New class of anticoagulant found in tick saliva

Licensing opportunity

Maria Kazimirova from the Slovak Academy of Sciences and Patricia Nuttall’s team from the UK’s Centre for Ecology and Hydrology have isolated a thrombin inhibitor from the salivary glands of ticks, which they have called Variegin. Ticks secrete the anticoagulant to prevent their host’s blood flowing while they feed.

The researchers subsequently teamed up with experts in snake venom peptides from the National University of Singapore, who have developed a synthetic version of this naturally-occurring molecule, while optimising the properties to make it more potent. The Singapore researchers, Manjunatha Kini and Cho Yeow Koh also discovered that Variegin appears to be a new class of thrombin inhibitor, which may be more efficient and long-lasting than the direct thrombin inhibitors currently on the market.

Nuttall said that as well as enabling blood to flow freely, it may be possible to stop the effect so that clotting is restored. “This is an important breakthrough as it will potentially enable the development of new blood-controlling drugs with a much better performance level – and therefore fewer adverse side effects – than some of those currently available.”

Koh added, “We now have molecules with different sizes, potency and mechanism and duration of action, providing a solid platform for further development of an anti-clotting agent. One of them has 70 times more potency and long-lasting anti-clotting effect than a drug that is currently available in the market.”

The scientists have carried out initial tests on zebrafish to show that Variegin can prevent venous thrombosis.

The partners have filed patent applications and have drawn up a commercialisation agreement through the UK’s Natural Environment Research Council. The research council’s commercialisation and innovation team is now actively seeking commercial partners or licensing deals to take this forward.