Protein in blood plasma which can destroy Gram-negative bacteria and neutralise viruses when acting together with magnesium.
Non-specific antibody component of blood serum, active against many bacteria, viruses and yeasts. Properdin is thermolabile, and contained in euglobulin.
A group of substances in blood plasma that, in combination with complement and magnesium ions, is capable of destroying certain bacteria and viruses. The properdin complex occurs naturally, rather than as the result of previous exposure to microorganisms, and its activity is not directed against any particular species.
A plasma protein that stabilizes the enzyme C3 convertase, and helps to activate the alternative pathway of the complement cascade.