Nial Partha S, Sathyaseelan Chakkarai, Bhanjadeo Madhabi M, Tulsiyan Kiran D, Rathinavelan Thenmalarchelvi, Subudhi Umakanta
DNA Nanomaterials & Application Laboratory, Environment and Sustainability Department, CSIR-Institute of Minerals & Materials Technology, Bhubaneswar 751 013, India.
Academy of Scientific & Innovative Research (AcSIR), Ghaziabad 201002, India.
ACS Omega. 2024 Nov 16;9(47):46784-46795. doi: 10.1021/acsomega.4c04562. eCollection 2024 Nov 26.
Rare earth elements have been shown to trigger the B-to-Z DNA transition in diverse self-assembled branched DNA architectures. Herein, we investigated the influence of cerium chloride on the conformational changes of DNA sequences containing repeated cytosine-guanine (CG) or guanine-cytosine (GC) sequences. The CD results show that (CG) repeats were susceptible to the formation of Z-DNA at low concentrations of CeCl. On the other hand, (GC) is unable to undergo B-Z DNA transition and instead exhibits condensation with a similar amount of CeCl. The CD signature was found to be different and unique in both alternate repeats during the interaction with CeCl. The sequence-specific effects on the B-Z transition are based on the order of nucleotides in DNA. With the addition of EDTA, the Z-form of DNA is reverted to the native B-form. Further, we have reported the positive zeta potential of CeCl-induced Z-DNA in contrast to the negative zeta potential of B-DNA. The differential zeta-potential value during the B-Z transition is complementary to the conformational changes of DNA. The molecular simulation study also supports the sequence-specific conformational change between the B- and Z-forms of DNA molecules. This newly described reversible topological and sequence-dependent transition is crucial for understanding the structural and biological roles of Z-DNA in response to CeCl.
稀土元素已被证明能在多种自组装分支DNA结构中引发B型到Z型的DNA转变。在此，我们研究了氯化铈对含有重复胞嘧啶-鸟嘌呤（CG）或鸟嘌呤-胞嘧啶（GC）序列的DNA序列构象变化的影响。圆二色性（CD）结果表明，在低浓度氯化铈条件下，（CG）重复序列易于形成Z-DNA。另一方面，（GC）序列无法发生B-Z DNA转变，而是在相同量的氯化铈作用下发生凝聚。在与氯化铈相互作用过程中，发现这两种交替重复序列的CD特征是不同且独特的。对B-Z转变的序列特异性影响基于DNA中核苷酸的顺序。加入乙二胺四乙酸（EDTA）后，DNA的Z型会恢复为天然的B型。此外，我们报道了氯化铈诱导的Z-DNA具有正的zeta电位，而B-DNA具有负的zeta电位。B-Z转变过程中的差异zeta电位值与DNA的构象变化互补。分子模拟研究也支持了DNA分子B型和Z型之间的序列特异性构象变化。这种新描述的可逆拓扑和序列依赖性转变对于理解Z-DNA在响应氯化铈时的结构和生物学作用至关重要。
