BORON-CONTAINING OLIGODEOXYRIBONUCLEOTIDE 14MER DUPLEXES - ENZYMATIC-SYNTHESIS AND MELTING STUDIES
BORON-CONTAINING OLIGODEOXYRIBONUCLEOTIDE 14MER DUPLEXES - ENZYMATIC-SYNTHESIS AND MELTING STUDIES
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DOI：
10.1093/nar/23.21.4495
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发表时间：
1995-11-11
影响因子：
14.9
通讯作者：
SHAW, BR
中科院分区：
文献类型：
--
作者：
LI, H;PORTER, K;SHAW, BR
一组三个序列为d的14聚体寡脱氧核糖核苷酸（5 '-CTATGGCCTCAG*CT-3/3'-GATACCGGAGTCGA 5 '），其含有G* 变体，作为2'-脱氧鸟苷磷酸（未修饰），N7-氰基硼烷2 '-脱氧鸟苷磷酸（碱基修饰）或5 '-脱氧鸟苷硼磷酸（主链修饰的）通过模板指导的引物延伸合成，N7-氰基硼烷5 '-脱氧鸟苷三磷酸和2'-脱氧鸟苷α-硼三磷酸核苷酸都是测序酶的良好底物，我们推断一个单一的S-p硼磷酸键（其立体化学等同于相应的R（p）硫代磷酸酯类似物）在主链修饰的14聚体中形成，使用UV和圆二色性（CD）光谱监测杂交双链体的热诱导螺旋-卷曲转变。两种类型的硼修饰的杂交体的CD光谱与未修饰的亲本双链体非常相似，在150 mM NaCl、1 mM EDTA、10 mM磷酸盐、pH 7.4缓冲液中形成B型螺旋，UV熔解结果表明，两种杂交体具有与亲本双链体相当的稳定性，如通过T-m或Δ G度测量的（25）。这些研究表明，单修饰的碱基或骨架硼化DNA是正常DNA的良好类似物。
A set of three 14mer oligodeoxyribonucleotides of sequence d(5'-CTATGGCCTCAG*CT-3/3'-GATACCGGAGTCGA5') containing G* variants either as 2'-deoxyguanosine phosphate (unmodified), N7-cyanoborane 2'-deoxyguanosine phosphate (base-modified) or 5'-deoxyguanosine boranophosphate (backbone-modified) were synthesized by template-directed primer extension, Both the N7-cyanoborane 5'-deoxyguanosine triphosphate and 2'-deoxyguanosine alpha-boranotriphosphate nucleotides are good substrates for Sequenase, We infer that a single S-p boranophosphate linkage (which has a stereochemistry equivalent to the corresponding R(p) thiophosphate analog) is formed in the backbone-modified 14mer, Thermally induced helix-coil transitions were monitored for the hybridized duplexes using UV and circular dichroism (CD) spectroscopy, The CD spectra of the two types of boron-modified hybrids closely resemble the unmodified parent duplex, forming B-type helices in 150 mM NaCl, 1 mM EDTA, 10 mM phosphate, pH 7.4, buffer, UV melting results indicate that both hybrids have stabilities comparable with the parent duplex as measured by T-m or Delta G degrees(25). These studies indicate that singly modified base- or backbone-boronated DNA are good analogs of normal DNA.