Role of the bleomycin C-termini in DNA binding and toxicity by metallo-bleomycins

博莱霉素 C 末端在 DNA 结合和金属博莱霉素毒性中的作用

• 批准号: 8688723
• 负责人: Teresa E Lehmann
• 金额: $ 29.77万
• 依托单位: UNIVERSITY OF WYOMING
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8688723
• 关键词: Adverse effects; Affect; Affinity; Antibiotics; Antineoplastic Agents; Area; Attention; Base Sequence; Binding; Binding Sites; Bleomycin; Cancer Etiology; Cancer Patient; Characteristics; Chemical Structure; Chemistry; Cleaved cell; Complex; Consensus; DNA; DNA Binding; Data; Development; Drug usage; Electrostatics; Elements; Exhibits; Family; Goals; Hand; Health; Human; Hydrogen Bonding; Knowledge; Lead; Link; Lung; Malignant Neoplasms; Metal Binding Site; Metals; Modeling; Molecular Models; Mus; NMR Spectroscopy; Nature; Patients; Pharmaceutical Preparations; Positioning Attribute; Public Health; Pulmonary Fibrosis; Research; Rest; Role; Signal Transduction; Site; Solutions; Structure; Tail; Testing; Toxic effect; Work; analog; antineoplastic antibiotics; base; burden of illness; career; graduate student; in vivo; indium-bleomycin; innovation; iron(II) bleomycin; knowledge base; molecular dynamics; molecular modeling; molecular recognition; public health relevance; receptor; undergraduate student

DESCRIPTION (provided by applicant): There is a fundamental gap in definitely establishing the binding mode characteristic of metallo-bleomycins (MBLMs) to DNA. This gap represents an important problem, since the drugs' C-terminus substituents (tails), which participate on DNA binding by BLM, have also been identified as key factors in the pulmonary toxicity attributed to BLMs. Therefore, this gap hinders the understanding of structure/toxicity correlations for these anticancer drugs. The long-term goal is to better understand the binding of biologically relevant MBLMs to DNA, through an approach that can separate the various factors that affect it, and focusing on the impact of the tails in this binding for BLMs producing different levels of pulmonary fibrosis. The objective in this particular application is to determine how the chemical structures of the BLM tails influence structural interactions between FeIIBLM and DNA, independently of the DNA base sequence, and considering tails with different degrees of pulmonary toxicity. The central hypothesis is that BLM tails with different chemical structures wil correlate with the atoms in DNA in specific ways, and generate different solution structures of the (C-terminus)- DNA regions for the corresponding MBLM-DNA complexes. We have formulated this hypothesis based upon preliminary findings that suggest that the BLM tail can anchor MBLM to DNA, and affect the way in which the rest of the C-terminus of the drug is positioned in the DNA helix. The rationale for the proposed research is that assessing the DNA-binding modes BLMs proposed to cause various levels of pulmonary fibrosis in mice will serve two purposes: 1) to better establish the structural basis for molecular recognition between MBLM and DNA, and 2) to help delineate structure/toxicity correlations for these drugs. Guided by strong preliminary data, this hypothesis will be tested by pursuing two specific aims: 1) Identify interactions between MBLM and DNA in solution using two distinct DNA segments, each containing a specific BLM binding site, and relevant MBLMs with tails with different structures and toxicities; and 2) Characterize the effect of the BLM tail in the structural interactions between MBLM and DNA through molecular modeling of the MBLM-DNA complexes considered. Under the first aim, NMR spectroscopy applied to paramagnetic molecules such as the biologically relevant MBLMs (FeIIBLMs), will be used to identify atom-atom contacts between the MBLMs considered and DNA. Under the second aim, molecular dynamics calculations will be used to find the solution structures of the MBLM-DNA complexes considered. This approach has been established as feasible in the applicant's hands. The proposed research is innovative because it only considers biologically relevant MBLMs, which have no received sufficient attention from the structural point of view due to their paramagnetic nature, and it isolates the factors affecting DNA binding by BLMs. This contribution will be significant because it is expected to vertically advance and expand the understanding of toxicity from the structural point of view, required to guide the development of BLM analogs with milder side effects for cancer patients.

描述（由申请人提供）：在明确建立金属博来霉素（MBLM）与DNA的结合模式特征方面存在根本性的差距。这种差距代表了一个重要的问题，因为参与 BLM 的 DNA 结合的药物 C 末端取代基（尾部）也被认为是 BLM 引起的肺毒性的关键因素。因此，这一差距阻碍了对这些抗癌药物的结构/毒性相关性的理解。长期目标是通过一种可以分离影响它的各种因素的方法，更好地了解生物学相关的 MBLM 与 DNA 的结合，并重点关注尾部在这种结合中对产生不同水平肺纤维化的 BLM 的影响。此特定应用的目的是确定 BLM 尾部的化学结构如何影响 FeIIBLM 和 DNA 之间的结构相互作用，独立于 DNA 碱基序列，并考虑具有不同程度肺毒性的尾部。中心假设是具有不同化学结构的 BLM 尾部将以特定方式与 DNA 中的原子相关联，并为相应的 MBLM-DNA 复合物生成不同的（C 末端）-DNA 区域溶液结构。我们根据初步发现制定了这一假设，初步发现表明 BLM 尾部可以将 MBLM 锚定到 DNA 上，并影响药物 C 末端其余部分在 DNA 螺旋中的定位方式。拟议研究的基本原理是，评估导致小鼠不同程度肺纤维化的 BLM 的 DNA 结合模式将有两个目的：1）更好地建立 MBLM 和 DNA 之间分子识别的结构基础，2）帮助描述这些药物的结构/毒性相关性。在强有力的初步数据的指导下，该假设将通过追求两个具体目标进行检验：1) 使用两个不同的 DNA 片段（每个片段包含特定的 BLM 结合位点）以及具有不同结构和尾部的相关 MBLM 来识别溶液中 MBLM 和 DNA 之间的相互作用。毒性； 2) 通过对所考虑的 MBLM-DNA 复合物进行分子建模，表征 BLM 尾部在 MBLM 和 DNA 之间的结构相互作用中的影响。第一个目标是，将核磁共振波谱应用于顺磁性分子，例如生物学相关的 MBLM (FeIIBLM)，将用于识别所考虑的 MBLM 与 DNA 之间的原子-原子接触。在第二个目标下，分子动力学计算将用于找到所考虑的 MBLM-DNA 复合物的溶液结构。该方法在申请人手中已被确定为可行。所提出的研究具有创新性，因为它只考虑了生物学相关的MBLM，而由于其顺磁性，从结构角度来看，MBLM并未受到足够的关注，并且它分离出了影响BLM与DNA结合的因素。这一贡献将是意义重大的，因为它有望从结构的角度垂直推进和扩大对毒性的理解，从而指导开发对癌症患者副作用较轻的 BLM 类似物。

项目成果

Structural changes of Zn(II)bleomycin complexes when bound to DNA hairpins containing the 5'-GT-3' and 5'-GC-3' binding sites studied through NMR spectroscopy.

通过 NMR 光谱研究了 Zn(II) 博莱霉素复合物与含有 5-GT-3 和 5-GC-3 结合位点的 DNA 发夹结合时的结构变化。

• DOI: 10.3390/magnetochemistry4010004
• 发表时间: 2018
• 期刊: Magnetochemistry (Basel, Switzerland)
• 作者: Follett,ShelbyE;Murray,SallyA;Ingersoll,AzureD;Reilly,TeresaM;Lehmann,TeresaE
• 通讯作者: Lehmann,TeresaE