Acta Chimica Sinica ›› 2022, Vol. 80 ›› Issue (4): 444-452.DOI: 10.6023/A21120580 Previous Articles     Next Articles

Article

蝎子毒素多肽WaTx的高效化学合成及氧化折叠研究

尹昊a,c, 陈西同a,c, 付邢言a,c, 马艳楠a,c, 徐以梅a,c, 张特a,c, 梁帅a,c, 杜姗姗b,*(), 齐昀坤a,c,*(), 王克威a,c   

  1. a 青岛大学药学院 山东青岛 266073
    b 青岛科技大学化工学院 山东青岛 266042
    c 青岛大学创新药物研究院 山东青岛 266021
  • 投稿日期:2021-12-24 发布日期:2022-02-17
  • 通讯作者: 杜姗姗, 齐昀坤
  • 作者简介:
    † 共同第一作者
  • 基金资助:
    国家自然科学基金(21807063); 国家自然科学基金(82003647); 国家自然科学基金(22177058); 国家自然科学基金(81870653)

Efficient Chemical Synthesis and Oxidative Folding Studies of Scorpion Toxin Peptide WaTx

Hao Yina,c, Xitong Chena,c, Xingyan Fua,c, Yannan Maa,c, Yimei Xua,c, Te Zhanga,c, Shuai Lianga,c, Shanshan Dub(), Yunkun Qia,c(), Kewei Wanga,c   

  1. a School of Pharmacy, Qingdao University, Qingdao, Shandong 266073
    b College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao, Shandong 266042
    c Institute of Innovative Drugs, Qingdao University, Qingdao, Shandong 266021
  • Received:2021-12-24 Published:2022-02-17
  • Contact: Shanshan Du, Yunkun Qi
  • About author:
    † These authors contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(21807063); National Natural Science Foundation of China(82003647); National Natural Science Foundation of China(22177058); National Natural Science Foundation of China(81870653)

Coupling or condensation reagents that could be used to promote the condensation of carboxylic acids with amines to furnish amide bonds play crucial roles in solid phase peptide synthesis (SPPS) of peptides and peptide-based derivatives. Compared with traditional coupling reagents used in SPPS such as 1-hydroxy-7-azabenzotriazole (HOAt) and 1-hydroxybenzotriazole (HOBt), the novel N,N'-diisopropylcarbodiimide (DIC)/ethyl 2-cyano-2-(hydroxyimino) acetate (Oxyma) condensation system has advantages of inexpensiveness, safety, high coupling efficiency, low racemic rate, and compatibility with manual and automatic peptide synthesis represented by microwave-assisted SPPS. However, the effects of different reaction temperatures (e.g. 28, 50, and 75 ℃) on the coupling efficiency of DIC/Oxyma and on the easily oxidized amino acids such as methionine (Met) remain to be further investigated. The transient receptor potential ankyrin 1 (TRPA1) channel plays an important role in temperature perception, auditory perception, and inflammatory pain. As a novel non-covalently TRPA1-specific agonist, Wasabi Receptor Toxin (WaTx) that consists of 33 amino acid residues and two pairs of disulfide bonds is considered as an important molecular tool to study the opening mechanism and function of TRPA1. In this study, 2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminiumhexa-fluorophosphate (HCTU)/N,N'-diisopropyl- ethylamine (DIEA) and DIC/Oxyma condensation systems were separately utilized to explore the synthetic efficiency of linear WaTx and the oxidative degree of Met residues at different temperatures. The robustness of DIC/Oxyma condensation system was validated by the rapid manual synthesis of linear WaTx. The one-step and two-step oxidative folding strategies were separately applied for the construction of two pairs of disulfide bridges, affording the active WaTx, which was further confirmed by circular dichroism and calcium fluorescence assay. In this study, a moderate, efficient synthesis and renaturation folding method of WaTx was established. Moreover, the effects of different reaction temperatures on the synthetic efficiency of DIC/Oxyma and on amino acid residues oxidization were compared for the first time. From the aspects of reaction efficiency (represented by the timescale of the overall Fmoc deprotection-washing-amino acid coupling SPPS cycle), amino acid residues oxidization and synthetic cost, n(Fmoc-amino acid):n(DIC):n(Oxyma)=3:6:3 under 50 ℃ should be the ideal reaction condition. This work provides both an imperative complement for SPPS and a particularly useful strategy for the manual efficient synthesis of disulfide-containing peptides with easily oxidized groups.

Key words: N,N'-diisopropylcarbodiimide (DIC), oxyma, solid phase peptide synthesis, disulfide bond, oxidative folding, Wasabi Receptor Toxin (WaTx), peptide toxin