Base Pairing and Replicative Processing of the Formamidopyrimidine-dG DNA Lesion
摘要:
The 2,6-diamino-4-hydroxy-5-formamidopyrimidine of 2'-deoxyguanosine (FaPydG) is one of the major DNA lesions found after oxidative stress in cells. To clarify the base pairing and coding potential of this major DNA lesion with the aim to estimate its mutagenic effect, we prepared oligonucleotides containing a cyclopentane based analogue of the DNA lesion (cFaPydG). In addition, oligonucleoticles containing the cyclopentane analogue of 2'-deoxyguanosine (cdG), and oligonucleotides containing 8-oxo-7,8-dihydro2'-deoxyguanosine (8-oxodG) were synthesized. The thermodynamic stability of duplexes containing these building blocks and all canonical counterbases were determined by concentration dependent melting-point measurements (van't Hoff plots). The data reveal that cFaPydG greatly destabilizes a DNA duplex (Delta Delta G(o)298K approximate to 2-4 kcal mol(-1)). The optimal base pairing partner for the cFaPydG lesion is dC. Investigation of duplexes containing dG and cdG shows that the effect of substituting the deoxyribose by a cyclopentane moiety is marginal. The data also provide strong evidence that the FaPydG lesion is unable to form a base pair with dA. Our computational studies indicate that the syn-conformation required for base pairing with dA is energetically unfavorable. This is in contrast to 8-oxodG for which the syn-conformation represents the energetic minimum. Kinetic primer extension studies using S. cerevisiae Pol eta reveal that cFaPydG is replicated in an error-free fashion. dC is inserted 2-3 orders of magnitude more efficiently than dT or CIA, showing that FaPydG is a lesion which retains the coding potential of dG. This is also in contrast to 8-oxodG, for which base pairing with dC and dA was established.
METHOD FOR SYNTHESIZING SAPROPTERIN DIHYDROCHLORIDE
申请人:ASYMCHEM LABORATORIES (TIANJIN)CO., LTD.
公开号:US20150119573A1
公开(公告)日:2015-04-30
Disclosed is a method for synthesizing sapropterin dihydrochloride. The present disclosure reduces a synthesis route of the sapropterin dihydrochloride, and resolves a racemate intermediate or an intermediate having a low antimer isomerism value by using a chiral resolving reagent, thereby obtaining an intermediate having a high antimer isomerism value. Raw materials are cheap and readily available, and the cost is significantly reduced, hence providing an effective scheme for mass industrial production of the sapropterin dihydrochloride.
Synthesis of a nitro group containing ribonucleoside related to guanosine
作者:J. Claude Espie、M. France Lhomme、Claude Morat、Jean Lhomme
DOI:10.1016/s0040-4039(00)88822-x
日期:1990.1
The α- and β-anomers of the nitrogroup containing ribonucleoside have been prepared in a three-step sequence. Both exhibit an intramolecular H-bond between the 4-NH and an oxygen atom of the nitrogroup.
Dissecting the Differences between the α and β Anomers of the Oxidative DNA Lesion FaPydG
作者:Florian Büsch、J. Carsten Pieck、Matthias Ober、Johannes Gierlich、Gerald W. Hsu、Lorena S. Beese、Thomas Carell
DOI:10.1002/chem.200701373
日期:2008.2.27
The oxidativeDNAlesion, FaPydG rapidly anomerizes to form a mixture of the alpha and beta anomer. To investigate the mutagenic potential of both forms, we prepared stabilized bioisosteric analogues of both configurational isomers and incorporated them into oligonucleotides. These were subsequently used for thermodynamic melting-point studies and for primer-extension experiments. While the beta compound
氧化性DNA损伤FaPydG迅速发生异构化,形成α和β异构体的混合物。为了研究两种形式的诱变潜力,我们制备了两种构型异构体的稳定的生物等位基因类似物,并将其掺入寡核苷酸中。这些随后被用于热力学熔点研究和引物延伸实验。尽管与早期数据一致,β化合物更喜欢使用胞苷作为配对伴侣,但α化合物不能与任何天然碱基形成稳定的碱基对。在使用高保真聚合酶Bst Pol I进行引物延伸研究中,该聚合酶能够读取病灶。β化合物没有显示出很强的诱变潜力。相比之下,α化合物会严重破坏DNA双链体的稳定性,并会阻断所有测试的DNA聚合酶,
Synthesis of the riboside analog of the pyrimidine adduct formed in the reaction between the carcinogen n-hydroxy-n-2 acetylaminofluorene and DNA
作者:B. Robillard、M.F. Lhomme、J. Lhomme
DOI:10.1016/s0040-4039(00)98129-2
日期:1985.1
A general synthesis has been achieved to obtain carcinogen modified quanosines. The method was applied to the preparation of the N- 2, 5-diamino-4-oxo-3H-pyrimidine-6-yl-N-(β-D-ribofuranosyl)-N(2-fluorenyl)urea .