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）：在确定金属霉素（MBLMS）与DNA的结合模式特征中存在基本差距。该差距代表了一个重要的问题，因为参与BLM的DNA结合的药物的C-末端取代基（Tails）也已被确定为归因于BLM的肺毒性的关键因素。因此，此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方法可以通过一种可以分开影响它的各种因素的方法来更好地理解生物学相关的MBLM与DNA的结合，并着重于这种结合对BLM的尾巴的影响，从而产生不同水平的肺纤维化。该特定应用的目的是确定BLM尾巴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的肺毒性的尾巴。中心假设是，具有不同化学结构的BLM尾巴会以特定方式与DNA中的原子相关，并生成相应MBLM-DNA复合物的（C-末端） - DNA区域的不同溶液结构。我们基于初步发现提出了这一假设，该发现表明BLM尾巴可以将MBLM锚定在DNA上，并影响药物的其余C-末端位于DNA螺旋中的方式。拟议的研究的理由是，评估提议引起各种肺纤维化的DNA结合模式在小鼠中将有两个目的：1）更好地建立MBLM和DNA之间的分子识别的结构基础，以及2），以帮助分解这些药物的结构/毒性相关性。在强有力的初步数据的指导下，将通过追求两个特定目的来检验该假设：1）使用两个不同的DNA片段在溶液中识别MBLM和DNA之间的相互作用，每个片段包含特定的BLM结合位点，以及具有不同结构和毒性的尾巴的相关MBLM； 2）表征BLM尾部通过所考虑的MBLM-DNA复合物的分子建模在MBLM和DNA之间的结构相互作用中的影响。在第一个目标下，将NMR光谱应用于顺磁分子（例如生物学相关的MBLM（FEIIBLMS）），将用于鉴定所考虑的MBLM和DNA之间的原子 - 原子接触。在第二个目标下，将使用分子动力学计算来找到所考虑的MBLM-DNA复合物的溶液结构。在申请人的手中已确定这种方法是可行的。拟议的研究具有创新性，因为它仅考虑生物学相关的MBLM，由于其顺磁性，从结构的角度看不到足够的关注，并且隔离了影响BLM的DNA结合的因素。这项贡献将是重要的，因为它有望从结构的角度垂直提高和扩展对毒性的理解，以指导BLM类似物的发展，对癌症患者的副作用较轻。

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