1. Solution structural model of the complex of the binding regions of human plasminogen with its M-protein receptor from Streptococcus pyogenes.
- Author
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Yuan Y, Ayinuola YA, Singh D, Ayinuola O, Mayfield JA, Quek A, Whisstock JC, Law RHP, Lee SW, Ploplis VA, and Castellino FJ
- Subjects
- Bacterial Proteins chemistry, Humans, Magnetic Resonance Spectroscopy, Protein Binding, Protein Structure, Secondary, Bacterial Proteins metabolism, Streptococcus pyogenes metabolism
- Abstract
VEK50 is a truncated peptide from a Streptococcal pyogenes surface human plasminogen (hPg) binding M-protein (PAM). VEK50 contains the full A-domain of PAM, which is responsible for its low nanomolar binding to hPg. The interaction of VEK50 with kringle 2, the PAM-binding domain in hPg (K2
hPg ), has been studied by high-resolution NMR spectroscopy. The data show that each VEK50 monomer in solution contains two tight binding sites for K2hPg , one each in the a1- (RH1; R17 H18 ) and a2- (RH2; R30 H31 ) repeats within the A-domain of VEK50. Two mutant forms of VEK50, viz., VEK50[RH1/AA] (VEK50ΔRH1 ) and VEK50[RH2/AA] (VEK50ΔRH2 ), were designed by replacing each RH with AA, thus eliminating one of the K2hPg binding sites within VEK50, and allowing separate study of each binding site. Using13 C- and15 N-labeled peptides, NMR-derived solution structures of VEK50 in its complex with K2hPg were solved. We conclude that the A-domain of PAM can accommodate two molecules of K2hPg docked within a short distance of each other, and the strength of the binding is slightly different for each site. The solution structure of the VEK50/K2hPg , complex, which is a reductionist model of the PAM/hPg complex, provides insights for the binding mechanism of PAM to a host protein, a process that is critical to S. pyogenes virulence., (Copyright © 2019 Elsevier Inc. All rights reserved.)- Published
- 2019
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