DNA interchain cross-links formed by acrolein and crotonaldehyde
DNA interchain cross-links formed by acrolein and crotonaldehyde
复制标题
DOI：
10.1021/ja020778f
复制
发表时间：
2003-01-08
影响因子：
15
通讯作者：
Harris, TM
中科院分区：
文献类型：
--
作者：
Kozekov, ID;Nechev, LV;Harris, TM
丙烯醛和高级α，β-不饱和醛是双功能基因毒素。丙烯醛的脱氧鸟苷加合物，3-（2-deoxy-beta-D-propanofuranosyl）-5，6，7，8-tetrahydro-8-hydroxypyrimido[1，2-a]purin-10（3 H）-one（8-hydroxy-1，N-2-propanodeoxyguanosine，2a），是由丙烯醛形成的主要DNA加合物。通过HPLC、CZE、MALDI-TOF和熔解现象评价了含有2a的寡脱氧核苷酸双链体形成链间交联的潜力。链间交联是DNA中最严重的损伤类型之一，因为它们是复制的绝对障碍。在含有序列5 '-dC-2a的寡脱氧核苷酸中，交联以缓慢、可逆的方式发生，交联程度接近50%。酶消化形成3-（2-脱氧-β-D-异丙基-戊呋喃糖基）-5，6，7，8-四氢-8-（N-2- 2 ′-脱氧鸟苷基）嘧啶并[1，2-a]嘌呤-10（3 H）酮（5a），用NaCNBH 3还原，然后酶消化得到1，3-双（2 ′-脱氧鸟苷-N-2-基）丙烷（6a），证实了与脱氧鸟苷的环外氨基发生了交联。结果表明，交联是亚胺和甲醇胺结构的混合物。对于含有序列5 '-2a_dC的寡脱氧核苷酸双链体，通过上述列举的技术未检测到交联。此外，用具有靶氨基的N-15-标记的双链体进行的N-15-H-1 HSQC和HSOC过滤的NOESY光谱明确确定未形成甲醇胺交联。在5 '-dC-2b序列中评估了类似巴豆醛加合物（2b）形成链间交联的可能性。交联形成强烈依赖于2b的C6处的甲基的构型。2b的6 R非对映异构体形成了38%程度的交联，而6S非对映异构体仅交联5%。
Acrolein and higher alpha,beta-unsaturated aldehydes are bifunctional genotoxins. The deoxyguanosine adduct of acrolein, 3-(2-deoxy-beta-D-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a]purin-10(3H)-one (8-hydroxy-1,N-2-propanodeoxyguanosine, 2a), is a major DNA adduct formed by acrolein. The potential for oligodeoxynucleotide duplexes containing 2a to form interchain cross-links was evaluated by HPLC, CZE, MALDI-TOF, and melting phenomena. Interchain cross-links represent one of the most serious types of damage in DNA since they are absolute blocks to replication. In oligodeoxynucleotides containing the sequence 5'-dC-2a, cross-linking occurred in a slow, reversible manner to the extent of similar to50%. Enzymatic digestion to form 3-(2-deoxy-beta-D-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-8-(N-2-2'-deoxyguanosinyl)pyrimido[1,2-a]purin-10(3H)one (5a) and reduction with NaCNBH3 followed by enzymatic digestion to give 1,3-bis(2'-deoxyguanosin-N-2-yl)propane (6a) established that cross-linking had occurred with the exocyclic amino group of deoxyguanosine. It is concluded that the cross-link is a mixture of imine and carbinolamine structures. With oligodeoxynucleotide duplexes containing the sequence 5'-2a-dC, cross-links were not detected by the techniques enumerated above. In addition, N-15-H-1 HSQC and HSOC-filtered NOESY spectra carried out with a duplex having N-15-labeling of the target amino group established unambiguously that a carbinolamine cross-link was not formed. The potential for interchain cross-link formation by the analogous crotonaldehyde adduct (2b) was evaluated in a 5'-dC-2b sequence. Cross-link formation was strongly dependent on the configuration of the methyl group at C6 of 2b. The 6R diastereomer of 2b formed a cross-link to the extent of 38%, whereas the 6S diastereomer cross-linked only 5%.