Inhibition of Proteases in Host Cell Proteome of Physcomitrella patens for Stability of Recombinant Biopharmaceuticals

Host cell proteins are inevitable contaminants of biopharmaceuticals. Here, we performed detailed analyses of the host cell proteome of moss (Physcomitrella patens) bioreactor supernatants using mass spectrometry and subsequent bioinformatics analysis. Distinguishing between the apparent secretome and intracellular contaminants, a complex extracellular proteolytic network including subtilisin-like proteases, metallo-proteases, and aspartic proteases was identified. Knockout of a subtilisin-like protease affected the overall extracellular proteolytic activity. Besides proteases, also secreted protease-inhibiting proteins such as serpins were identified. Further, we confirmed predicted cleavage sites of 40 endogenous signal peptides employing an N-terminomics approach. The present data provide novel aspects to optimize both product stability of recombinant biopharmaceuticals as well as their maturation along the secretory pathway.

Faculty Supervisor:

Carlos Filipe

Student:

Partner:

Albert-Ludwigs-Universität Freiburg

Discipline:

Life Sciences

Sector:

Education

University:

McMaster University

Program: