Staphylokinase (SAK) forms a 1:1 stoichiometric complex with human plasmin (Pm) and switches its substrate specificity to generate a plasminogen (Pg) activator complex. Site-directed mutagenesis of SAKHis43 and SAKTyr44 demonstrated the crucial requirement of a positively charged and an aromatic residue, respectively, at these positions for optimal functioning of SAK-Pm activator complex. Molecular modeling studies further revealed the role of these residues in making cation-pi and pi-pi interactions with Trp215 of Pm and thus establishing the crucial intermolecular contacts within the active site cleft of the activator complex for the cofactor activity of SAK. © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Dahiya, M., Singh, S., Rajamohan, G., Sethi, D., Ashish, & Dikshit, K. L. (2011). Intermolecular interactions in staphylokinase-plasmin(ogen) bimolecular complex: Function of His43 and Tyr44. FEBS Letters, 585(12), 1814–1820. https://doi.org/10.1016/j.febslet.2011.04.030