Spears Richard J, Brabham Robin L, Budhadev Darshita, Keenan Tessa, McKenna Sophie, Walton Julia, Brannigan James A, Brzozowski A Marek, Wilkinson Anthony J, Plevin Michael, Fascione Martin A
Department of Chemistry , University of York , York , YO10 5DD , UK . Email:
Department of Biology , University of York , York , YO10 5DD , UK.
Chem Sci. 2018 May 31;9(25):5585-5593. doi: 10.1039/c8sc01617h. eCollection 2018 Jul 7.
The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing biological mechanisms. The general use of chemical methods for protein functionalisation can be limited however by the requirement for complicated reaction partners to be present in large excess, and harsh conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH. OPAL enables rapid modification of proteins using simple aldehyde probes in minimal excess, and is utilised here in the affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the β-hydroxy aldehyde OPAL product can be functionalised again at neutral pH in a tandem organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the 'chemical mimicry' of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis.
蛋白质与小分子的生物共轭已被证明是一种用于探究和干扰生物机制的宝贵策略。然而，化学方法用于蛋白质功能化的普遍应用可能会受到限制，这是因为需要大量过量存在复杂的反应伙伴，以及与许多蛋白质支架不相容的苛刻条件。在此，我们描述了一种位点选择性有机催化剂介导的蛋白质醛醇连接反应（OPAL），该反应能在中性pH条件下提供稳定的碳-碳连接的生物共轭物。OPAL能够使用少量过量的简单醛探针快速修饰蛋白质，并在此用于细胞裂解物中蛋白质的亲和标记。此外，我们证明β-羟基醛OPAL产物可以在中性pH条件下通过串联有机催化剂介导的肟连接反应再次进行功能化。这种串联策略在一种先前无法获得的天然双翻译后修饰蛋白质的“化学模拟”中得到了展示，该蛋白质是被忽视的热带疾病利什曼病发病机制所必需的。
