Enzymes 。Coagulase Coagulate blood 。Kinases Digest fibrin clots 。Hyaluronidase Hydrolyses hyaluronic acid 。Collagenase Hydrolyzes collagen ·IgA proteases Destroy IgA antibodies ·Siderophores Take iron from host iron- binding proteins 。Antigenic variation Alter surface proteins • Coagulase Coagulate blood • Kinases Digest fibrin clots • Hyaluronidase Hydrolyses hyaluronic acid • Collagenase Hydrolyzes collagen • IgA proteases Destroy IgA antibodies • Siderophores Take iron from host iron￾binding proteins • Antigenic variation Alter surface proteins Enzymes