Fig. 4

ZmpC in CZ130302 cleaves human MMP-9. (A) The three-dimensional structures of ZmpC in S. pneumoniae TIGR4 (left) and S. suis CZ130302 (right) were predicted using the online site SWISS-MODEL. Conserved HEXXH…E motifs in α-helix are shown in red boxes. (B) Schematic representation of the structure of ZmpC in S. suis CZ130302. ZmpC in CZ130302 contains complete M26 N-terminal and C-terminal domains. (C) The purified recombinant protein ZmpC-M26 was incubated with human MMP-9 for gelatin zymography analysis. The first lane indicates that the sample has only 2 µg human MMP-9, the second to sixth lanes indicate that 2 µg human MMP-9 was incubated with different concentrations of ZmpC-M26 (900 ng to 1300 ng), and the eighth lane indicates that the sample has only ZmpC-M26. The red arrow indicates the detection of a bright band of approximately 52 kDa. The results showed that ZmpC cleaves human MMP-9. (D) The purified recombinant protein ZmpE-M26 (900 ng to 1300 ng) was incubated with human MMP-9 for gelatin zymography analysis. No other bright bands were detected in the incubation group, indicating that ZmpE cannot cleave human MMP-9. The original gel is presented in Supplementary material 4