On the Relationship between the Indicator Profile and Prosthetic Group of Mucoproteins Inhibitory for Influenza Virus Haemagglutinin

SUMMARY: The inhibitory titres of ovine and bovine submaxillary gland mucoproteins (OSM and BSM respectively), urinary mucoprotein, ovomucin and of the heat-stable seromucoid fraction of six animal species were determined under standard conditions against the same set of ten indicators derived from influenza viruses. By expressing relative rather than absolute titres ‘indicator profiles’ were obtained permitting direct comparison. OSM and BSM gave the most characteristic individual profiles and they closely resembled each other. Since the basic structures of the prosthetic groups of OSM and BSM are known to be identical, the close similarity of the profiles is regarded as resulting from this identity. A similar relationship seems to hold for the heat-stable mucoprotein fraction of various animal sera which have nearly identical profiles though distinctly different from the profile of the submaxillary mucoproteins.