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Receptor residence time trumps drug-likeness and oral bioavailability in determining efficacy of complement C5a antagonists.

Seow V, Lim J, Cotterell AJ, Yau MK, Xu W, Lohman RJ, Kok WM, Stoermer MJ, Sweet MJ, Reid RC, Suen JY, Fairlie DP - Sci Rep (2016)

Bottom Line: The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor.Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h.Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.

View Article: PubMed Central - PubMed

Affiliation: Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.

ABSTRACT
Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3 nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1 -3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.

No MeSH data available.


Related in: MedlinePlus

Different mechanisms of C5aR antagonism by 3D53, W54011 and JJ47 against human C5a on human monocyte-derived macrophages.Top row: Binding affinities of (A) 3D53, (B) W54011 and (C) JJ47 measured by displacement of [125I]-C5a (25 pM) from HMDM. Middle row: Concentration dependent responses to C5a following treatment with antagonist (D) 3D53, (E) W54011 and (F) JJ47 at various concentrations (0 nM, ●; 3 nM, ■; 10 nM, ▲; 30 nM, ◆; 100 nM,  300 nM, ▼; 1000 nM, ★) with C5a (300 nM) as 100% response on human macrophages in a calcium release assay. Bottom row: Schild plots for antagonists (G) 3D53, (H) W54011 and (I) JJ47 against rhC5a. Calculated pA2 values are 8.3 (3D53), 8.6 (W54011) and 8.3 (JJ47). Error bars are means ± SEM of three independent experiments (n = 3).
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f2: Different mechanisms of C5aR antagonism by 3D53, W54011 and JJ47 against human C5a on human monocyte-derived macrophages.Top row: Binding affinities of (A) 3D53, (B) W54011 and (C) JJ47 measured by displacement of [125I]-C5a (25 pM) from HMDM. Middle row: Concentration dependent responses to C5a following treatment with antagonist (D) 3D53, (E) W54011 and (F) JJ47 at various concentrations (0 nM, ●; 3 nM, ■; 10 nM, ▲; 30 nM, ◆; 100 nM, 300 nM, ▼; 1000 nM, ★) with C5a (300 nM) as 100% response on human macrophages in a calcium release assay. Bottom row: Schild plots for antagonists (G) 3D53, (H) W54011 and (I) JJ47 against rhC5a. Calculated pA2 values are 8.3 (3D53), 8.6 (W54011) and 8.3 (JJ47). Error bars are means ± SEM of three independent experiments (n = 3).

Mentions: Comparative antagonist potencies and mechanisms under identical conditions were investigated here for the three chemical probes (3D53, W54011, JJ47) in human monocyte-derived macrophages (HMDM). In competitive radioligand-binding experiments using recombinant human 125I-C5a, the binding affinities of 3D53 and W54011 for HMDM were comparable, and only slightly weaker for JJ47 (Fig. 2A–C). The concentration-response curves for calcium mobilization induced by rhC5a were determined in the presence of escalating concentrations of each of the three antagonists (Fig. 2D–F). A reduction of the maximal C5a responses was observed as the concentration of 3D53 increased, but there was no rightward shift of the curve typical of competitive or surmountable antagonism, consistent instead with insurmountable C5aR antagonism by 3D53 (Fig. 2D). By contrast, both W54011 and JJ47 were dependent on the C5a concentration. Both caused a rightward shift in concentration-response curves for C5a-induced calcium release in HMDM, without depressing the maximal responses, indicating that both compounds were surmountable antagonists (Fig. 2E,F). A Schild plot and pA2 analysis revealed a slope of 0.5 for 3D53 (Fig. 2G), indicating it as a non-competitive rather than competitive antagonist18. On the other hand, the slopes for W54011 (Fig. 2H) and JJ47 (Fig. 2I) were both ~1, consistent with these compounds being competitive antagonists with C5a on HMDM and antagonist IC50 values being dependent on the concentration of C5a used.


Receptor residence time trumps drug-likeness and oral bioavailability in determining efficacy of complement C5a antagonists.

