Human Protein S exists in two forms in human plasma, as the free protein and in complex with Human C4b-binding protein. Enzyme Research Laboratories offers the free Human Protein S from plasma which serves as a cofactor for the anticoagulant activity of Human Activated Protein C. Human Protein S is a single chain glycoprotein with a molecular weight of 69,000. Human Protein S purity is determined by SDS-PAGE.

The human protein Z is purified from plasma via a combination of precipitations and column chromatography. HPZ purity is determined by SDS-PAGE and shows no reduction upon incubation with 2-mercaptoethanol.

At 300 ug/ml, plasma fibronectin is second to fibrinogen in abundance. It is a glycoprotein, composed of two subunits of approximately 220 kD each and participates in several cell-substratum adhesive interactions. Fibronectin binds to collagen, fibrinogen, fibrin, heparin. Enzyme Research Laboratories offers fibronectin purified by gelatin affinity chromatography followed by heparin chromatography.