5HZQ

Crystal structure of cellular retinoic acid binding protein 2 (CRABP2)-aryl fluorosulfate covalent conjugate

Summary for 5HZQ

• Entry DOI: 10.2210/pdb5hzq/pdb
• Descriptor: Cellular retinoic acid-binding protein 2, 4'-[(3,6,9,12-tetraoxapentadec-14-yn-1-yl)oxy][1,1'-biphenyl]-4-yl sulfurofluoridate, GLYCEROL, ... (4 entities in total)
• Functional Keywords: lipid binding protein, aryl fluorosulfate, retinoic acid
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 32873.53

Authors

Chen, W.,Mortenson, D.E.,Wilson, I.A.,Kelly, J.W. (deposition date: 2016-02-02, release date: 2016-06-01, Last modification date: 2024-10-23)

Primary citation

Chen, W.,Dong, J.,Plate, L.,Mortenson, D.E.,Brighty, G.J.,Li, S.,Liu, Y.,Galmozzi, A.,Lee, P.S.,Hulce, J.J.,Cravatt, B.F.,Saez, E.,Powers, E.T.,Wilson, I.A.,Sharpless, K.B.,Kelly, J.W.
Arylfluorosulfates Inactivate Intracellular Lipid Binding Protein(s) through Chemoselective SuFEx Reaction with a Binding Site Tyr Residue.
J.Am.Chem.Soc., 138:7353-7364, 2016

PubMed Abstract: Arylfluorosulfates have appeared only rarely in the literature and have not been explored as probes for covalent conjugation to proteins, possibly because they were assumed to possess high reactivity, as with other sulfur(VI) halides. However, we find that arylfluorosulfates become reactive only under certain circumstances, e.g., when fluoride displacement by a nucleophile is facilitated. Herein, we explore the reactivity of structurally simple arylfluorosulfates toward the proteome of human cells. We demonstrate that the protein reactivity of arylfluorosulfates is lower than that of the corresponding aryl sulfonyl fluorides, which are better characterized with regard to proteome reactivity. We discovered that simple hydrophobic arylfluorosulfates selectively react with a few members of the intracellular lipid binding protein (iLBP) family. A central function of iLBPs is to deliver small-molecule ligands to nuclear hormone receptors. Arylfluorosulfate probe 1 reacts with a conserved tyrosine residue in the ligand-binding site of a subset of iLBPs. Arylfluorosulfate probes 3 and 4, featuring a biphenyl core, very selectively and efficiently modify cellular retinoic acid binding protein 2 (CRABP2), both in vitro and in living cells. The X-ray crystal structure of the CRABP2-4 conjugate, when considered together with binding site mutagenesis experiments, provides insight into how CRABP2 might activate arylfluorosulfates toward site-specific reaction. Treatment of breast cancer cells with probe 4 attenuates nuclear hormone receptor activity mediated by retinoic acid, an endogenous client lipid of CRABP2. Our findings demonstrate that arylfluorosulfates can selectively target single iLBPs, making them useful for understanding iLBP function.

PubMed: 27191344
DOI: 10.1021/jacs.6b02960

Experimental method

X-RAY DIFFRACTION (1.75 Å)