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Complement Evasion Mediated by Enhancement of Captured Factor H: Implications for Protection of Self-Surfaces from Complement.

Herbert AP, Makou E, Chen ZA, Kerr H, Richards A, Rappsilber J, Barlow PN - J. Immunol. (2015)

Bottom Line: We found, using site-directed and truncation mutagenesis, surface plasmon resonance, nuclear magnetic resonance spectroscopy, and cross-linking and mass spectrometry, that the N-terminal domain of Streptococcus pneumoniae protein PspC (PspCN) not only binds FH extraordinarily tightly but also holds it in a previously uncharacterized conformation.This conformational change of FH doubles its affinity for C3b and increases 5-fold its ability to accelerate decay of the binary enzyme (C3bBb) responsible for converting C3 to C3b in an amplification loop.We propose that these bacterial proteins mimic molecular markers of self-surfaces, providing a compelling hypothesis for how FH prevents complement-mediated injury to host tissue while lacking efficacy on virtually all other surfaces.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom;

No MeSH data available.


Related in: MedlinePlus

NMR-based study of FH 8-9:PspCN complex. 1H,15H(NMR) spectra for (A) free D39 15N-PspCN, (B) D39 15N-PspCN bound to FH 8–9, (C) free 15N-FH 8–9, (D) 15N-FH 8–9 bound to (D39)PspCN. Differences between (A) and (B) suggest D39(PspCN) adopts a more compactly folded structure upon binding FH 8–9. Many chemical shift differences between (C) and (D) suggest extensive contacts between FH 8–9 and (D39)PspCN. For higher resolution and overlaid spectra (see Supplemental Fig. 2).
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fig04: NMR-based study of FH 8-9:PspCN complex. 1H,15H(NMR) spectra for (A) free D39 15N-PspCN, (B) D39 15N-PspCN bound to FH 8–9, (C) free 15N-FH 8–9, (D) 15N-FH 8–9 bound to (D39)PspCN. Differences between (A) and (B) suggest D39(PspCN) adopts a more compactly folded structure upon binding FH 8–9. Many chemical shift differences between (C) and (D) suggest extensive contacts between FH 8–9 and (D39)PspCN. For higher resolution and overlaid spectra (see Supplemental Fig. 2).

Mentions: To further address the participation of CCPs 8 and 9 of FH in PspCN binding, 1H,15N heteronuclear single-quantum coherence nuclear magnetic resonance (NMR) spectra of 15N-PspCN were recorded with and without FH 8–9 (Fig. 4A, 4B, Supplemental Fig. 2). The spectrum of (D39)PspCN suggests a molten globule as was supported by its binding of anilino-1-naphthalenesulfonic acid (data not shown). Following complex formation with FH 8–9, bound PspCN yielded a spectrum containing well dispersed and resolved cross peaks, reflecting transition to a folded conformation upon complex formation. In other experiments, spectra of 15N-FH 8–9 were recorded with or without unlabeled PspCN (Fig. 4C, 4D). Judging from the uniform appearance of the well-dispersed cross peaks, both modules appeared to be compactly folded with any mobility restricted to loops and turns. Fig. 4D reveals numerous chemical-shift perturbations, reflecting plentiful contacts with PspCN in CCPs 8 and 9, as may also be judged from the overlaid spectra in Supplemental Fig. 2.


Complement Evasion Mediated by Enhancement of Captured Factor H: Implications for Protection of Self-Surfaces from Complement.

Herbert AP, Makou E, Chen ZA, Kerr H, Richards A, Rappsilber J, Barlow PN - J. Immunol. (2015)

NMR-based study of FH 8-9:PspCN complex. 1H,15H(NMR) spectra for (A) free D39 15N-PspCN, (B) D39 15N-PspCN bound to FH 8–9, (C) free 15N-FH 8–9, (D) 15N-FH 8–9 bound to (D39)PspCN. Differences between (A) and (B) suggest D39(PspCN) adopts a more compactly folded structure upon binding FH 8–9. Many chemical shift differences between (C) and (D) suggest extensive contacts between FH 8–9 and (D39)PspCN. For higher resolution and overlaid spectra (see Supplemental Fig. 2).
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Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4635569&req=5

fig04: NMR-based study of FH 8-9:PspCN complex. 1H,15H(NMR) spectra for (A) free D39 15N-PspCN, (B) D39 15N-PspCN bound to FH 8–9, (C) free 15N-FH 8–9, (D) 15N-FH 8–9 bound to (D39)PspCN. Differences between (A) and (B) suggest D39(PspCN) adopts a more compactly folded structure upon binding FH 8–9. Many chemical shift differences between (C) and (D) suggest extensive contacts between FH 8–9 and (D39)PspCN. For higher resolution and overlaid spectra (see Supplemental Fig. 2).
Mentions: To further address the participation of CCPs 8 and 9 of FH in PspCN binding, 1H,15N heteronuclear single-quantum coherence nuclear magnetic resonance (NMR) spectra of 15N-PspCN were recorded with and without FH 8–9 (Fig. 4A, 4B, Supplemental Fig. 2). The spectrum of (D39)PspCN suggests a molten globule as was supported by its binding of anilino-1-naphthalenesulfonic acid (data not shown). Following complex formation with FH 8–9, bound PspCN yielded a spectrum containing well dispersed and resolved cross peaks, reflecting transition to a folded conformation upon complex formation. In other experiments, spectra of 15N-FH 8–9 were recorded with or without unlabeled PspCN (Fig. 4C, 4D). Judging from the uniform appearance of the well-dispersed cross peaks, both modules appeared to be compactly folded with any mobility restricted to loops and turns. Fig. 4D reveals numerous chemical-shift perturbations, reflecting plentiful contacts with PspCN in CCPs 8 and 9, as may also be judged from the overlaid spectra in Supplemental Fig. 2.

Bottom Line: We found, using site-directed and truncation mutagenesis, surface plasmon resonance, nuclear magnetic resonance spectroscopy, and cross-linking and mass spectrometry, that the N-terminal domain of Streptococcus pneumoniae protein PspC (PspCN) not only binds FH extraordinarily tightly but also holds it in a previously uncharacterized conformation.This conformational change of FH doubles its affinity for C3b and increases 5-fold its ability to accelerate decay of the binary enzyme (C3bBb) responsible for converting C3 to C3b in an amplification loop.We propose that these bacterial proteins mimic molecular markers of self-surfaces, providing a compelling hypothesis for how FH prevents complement-mediated injury to host tissue while lacking efficacy on virtually all other surfaces.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom;

No MeSH data available.


Related in: MedlinePlus