Quercetin-3-rutinoside Inhibits Protein Disulfide Isomerase by Binding to Its b'x Domain.

Abstract

Quercetin-3-rutinoside inhibits thrombus formation in a mouse model by inhibiting extracellular protein disulfide isomerase (PDI), an enzyme required for platelet thrombus formation and fibrin generation. Prior studies have identified PDI as a potential target for novel antithrombotic agents. Using a fluorescence enhancement-based assay and isothermal calorimetry, we show that quercetin-3-rutinoside directly binds to the b' domain of PDI with a 1:1 stoichiometry. The binding of quercetin-3-rutinoside to PDI induces a more compact conformation and restricts the conformational flexibility of PDI, as revealed by small angle x-ray scattering. The binding sites of quercetin-3-rutinoside to PDI were determined by studying its interaction with isolated fragments of PDI. Quercetin-3-rutinoside binds to the b'x domain of PDI. The infusion of the b'x fragment of PDI rescued thrombus formation that was inhibited by quercetin-3-rutinoside in a mouse thrombosis model. This b'x fragment does not possess reductase activity and, in the absence of quercetin-3-rutinoside, does not affect thrombus formation in vivo. The isolated b' domain of PDI has potential as an antidote to reverse the antithrombotic effect of quercetin-3-rutinoside by binding and neutralizing quercetin-3-rutinoside.

• Authors: Lin Lin, Srila Gopal, Anish Sharda, Freda Passam, Sheryl R Bowley, Jack Stopa, Guangpu Xue, Cai Yuan, Barbara C Furie, Robert Flaumenhaft, Mingdong Huang, Bruce Furie
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 290 Issue 39 Pg. 23543-52 (Sep 25 2015) ISSN: 1083-351X [Electronic] United States
• PMID: 26240139 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Chemical References

• Rutin
• Protein Disulfide-Isomerases

Topics

• Animals
• Binding Sites
• Calorimetry
• Humans
• Inhibitory Concentration 50
• Mice
• Mice, Inbred C57BL
• Protein Disulfide-Isomerases (antagonists & inhibitors, metabolism)
• Rutin (metabolism, pharmacology)
• Scattering, Small Angle
• Thrombosis (prevention & control)
• X-Ray Diffraction