4AQH

Plasminogen activator inhibitor type-1 in complex with the inhibitor AZ3976

Summary for 4AQH

• Entry DOI: 10.2210/pdb4aqh/pdb
• Related: 1A7C 1B3K 1C5G 1DB2 1DVM 1DVN 1LJ5 1OC0 9PAI
• Descriptor: PLASMINOGEN ACTIVATOR INHIBITOR 1, TERT-BUTYL 3-[(4-OXO-3H-PYRIDO[2,3-D]PYRIMIDIN-2-YL)AMINO]AZETIDINE-1-CARBOXYLATE (3 entities in total)
• Functional Keywords: hydolase inhibitor, latent form
• Biological source: HOMO SAPIENS (HUMAN)
• Total number of polymer chains: 3
• Total formula weight: 130649.66

Authors

Fjellstrom, O.,Deinum, J.,Sjogren, T.,Johansson, C.,Geschwindner, S.,Nerme, V.,Legnehed, A.,McPheat, J.,Olsson, K.,Bodin, C.,Gustafsson, D. (deposition date: 2012-04-17, release date: 2012-11-28, Last modification date: 2023-12-20)

Primary citation

Fjellstrom, O.,Deinum, J.,Sjogren, T.,Johansson, C.,Geschwindner, S.,Nerme, V.,Legnehed, A.,Mcpheat, J.,Olsson, K.,Bodin, C.,Panuovic, A.,Gustafsson, D.
Characterization of a Small Molecule Inhibitor of Plasminogen Activator Inhibitor Type 1 that Accelerates the Transition Into the Latent Conformation
J.Biol.Chem., 288:873-, 2013

PubMed Abstract: A novel class of small molecule inhibitors for plasminogen activator inhibitor type 1 (PAI-1), represented by AZ3976, was identified in a high throughput screening campaign. AZ3976 displayed an IC(50) value of 26 μm in an enzymatic chromogenic assay. In a plasma clot lysis assay, the compound was active with an IC(50) of 16 μm. Surprisingly, AZ3976 did not bind to active PAI-1 but bound to latent PAI-1 with a K(D) of 0.29 μm at 35 °C and a binding stoichiometry of 0.94, as measured by isothermal calorimetry. Reversible binding was confirmed by surface plasmon resonance direct binding experiments. The x-ray structure of AZ3976 in complex with latent PAI-1 was determined at 2.4 Å resolution. The inhibitor was bound in the flexible joint region with the entrance to the cavity located between α-helix D and β-strand 2A. A set of surface plasmon resonance experiments revealed that AZ3976 inhibited PAI-1 by enhancing the latency transition of active PAI-1. Because AZ3976 only had measurable affinity for latent PAI-1, we propose that its mechanism of inhibition is based on binding to a small fraction in equilibrium with active PAI-1, a latent-like prelatent form, from which latent PAI-1 is then generated more rapidly. This mode of action, with induced accelerated latency transition of active PAI-1 may, together with supporting x-ray data, provide improved opportunities for small molecule drug design in the hunt for therapeutically useful PAI-1 inhibitors.

PubMed: 23155046
DOI: 10.1074/JBC.M112.371732

Experimental method

X-RAY DIFFRACTION (2.4 Å)