Solid-Phase Fragment Coupling Synthesis of Granulocyte Colony-Stimulating Factor

描述（由申请方提供）：粒细胞集落刺激因子（G-CSF）是一种重要的造血生长因子，属于较大类别的生物学相关糖蛋白细胞因子。G-CSF的两种治疗形式在临床上用于治疗化疗诱导的中性粒细胞减少症。这些形式之间的主要区别是在苏氨酸-133处存在或不存在O-连接的碳水化合物。通过化学合成制备两种治疗形式的既定平台可以解决关于G-CSF糖基化的重要性的问题。此外，该研究策略的进一步发展将允许模块化访问更有效的G-CSF变体。由于这些原因，糖蛋白G-CSF被认为是化学合成的靶标。 开发制备这种治疗性糖蛋白的有效合成方法是我们实验室的一个持续目标。这一建议需要调查的反应范围和限制方面，我们最近描述的固相片段耦合（SPFC）方法。该方法可用于固相上多肽C-端硫代酸与N-端多肽偶联聚合制备大分子多肽和糖肽。SPFC技术的应用将加快目的糖蛋白G-CSF的合成。为了推进该方法，将解决以下合成挑战：（1）C-末端硫代酸（+15聚体）的有效制备和（2）C-末端硫代酸与树脂结合的N-末端多肽的异腈介导的片段偶联以获得大多肽（+30聚体）。在这一进展之后，将在与G-CSF合成相关的靶多肽片段的背景下检查SPFC技术的实用性。这些靶向多肽将通过化学连接技术组装以制备G-CSF的均质糖基化和非糖基化形式。

DESCRIPTION (provided by applicant): Granulocyte colony-stimulating factor (G-CSF) is an important hematopoietic growth factor belonging to a larger class of biologically relevant glycoprotein cytokines. Two therapeutic forms of G-CSF are used clinically for the treatment of neutropenia induced by chemotherapy. The principal difference between these forms is the presence or absence of an O-linked carbohydrate at threonine-133. An established platform to prepare both therapeutic forms by means of chemical synthesis could address concerns with regard to the importance of G-CSF glycosylation. Additionally, further development of this research strategy would allow for modular access to more efficacious variants of G-CSF. For these reasons, glycoprotein G-CSF is considered a target for chemical synthesis. The development of efficient synthetic methods for the preparation of such therapeutic glycoproteins is an ongoing goal in our laboratory. This proposal entails the investigation of reaction scope and limitations with regard to our recently described solid-phase fragment coupling (SPFC) method. This method will be useful for the convergent preparation of large polypeptides and glycopeptides by the coupling of C-terminal polypeptide thioacids and N-terminal polypeptides on solid-phase. The application of SPFC technology would expedite the synthesis of target glycoprotein, G-CSF. To advance this method, the following synthetic challenges will be addressed: (1) the efficient preparation of C-terminal thioacids (+15-mers) and (2) the isonitrile mediated fragment coupling of C-terminal thioacids with resin-bound N-terminal polypeptides to access large polypeptides (+30-mers). Following this advance, the utility of SPFC technology will be examined in the context of target polypeptide fragments relevant to G-CSF synthesis. These targeted polypeptides will be assembled by chemical ligation techniques to prepare homogenously glycosylated and non-glycosylated forms of G-CSF.