bioRxiv preprint doi: https://doi.org/10.1101/2020.05.06.081885; this version posted May 7, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. In situ detection of protein interactions for recombinant therapeutic enzymes Mojtaba Samoudi*,1,2, Chih-Chung Kuo*,2,3, Caressa M. Robinson*,2,3, Km Shams-Ud- Doha4, Song-Min Schinn1,2, Stefan Kol5, Linus Weiss6, Sara Petersen Bjorn5, Bjorn G. Voldborg5, Alexandre Rosa Campos4, Nathan E. Lewis1,2,3, 1 Dept of Pediatrics, University of California, San Diego 2 Novo Nordisk Foundation Center for Biosustainability at UC San Diego 3 Dept of Bioengineering, University of California, San Diego 4 Sanford Burnham Prebys Medical Discovery Institute 5 Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark 6 Dept of Biochemistry, Eberhard Karls University of Tübingen, Germany * Equal contribution Correspondence to Nathan E. Lewis,
[email protected] Abstract Despite their therapeutic potential, many protein drugs remain inaccessible to patients since they are difficult to secrete. Each recombinant protein has unique physicochemical properties and requires different machinery for proper folding, assembly, and post-translational modifications (PTMs). Here we aimed to identify the machinery supporting recombinant protein secretion by measuring the protein-protein interaction (PPI) networks of four different recombinant proteins (SERPINA1, SERPINC1, SERPING1 and SeAP) with various PTMs and structural motifs using the proximity- dependent biotin identification (BioID) method. We identified PPIs associated with specific features of the secreted proteins using a Bayesian statistical model, and found proteins involved in protein folding, disulfide bond formation and N-glycosylation were positively correlated with the corresponding features of the four model proteins.