ABS 055: Mechanisms of Ebselen Binding to MIF-2

Sirena D'Orazio (1), Vinnie Widjaja (2), George P. Lisi (3)

Van Wickle (2025) Volume 1, ABS055

Introduction: Macrophage migration inhibitory factor (MIF) and D-dopachrome tautomerase (MIF-2) are paralogues that both activate the cluster of differentiation 74 (CD74) receptor. Activation of CD74 causes an inflammatory response in the body. Excess inflammation, caused by abnormally large amounts of MIF, can contribute to diseases such as asthma and rheumatoid arthritis. Previous studies on MIF have shown that allosteric changes allow communication between the N and C termini, which contribute to its enzymatic activity. Specifically, cysteine residues seem to play a key role in MIF’s ability to bind to the CD74 receptor. Ebselen is a small molecule that has been shown to bind to these cysteines and disrupt the MIF homo-trimer, causing MIF to separate into non-functional monomers that cannot activate CD74. The effects of Ebselen on MIF2 have not been fully studied yet. We will use in-vitro assays to quantify the disruption of the MIF2 homo-trimer in the presence of Ebselen, and in-vivo assays to understand how Ebselen affects MIF2’s ability to bind to CD74 receptors and cause an inflammatory response. We will also use site-directed mutagenesis and NMR to better understand the role of cysteine in the structure of MIF2 and its importance for allosteric communication and enzymatic activity. Preliminary results suggest that Ebselen does disrupt the MIF2 homotrimer, but more experimentation is needed to understand how structural changes cause this disruption, and how this disruption might affect CD74 binding and inflammatory response.

Methods: We will use in-vitro assays to quantify the disruption of the MIF2 homo-trimer in the presence of Ebselen, and in-vivo assays to understand how Ebselen affects MIF2’s ability to bind to CD74 receptors and cause an inflammatory response. We will also use site-directed mutagenesis and NMR to better understand the role of cysteine in the structure of MIF2 and its importance for allosteric communication and enzymatic activity.

Results: Preliminary results suggest that Ebselen does disrupt the MIF2 homotrimer, but more experimentation is needed to understand how structural changes cause this disruption, and how this disruption might affect CD74 binding and inflammatory response.