Bioorganic Chemistry, University of Bayreuth, Universitätsstraße 30, 95447, Bayreuth, Germany.
Department of Pathology, Medical Faculty, Otto von Guericke University Magdeburg, 39120, Magdeburg, Germany.
Angew Chem Int Ed Engl. 2021 Jun 7;60(24):13380-13387. doi: 10.1002/anie.202101496. Epub 2021 May 6.
A library of glycoforms of human interleukin 6 (IL-6) comprising complex and mannosidic N-glycans was generated by semisynthesis. The three segments were connected by sequential native chemical ligation followed by two-step refolding. The central glycopeptide segments were assembled by pseudoproline-assisted Lansbury aspartylation and subsequent enzymatic elongation of complex N-glycans. Nine IL-6 glycoforms were synthesized, seven of which were evaluated for in vivo plasma clearance in rats and compared to non-glycosylated recombinant IL-6 from E. coli. Each IL-6 glycoform was tested in three animals and reproducibly showed individual serum clearances depending on the structure of the N-glycan. The clearance rates were atypical, since the 2,6-sialylated glycoforms of IL-6 cleared faster than the corresponding asialo IL-6 with terminal galactoses. Compared to non-glycosylated IL-6 the plasma clearance of IL-6 glycoforms was delayed in the presence of larger and multibranched N-glycans in most cases.
通过半合成方法生成了人白细胞介素 6（IL-6）的聚糖文库，其中包含复杂和甘露糖基 N-聚糖。通过顺序的天然化学连接和两步复性连接三个片段。通过拟脯氨酸辅助 Lansbury 天冬氨酸化和随后的复杂 N-聚糖的酶延伸来组装中间糖肽片段。合成了 9 种 IL-6 糖型，其中 7 种在大鼠体内进行了血浆清除率评估，并与来自大肠杆菌的非糖基化重组 IL-6 进行了比较。每种 IL-6 糖型在 3 只动物中进行了测试，根据 N-聚糖的结构重现了个体血清清除率。清除率是非典型的，因为 2,6-唾液酸化的 IL-6 糖型比具有末端半乳糖的相应去唾液酸 IL-6 清除得更快。与非糖基化的 IL-6 相比，在大多数情况下，具有更大和多分支 N-聚糖的 IL-6 糖型的血浆清除率会延迟。
