Site-specific modification of proteins with microbial transglutaminase (MTG) is a powerful and versatile strategy for a controlled modification of proteins under physiological conditions. We present evidence that solid-phase microbead-immobilization can be used to site-specifically and efficiently attach different functional molecules important for further downstream applications to proteins of therapeutic relevance including scFV, Fab-fragment and antibodies. We demonstrate that MTG remained firmly immobilized with no detectable column bleeding and that enzyme activity was sustained during continuous operation, which allowed for a convenient recycling of the enzyme, thus going beyond solution-phase MTG conjugation. In addition it is showed that immobilized MTG shows enhanced selectivity towards a certain residue in the presence of several reactive residues which are all targeted if the conjugation was carried out in solution.
用微
生物转谷
氨酰胺酶(
MTG)对蛋白质进行位点特异性修饰是在生理条件下对蛋白质进行可控修饰的一种强大而多用途的策略。我们提出的证据表明,固相微珠固定化技术可用于定点、高效地将对进一步下游应用非常重要的不同功能分子附着到具有治疗意义的蛋白质上,包括 scFV、Fab 片段和
抗体。我们的研究表明,
MTG 被牢牢固定,没有检测到色谱柱渗漏,而且在连续操作过程中酶的活性得以保持,从而方便了酶的再循环,超越了溶液相
MTG 连接。此外,研究还表明,如果在溶液中进行缀合,固定化的
MTG 会在存在多个反应残基的情况下对某个残基显示出更强的选择性,而这些反应残基都是缀合的目标。