Ribophorin I usually interacts with those proteins that have a wrong folding; otherwise, this protein does not interact with native state proteins. This suggests that ribophorin I may work as a chaperone that recognizes the proteins with a wrong folding. Moreover, this ribophorin can regulate the delivery of precursor proteins to the oligosaccharyltransferase (main enzyme of the N-glycosylation for proteins), through the capture of substrates and taking them to the catalytic center. So that, ribophorin I can keep those possible substrates in the proximity of the catalytic subunit of the enzyme; this way, the efficiency of the N-glycosylation reaction will improve during their biogenesis in the ER. But ribophorin I only changes drastically the N-glycosylation of determined substrates, as it is apparently dispensable in the same process with other substrates. When ribophorin is not essential, these precursors have shortcut to the catalytic center of the oligosaccharyltransferase or their presence depends on the rest of the non-catalytic subunits in the complex. It shows the specificity of ribophorin I for determined substrates; so that, this protein will regulate selectively the delivery of substrates to the catalytic center of the oligosaccharyltransferase complex.