Applied and Environmental Microbiology
The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. . This strategy allowed the isolation of a strain with a functional -1,2-mannosidase producing increased amounts of N-glycans of the Man 5 GlcNAc 2 type. This strain was further engineered by the introduction of a functional GlcNAc transferase I construct yielding GlcNAcMan 5 GlcNac 2 N-glycans. Additionally, we deleted algC genes coding for an enzyme involved in an early step of the fungal glycosylation pathway yielding Man 3 GlcNAc 2 N-glycans. This modification of fungal glycosylation is a step toward the ability to produce humanized complex N-glycans on therapeutic proteins in filamentous fungi.
Kainz, Elke; Gallmetzer, Andreas; Hatzl, Christian; Nett, Juergen H.; Li, Huijuan; Schinko, Thorsten; Pachlinger, Robert; Berger, Harald; Reyes-Dominguez, Yazmid; Bernreiter, Andreas; Gerngross, Tillmann; Wildt, Stefan; and Strauss, Joseph, "N-Glycan Modification in Aspergillus Species" (2007). Open Dartmouth: Faculty Open Access Articles. 487.