation population:...
Next Document:  Fitness Impact and Stability of a Transgene Conferring Resistance to Dengue-2 Virus following Introg...