Arginine 719 in human plasminogen mediates formation of the staphylokinase:plasmin activator complex

The role of arginine 719 found in human plasminogen in the formation of the staphylokinase:plasmin activator complex was investigated. Alanine-mutagenesis was applied to phage-displayed micro-plasminogen to determine the plasmin residues required for generating the staphylokinase: plasmin activator interface. Results showed that replacement of arginine 719 with Ala dramatically reduces the binding affinity and plasminogen activation potential of the staphylokinase:micro-plasminogen complex.