The Complex Fibrinogen Interactions of the Staphylococcus aureus Coagulases

In this study, we have compared the secondary structure compositions and the Fg binding of the S. aureus coagulases Coa and vWbp. The similarity in circular dichroism (CD) spectra of the N-terminal halves of the two coagulases support earlier sequence analyses and molecular modeling studies (Friedrich et al., 2003; Kroh et al., 2009; Kroh and Bock, 2012; Ko et al., 2016; Liesenborghs et al., 2018). This suggests that it is likely that the D1D2 domain of vWbp-N, composed primarily of alpha helices, resembles the structure of the corresponding Coa segment (Friedrich et al., 2003), despite the fact that these segments only have 30% sequence identity (Bjerketorp et al., 2004). In addition, our CD data showed that substantial sections of the C-terminal regions of both vWbp and Coa have an intrinsically disordered character (Figures 2A,B, Supplementary Figure 3). vWbp and Coa fall into the zymogen activator and adhesion protein (ZAAP) family since they activate prothrombin non-proteolytically (Friedrich et al., 2003; McAdow et al., 2012b). Both coagulases can induce clotting of murine blood (Bjerketorp et al., 2004; Cheng et al., 2010) and the observed effects of vWbp and Coa in mouse infection models therefore seems clinically relevant. At the nidus of a murine abscess model, S. aureus is surrounded by a pseudocapsule (Cheng et al., 2009; McAdow et al., 2011), a layer of Fg that also contains Coa and prothrombin as revealed by antibody staining (Cheng et al., 2010). The periphery...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research