The late-stage site-specific functionalisation of peptides and proteins via polyoxometalate-mediated H-atom abstraction

通过多金属氧酸盐介导的 H 原子提取对肽和蛋白质进行后期位点特异性功能化

• 批准号: 1949162
• 金额: --
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1949162
• 关键词: late; stage; site; specific; functionalisation

Problems and importance:The last two decades have witnessed an increase in the regulatory approval of protein-based therapeutic and diagnostic agents. The unparalleled affinity and selectivity with which proteins bind to their target, ensures that such 'biologics' can be employed efficaciously for medical use. Additionally, the application of native proteins to the treatment of disease enables the development of therapeutics which may exhibit fewer side effects and thus reduced toxicity. Within oncology especially, protein-based biologics have stepped to the forefront of cancer diagnosis and treatment. However, despite advances within this field, safer and more efficacious approaches are actively sought. Functionalising clinically relevant protein sequences with imaging agents or cytotoxic compounds further enhances their therapeutic application and has led to significant interest in protein modification techniques. The development of efficient, chemoselective and generally applicable bioconjugation chemistry will enable the production of more advanced biologic agents which may ultimately have a substantial impact in the clinic.Relevance to sustainability:Despite the development of several site-specific protein modification techniques, the most utilised reactions to-date target cysteine residues, which are integral to protein structure and function, or lysine, the abundance of which causes the production of heterogeneously modified isoforms. Alternative techniques that do not make use of native residues may employ non-standard amino acids, a strategy that involves directed evolution of the relevant biologically machinery. Semi-synthetic techniques involving chemically synthesised peptides have also been widely utilised, however, such methods employ toxic reagents and use large quantities of solvent which limits the sustainability of this approach. The development of an efficient and mild site-selective bioconjugation reaction that could be broadly applied to any biologically expressed protein sequence, targeting native residues that are not integral to protein structure and function, would be a highly impactful advance. Proposed solution and methodologyWe propose the development of a strategy for the late-stage site-specific functionalisation of peptides and proteins utilising radical chemistry. Polyoxometalate (POM) clusters have previously been reported to enable H-atom abstraction from unactivated aliphatic tertiary centres, facilitating the fluorination of selected amino acids. We wish to further explore this POM-mediated strategy, expanding the scope of the approach to enable the broader functionalisation of peptides and proteins in a site-selective manner. By combining this H-atom abstraction method with a small library of modified radical traps, we aim to install desired functionality (e.g. radioactive nuclides or cytotoxic compounds) at the site of radical formation on several amino acid residues. Starting with a simple decatungstate cluster, we will explore and utilise the tunable properties of the POM to increase control and site-selectivity. The reaction will be mild, proceeding rapidly in an aqueous solution, requiring only catalytic addition of the POM. Our strategy will be tailored to enable the introduction of a toolbox of functionality which could be applied to any chosen protein. Ultimately, we will seek to employ our technique to functionalise proteins that target receptors expressed by highly invasive triple-negative breast cancer.

问题和重要性：在过去的二十年里，基于蛋白质的治疗和诊断药物的监管批准有所增加。蛋白质与其目标结合的无与伦比的亲和力和选择性确保了这种“生物制剂”可以有效地用于医疗用途。此外，天然蛋白质在疾病治疗中的应用使得能够开发可表现出较少副作用并因此降低毒性的治疗剂。特别是在肿瘤学领域，基于蛋白质的生物制剂已经走到了癌症诊断和治疗的最前沿。然而，尽管在该领域内取得了进展，但仍在积极寻求更安全和更有效的方法。用成像剂或细胞毒性化合物使临床相关蛋白质序列官能化进一步增强了它们的治疗应用，并引起了对蛋白质修饰技术的极大兴趣。高效的，化学选择性和普遍适用的生物共轭化学的发展将使生产更先进的生物制剂，最终可能在clinic.Relevance产生重大影响的可持续性：尽管发展的几个特定位点的蛋白质修饰技术，最利用的反应迄今目标半胱氨酸残基，这是不可或缺的蛋白质结构和功能，或赖氨酸，丰富的，其中导致生产的异质性修改异构体。不利用天然残基的替代技术可以采用非标准氨基酸，这是一种涉及相关生物机制的定向进化的策略。涉及化学合成肽的半合成技术也已被广泛使用，然而，此类方法使用有毒试剂并使用大量溶剂，这限制了该方法的可持续性。开发一种有效和温和的位点选择性生物缀合反应，可以广泛应用于任何生物表达的蛋白质序列，靶向不是蛋白质结构和功能不可或缺的天然残基，这将是一个非常有影响力的进步。提出的解决方案和方法我们提出了一个战略的发展，为后期的肽和蛋白质的位点特异性功能化利用自由基化学。聚氧乙烯酸酯（POM）簇先前已被报道，使H-原子的抽象从未活化的脂肪族叔中心，促进选定的氨基酸的取代。我们希望进一步探索这种POM介导的策略，扩大该方法的范围，以使肽和蛋白质以位点选择性方式更广泛地功能化。通过将这种H原子提取方法与一个小的改性自由基陷阱库相结合，我们的目标是在几个氨基酸残基上的自由基形成位点处安装所需的功能性（例如放射性核素或细胞毒性化合物）。从一个简单的十聚钨酸盐簇开始，我们将探索和利用POM的可调特性来增加控制和位点选择性。反应将是温和的，在水溶液中快速进行，仅需要催化添加POM。我们的策略将是量身定制的，以便能够引入可应用于任何选定蛋白质的功能工具箱。最终，我们将寻求利用我们的技术来功能化靶向高度侵袭性三阴性乳腺癌表达的受体的蛋白质。