The virulence-enhancing factor of mucins. 5. The different components of the ‘third factor’ involved in virulence enhancement

has shown that the virulence-enhancing action of hog gastric mucin is due to a synergic action between two non-specific factors (a viscous medium and a particulate residue) and a more specific soluble 'third factor'. Partial purification of the latter (Smith, 1951) yielded a heterogeneous product which was predominantly peptide in nature, but which contained 5-10 0 % of carbohydrate residues.