Of note, in contrast to classical approaches, which involve the use of an insoluble fusion partner, for example, an α-galactosidase fragment in the case of insulin [43], to provoke formation of inclusion bodies and protect the gene product from intracellular proteolysis, the PASylated Tα1 peptide was recovered as a soluble fusion protein, thus allowing direct purification from the cell extract without solubilization steps. Furthermore, the C-terminally attached PAS moiety was compatible with N-terminal acetylation by RimJ as confirmed by ESI-MS. Yields of our expression study at the research scale reached 15 mg purified acetylated Tα1-PAS and even 50 mg PAS-Tα1 per 1 L bacterial culture (at an optical density (OD) of 3), which surpasses the reported yield of a bacterially produced (yet probably non-acetylated and non-glycosylated) Tα1-Fc fusion protein (16 mg/L) [44].