Maxwell Joshua W C, Ripoll-Rozada Jorge, Mackay Angus S, Alwis Imala, Ford Daniel J, Trought Cameron B J, Santos Joana A, Smythe Rhyll E, Liu Joanna S T, Zuccolotto Zack, Schoenwaelder Simone M, Jackson Shaun P, Pereira Pedro José Barbosa, Payne Richard J
School of Chemistry, Faculty of Science, The University of Sydney NSW Australia
Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney Sydney NSW 2006 Australia.
Chem Sci. 2025 Sep 1. doi: 10.1039/d5sc04734j.
Haematophagous organisms are a rich source of salivary anticoagulant polypeptides that exert their activity by blocking the catalytic site and one of two positively charged exosites on the host protease thrombin. Here, we describe a molecular engineering approach to hybridise post-translationally sulfated polypeptides from different blood-feeding organisms to enhance anticoagulant activity. This led to the discovery of a triply sulfated hybrid anticoagulant, XChimera, possessing fragments from flea, leech, and fly salivary polypeptides that exhibits femtomolar inhibitory activity against thrombin. The crystallographic structure of a complex of XChimera with thrombin shows that it displays a trivalent binding mode in which it simultaneously blocks three functional sites of the protease, the active site and exosites I and II. This trivalent chimera exhibited ultrapotent anticoagulant activity in a suite of clotting assays and was also shown to possess potent antithrombotic activity in a murine model of thrombosis.
吸血生物是唾液抗凝多肽的丰富来源，这些多肽通过阻断宿主蛋白酶凝血酶的催化位点和两个带正电荷的外位点之一来发挥其活性。在此，我们描述了一种分子工程方法，用于将来自不同吸血生物的翻译后硫酸化多肽进行杂交，以增强抗凝活性。这导致发现了一种三重硫酸化的杂交抗凝剂XChimera，它具有来自跳蚤、水蛭和苍蝇唾液多肽的片段，对凝血酶表现出飞摩尔级的抑制活性。XChimera与凝血酶复合物的晶体结构表明，它呈现出一种三价结合模式，即同时阻断蛋白酶的三个功能位点，即活性位点以及外位点I和II。这种三价嵌合体在一系列凝血试验中表现出超强的抗凝活性，并且在血栓形成的小鼠模型中也显示出强大的抗血栓活性。
