Proteinaceous rhymes with:
ignatius, tenacious, audacious, capacious, ceraceous, crustaceous, efficacious, fallacious, flirtatious, gracious, hellacious, herbaceous, horatius, ignatius, loquacious, mendacious, ostentatious, perspicacious, predaceous, salacious, sebaceous, spacious, tenacious, vexatious, vivacious, voracious
Proteinaceous sounds like:
parading, paradyne's, pardoning, pardons, parting, partitioning, partitions, partying, pertaining, pertains, pirating, porting, portions, predominance, preteens, pretense, pretenses, prodding, protein's, proteins, proton's, protons, prudence, prudency, puritans