Glycopeptide analogues of PSGL-1 inhibit P-selectin in vitro and in vivo

Abstract

Blockade of P-selectin/PSGL-1 interactions holds significant potential for treatment of disorders of innate immunity, thrombosis, and cancer. Current inhibitors remain limited due to low binding affinity or by the recognized disadvantages inherent to chronic administration of antibody therapeutics. Here we report an efficient approach for generating glycosulfopeptide mimics of N-terminal PSGL-1 through development of a stereoselective route for multi-gram scale synthesis of the C2 O-glycan building block and replacement of hydrolytically labile tyrosine sulfates with isosteric sulfonate analogs. Library screening afforded a compound of exceptional stability, GSnP-6, that binds to human P-selectin with nanomolar affinity (Kd ~ 22 nM). Molecular dynamics simulation defines the origin of this affinity in terms of a number of critical structural contributions. GSnP-6 potently blocks P-selectin/PSGL-1 interactions in vitro and in vivo and represents a promising candidate for the treatment of diseases driven by acute and chronic inflammation.

Targeting P-selectin glycoprotein ligand-1/P-selectin interactions as a novel therapy for metabolic syndrome

“…Specifically, molecular dynamic simulations have been used to account for structural elements of PSGL-1/P-selectin interactions as determined by both crystallographic and experimental data, and guide the design of glycomimetics [144]. With added insight, a stereoselective scheme has been developed in order to achieve a multi-gram, preparative scale (>50g) synthesis of the C2 O-glycan [144].…”

“…Specifically, molecular dynamic simulations have been used to account for structural elements of PSGL-1/P-selectin interactions as determined by both crystallographic and experimental data, and guide the design of glycomimetics [144]. With added insight, a stereoselective scheme has been developed in order to achieve a multi-gram, preparative scale (>50g) synthesis of the C2 O-glycan [144]. Furthermore, in order to address the acid lability of tyrosine sulfate, discovery that these groups can be replaced with hydrolytically stable isoteric sulphonates (Fmoc-Phe ( p -CH 2 SO 3 H) [145, 146] and Fmoc-Phe ( p -SO 3 H)[147]) has led to an overall increase in GSP yield from < 0.5% when tyrosine O-sulfates were used to 24% when the corresponding sulfonate analogues were synthesized [144].…”

“…Through use of these approaches, a novel PSGL-1 glycomimetic model compound, GSnP-6, has been identified as a low nanomolar antagonist of PSGL-1/P-selectin interactions both in vitro and in vivo [144, 148]. GSnP-6 was the result of a screening program intended to inform the rational design of PSGL-1 mimetics in which critical, high-affinity, carbohydrate and peptide recognition epitopes were preserved [144].…”

“…GSnP-6 was the result of a screening program intended to inform the rational design of PSGL-1 mimetics in which critical, high-affinity, carbohydrate and peptide recognition epitopes were preserved [144]. Currently, GSnP-6 has the highest known binding affinity to human P-selectin with a K d of 22 nM, comparable to that of native PSGL-1, which has a K d of approximately 70 nM [149].…”

The physiology of blood platelets and changes of their biological activities in multiple sclerosis

“…Interaction of platelets with monocytes induces EMMPRIN-dependent monocyte production of NF-κB-mediated MMP-9 and inflammatory cytokines such as IL-6 and TNFα . The direct interaction of neutrophils and platelets seems to be mediated by neutrophilic PSGL-1 and P-selectin on activated platelets (Krishnamurthy et al 2015).…”