Albumin Variant expression in yeast and its application to therapeutics

Abstract

Therapeutic proteins are used to treat a variety of diseases due to their low side effects and low immunogenicity. However, many therapeutic protein candidates suffer from short half-lives, due to degradation by proteases and removal by kidney filtration. To address this issue, various studies have been conducted to increase the half-life by conjugating human serum albumin (HSA). Previous studies have successfully conjugated therapeutic proteins to albumin using the SpyTag/SpyCatcher (ST/SC) system, leading to the development of Albucatcher, a novel conjugation platform that increases the half-life while maintaining activity. However, despite its many advantages, the resulting Albucatcher Ver.1 required multiple steps to fabricate, which left challenges to overcome, including time, effort, and reduced yield. Albucatcher Ver.2 aims to effectively reduce the multiple steps required to conjugate albumin with SpyCatcher (SC) by creating an albumin genetically conjugated with SpyCatcher and introducing it into yeast. We have confirmed that Albucatcher Ver.2 successfully forms a Uox-albumin conjugate (Uox-HSA) with Urate Oxidase (Uox), the model protein used for previous conjugation, and maintains the same activity.