糖肽是一類寡糖與多肽相結(jié)合的大分子化合物。糖肽在糖類藥物研發(fā)，如糖肽類抗生素和抗腫瘤疫苗的研發(fā)中有重要應(yīng)用。經(jīng)過幾十年的發(fā)展，多肽的合成技術(shù)目前已經(jīng)十分成熟，寡糖的合成在最近幾年也取得了進展。然而關(guān)于糖肽的合成，仍然是極具挑戰(zhàn)的難題。
Glycopeptides are a type of macromolecular compound that combines oligosaccharides with peptides. Glycopeptides have important applications in the development of carbohydrate drugs, such as glycopeptide antibiotics and anti-tumor vaccines. After decades of development, the synthesis technology of peptides is now very mature, and the synthesis of oligosaccharides has also made progress in recent years. However, the synthesis of glycopeptides remains a highly challenging problem.
近日，中國科學院上海藥物研究所文留青課題組與南方科技大學教授王鵬合作完成了題為Machine Driven Chemoenzymatic Synthesis of Glycopeptide的通訊論文在線發(fā)表在Angew. Chem. Int. Ed.上。該研究報道了利用商業(yè)化多肽合成儀和化學酶法合成策略合成帶有復(fù)雜寡糖結(jié)構(gòu)的糖肽（Proof of Concept）。
Recently, the Research Group of Literary Youth Retention of Shanghai Institute of Materia Medica, Chinese Academy of Sciences, cooperated with Professor Wang Peng of South University of Science and Technology to complete a communication paper entitled Machine Driven Chemoenzymatic Synthesis of Glycopeptide, which was published online in Angelw On Chem. Int. Ed. This study reported the synthesis of glycopeptides with complex oligosaccharide structures (Proof of Concept) using a commercial peptide synthesizer and a chemical enzymatic synthesis strategy.
在該研究中，研究人員通過篩選大量可用于固相合成的固相載體，發(fā)現(xiàn)了一種表面被氨基化的硅球，它可以同時被用作有機相的肽鏈合成與水相寡糖合成（酶反應(yīng)）。這種硅球僅表面具有氨基基團，因此研究人員設(shè)計了可斷裂的linker將硅球樹脂與起始氨基酸相連接。雖然這種硅球樹脂裝載效率比常用的多肽合成的固相樹脂低，但可以同時支持有機相中進行的多肽合成反應(yīng)與水相中進行的酶催化反應(yīng)?；诖?，研究人員結(jié)合商業(yè)化多肽合成儀開發(fā)出了包含兩相反應(yīng)的體系，用于糖肽合成的技術(shù)平臺。將裝載有初始氨基酸的樹脂預(yù)先加入到反應(yīng)釜中，然后合成儀自動將下一個氨基酸與縮合試劑（脫保護試劑）加入反應(yīng)釜中，反應(yīng)完成后加壓過濾其余試劑，即完成一個循環(huán)。通過設(shè)置反應(yīng)程序，可以使對應(yīng)的氨基酸依次進行循環(huán)反應(yīng)，在多個循環(huán)后就可得到目標肽鏈。之后系統(tǒng)切換為水相，將不同的糖基轉(zhuǎn)移酶與對應(yīng)的糖核苷依次進行同樣的循環(huán)反應(yīng)（反應(yīng)溫度為37℃），經(jīng)過多個循環(huán)后就可以得到目標糖肽，然后將糖肽從樹脂上洗脫。該糖肽合成平臺簡單易操作，基于商業(yè)化的多肽合成儀實現(xiàn)了13種復(fù)雜糖肽（10種腫瘤標志物MUC1糖肽與三種HIV糖肽）的半自動合成。
In this study, researchers screened a large number of solid-phase carriers that can be used for solid-phase synthesis and discovered a surface aminated silica sphere that can be used simultaneously for peptide chain synthesis in organic phases and oligosaccharide synthesis in aqueous phases (enzyme reaction). This type of silicon sphere only has amino groups on its surface, so researchers designed a breakable linker to connect the silicon sphere resin with the starting amino acid. Although the loading efficiency of this silicone resin is lower than that of commonly used solid-phase resins for peptide synthesis, it can simultaneously support peptide synthesis reactions in organic phases and enzyme catalyzed reactions in aqueous phases. Based on this, researchers have developed a technology platform for glycopeptide synthesis by combining a commercial peptide synthesizer with a two-phase reaction system. Pre add the resin loaded with initial amino acids into the reaction vessel, and then the synthesizer automatically adds the next amino acid and condensation reagent (deprotection reagent) into the reaction vessel. After the reaction is complete, filter the remaining reagents under pressure to complete one cycle. By setting up a reaction program, the corresponding amino acids can undergo cyclic reactions in sequence, and the target peptide chain can be obtained after multiple cycles. Afterwards, the system switches to aqueous phase, and different glycosyltransferases are sequentially subjected to the same cyclic reaction with their corresponding nucleosides (reaction temperature is 37 ℃). After multiple cycles, the target glycopeptide can be obtained, and then the glycopeptide is eluted from the resin. The glycopeptide synthesis platform is simple and easy to operate, and based on a commercial peptide synthesizer, it has achieved semi-automatic synthesis of 13 complex glycopeptides (10 tumor marker MUC1 glycopeptides and three HIV glycopeptides).
研究獲得美國NIH Common Fund Glycoscience program和上海藥物所人才啟動經(jīng)費支持。
The research received funding support from the NIH Common Fund Glycoscience program in the United States and the Shanghai Institute of Materia Medica Talent Launch Fund.
文留青課題組長期從事寡糖以及糖綴合物的合成，以及利用化學生物學手段對細胞表面寡糖的進行標記，研究寡糖與疾病的關(guān)系，并在此基礎(chǔ)上從事寡糖新藥研究和藥物靶點發(fā)現(xiàn)。
The Wen Liuqing research group has long been engaged in the synthesis of oligosaccharides and sugar conjugates, as well as the labeling of cell surface oligosaccharides using chemical biology methods, studying the relationship between oligosaccharides and diseases, and based on this, conducting research on new oligosaccharides drugs and drug target discovery.