Seow V, Lim J, Cotterell AJ, Yau MK, Xu W, Lohman RJ, Kok WM, Stoermer MJ, Sweet MJ, Reid RC, Suen JY, Fairlie DP - Sci Rep (2016)

Different mechanisms of C5aR antagonism by 3D53, W54011 and JJ47 against human C5a on human monocyte-derived macrophages.Top row: Binding affinities of (A) 3D53, (B) W54011 and (C) JJ47 measured by displacement of [125I]-C5a (25 pM) from HMDM. Middle row: Concentration dependent responses to C5a following treatment with antagonist (D) 3D53, (E) W54011 and (F) JJ47 at various concentrations (0 nM, ●; 3 nM, ■; 10 nM, ▲; 30 nM, ◆; 100 nM,  300 nM, ▼; 1000 nM, ★) with C5a (300 nM) as 100% response on human macrophages in a calcium release assay. Bottom row: Schild plots for antagonists (G) 3D53, (H) W54011 and (I) JJ47 against rhC5a. Calculated pA2 values are 8.3 (3D53), 8.6 (W54011) and 8.3 (JJ47). Error bars are means ± SEM of three independent experiments (n = 3).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4837355&req=5

f2: Different mechanisms of C5aR antagonism by 3D53, W54011 and JJ47 against human C5a on human monocyte-derived macrophages.Top row: Binding affinities of (A) 3D53, (B) W54011 and (C) JJ47 measured by displacement of [125I]-C5a (25 pM) from HMDM. Middle row: Concentration dependent responses to C5a following treatment with antagonist (D) 3D53, (E) W54011 and (F) JJ47 at various concentrations (0 nM, ●; 3 nM, ■; 10 nM, ▲; 30 nM, ◆; 100 nM, 300 nM, ▼; 1000 nM, ★) with C5a (300 nM) as 100% response on human macrophages in a calcium release assay. Bottom row: Schild plots for antagonists (G) 3D53, (H) W54011 and (I) JJ47 against rhC5a. Calculated pA2 values are 8.3 (3D53), 8.6 (W54011) and 8.3 (JJ47). Error bars are means ± SEM of three independent experiments (n = 3).
Mentions: Comparative antagonist potencies and mechanisms under identical conditions were investigated here for the three chemical probes (3D53, W54011, JJ47) in human monocyte-derived macrophages (HMDM). In competitive radioligand-binding experiments using recombinant human 125I-C5a, the binding affinities of 3D53 and W54011 for HMDM were comparable, and only slightly weaker for JJ47 (Fig. 2A–C). The concentration-response curves for calcium mobilization induced by rhC5a were determined in the presence of escalating concentrations of each of the three antagonists (Fig. 2D–F). A reduction of the maximal C5a responses was observed as the concentration of 3D53 increased, but there was no rightward shift of the curve typical of competitive or surmountable antagonism, consistent instead with insurmountable C5aR antagonism by 3D53 (Fig. 2D). By contrast, both W54011 and JJ47 were dependent on the C5a concentration. Both caused a rightward shift in concentration-response curves for C5a-induced calcium release in HMDM, without depressing the maximal responses, indicating that both compounds were surmountable antagonists (Fig. 2E,F). A Schild plot and pA2 analysis revealed a slope of 0.5 for 3D53 (Fig. 2G), indicating it as a non-competitive rather than competitive antagonist18. On the other hand, the slopes for W54011 (Fig. 2H) and JJ47 (Fig. 2I) were both ~1, consistent with these compounds being competitive antagonists with C5a on HMDM and antagonist IC50 values being dependent on the concentration of C5a used.

Bottom Line: The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor.Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h.Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.

View Article: PubMed Central - PubMed

Affiliation: Division of Chemistry and Structural Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.

ABSTRACT
Drug discovery and translation are normally based on optimizing efficacy by increasing receptor affinity, functional potency, drug-likeness (rule-of-five compliance) and oral bioavailability. Here we demonstrate that residence time of a compound on its receptor has an overriding influence on efficacy, exemplified for antagonists of inflammatory protein complement C5a that activates immune cells and promotes disease. Three equipotent antagonists (3D53, W54011, JJ47) of inflammatory responses to C5a (3 nM) were compared for drug-likeness, receptor affinity and antagonist potency in human macrophages, and anti-inflammatory efficacy in rats. Only the least drug-like antagonist (3D53) maintained potency in cells against higher C5a concentrations and had a much longer duration of action (t1/2 ~ 20 h) than W54011 or JJ47 (t1/2 ~ 1 -3 h) in inhibiting macrophage responses. The unusually long residence time of 3D53 on its receptor was mechanistically probed by molecular dynamics simulations, which revealed long-lasting interactions that trap the antagonist within the receptor. Despite negligible oral bioavailability, 3D53 was much more orally efficacious than W54011 or JJ47 in preventing repeated agonist insults to induce rat paw oedema over 24 h. Thus, residence time on a receptor can trump drug-likeness in determining efficacy, even oral efficacy, of pharmacological agents.

No MeSH data available.


Related in: MedlinePlus