Less is More:Design of a Highly Stable Disulfide-Deleted Mutant of Analgesic Cyclic α-Conotoxin Vc1.

• 作 者: RileiYu[1]VictoriaA.L.Seymour[2]GézaBerecki[2]XinyingJia[3]MuharremAkcan[4]DavidJ.Adams[2]QuentinKaas[5]DavidJ.Craik[5]
• 机 构: Institute for Molecular Bioscience,The University of Queensland,Brisbane,Queensland,4072,Australia
• 出 处: 第八届国际分子模拟与信息技术应用学术会议
• 发表日期: 2016年期

　　Cyclic α-conotoxin Vc1.1(cVc1.1)is an orally active peptide with analgesic activity in rat models of neuropathic pain.It has two disulfide bonds,which can have three different connectivities,one of which is the native and active form.In this study we used computational modeling and nuclear magnetic resonance to design a disulfide-deleted mutant of cVc1.1,[C2H,C8F]cVc1.1,which has a larger hydrophobic core than cVc1.1 and,potentially,additional surface salt bridge interactions.The new variant,hcVc1.1,has similar structure and serum stability to cVci.i and is highly stable at a wide range of pH and temperatures.Remarkably,hcVc1.1 also has similar selectivity to cVc1.1,as it inhibited recombinant human αgα10 nicotinic acetylcholine receptor-mediated currents with an IC50 of 13μM and rat N-type(Cav2.2)and recombinant human Cav2.3 calcium channels via GABAB receptor activation,with an IC50 of-goo pM.Compared to cVc1.1,the potency of hcVc1.1 is reduced three-fold at both analgesic targets,whereas previous attempts to replace Vc1.1 disulfide bonds by non-reducible dicarba linkages resulted in at least 30-fold decreased activity.Because it has only one disulfide bond,hcVc1.1 is not subject to disulfide bond shuffling and does not form multiple isomers during peptide synthesis.