Marine-Derived Sulfated Glycans Inhibit the Interaction of Heparin with Adhesion Proteins of Mycoplasma pneumoniae

Abstract

Mycoplasma pneumoniae, a notable pathogen behind respiratory infections, employs specialized proteins to adhere to the respiratory epithelium, an essential process for initiating infection. The role of glycosaminoglycans, especially heparan sulfate, is critical in facilitating pathogen-host interactions, presenting a strategic target for therapeutic intervention. In this study, we assembled a glycan library comprising heparin, its oligosaccharide derivatives, and a variety of marine-derived sulfated glycans to screen the potential inhibitors for the pathogen-host interactions. By using Surface Plasmon Resonance spectroscopy, we evaluated the library's efficacy in inhibiting the interaction between M. pneumoniae adhesion proteins and heparin. Our findings offer a promising avenue for developing novel therapeutic strategies against M. pneumoniae infections.

Keywords: HSPGs; Mycoplasma pneumoniae; heparin; marine sulfated glycans; surface plasmon resonance.

Figure 1

Chemical structures of heparin and the various marine sulfated glycans.

Figure 2

SPR sensorgrams of M. pneumoniae proteins binding with heparin. (A) SPR sensorgrams of protein P30 binding with heparin. Concentrations of P30 were 500, 250, 125, 62.5, and 31.3 nM (from top to bottom, respectively). (B) SPR sensorgrams of P1-C protein binding with heparin. Concentrations of P1-C were 100, 50, 25, 12.5, and 6.25 nM (from top to bottom, respectively). The black curves are the fits using models from T200 Evaluate software (v3.2).

Figure 3

M. pneumoniae proteins–heparin interaction inhibited by heparin oligosaccharides and desulfated heparins using solution competition. (A) SPR sensorgrams of protein P30–heparin interaction competing with different heparin oligosaccharides. (B) Bar graphs of protein P30 binding preference to surface heparin by competing with different heparin oligosaccharides. (C) SPR sensorgrams of protein P1-C–heparin interaction competing with different heparin oligosaccharides. (D) Bar graphs of protein P1-C binding preference to surface heparin by competing with different heparin oligosaccharides. (E) SPR sensorgrams of protein P30–heparin interaction competing with different desulfated heparins. (F) Bar graphs of protein P30 binding preference to surface heparin by competing with different desulfated heparins. (G) SPR sensorgrams of protein P1-C–heparin interaction competing with different desulfated heparins. (H) Bar graphs of protein P1-C binding preference to surface heparin by competing with different desulfated heparins. Data are shown as mean ± SD and are analyzed using a one-way ANOVA/Tukey test. Significance is defined as p > 0.05 (ns), p < 0.05 (*), p < 0.01 (**), p < 0.001 (***), p < 0.0001 (****).

Figure 4

Solution competition between heparin and Ib glycans. (A) SPR sensorgrams of M. pneumoniae protein P30–heparin interaction competing with IbSF, IbFucCS, desIbSF, and desIbFucCS. (B) Bar of normalized protein P30 binding preference to surface heparin by competing with different Ib glycans. (C) SPR sensorgrams of M. pneumoniae protein P1-C–heparin interaction competing with IbSF, IbFucCS, desIbSF, and desIbFucCS. (D) Bar of normalized protein P1-C binding preference to surface heparin by competing with different Ib glycans. Data are shown as mean ± SD and are analyzed using a one-way ANOVA/Tukey test. Significance is defined as p > 0.05 (ns), p < 0.01 (**), p < 0.001 (***).

Figure 5

Solution competition between heparin and marine-soured sulfated glycans. (A) SPR sensorgrams of protein P30–heparin interaction competing with sulfated glycans derived from marine invertebrates. (B) Bar graphs of normalized protein P30 binding preference to surface heparin by competing with different sulfated glycans derived from marine invertebrates. (C) SPR sensorgrams of protein P1-C–heparin interaction competing with sulfated glycans derived from marine invertebrates. (D) Bar graphs of normalized protein P1-C binding preference to surface heparin by competing with different sulfated glycans derived from marine invertebrates. Data are shown as mean ± SD and are analyzed using a one-way ANOVA/Tukey test. Significance is defined p < 0.01 (**), p < 0.001 (***).