Fatty Acyl Sulfonyl Fluoride as an Activity‐Based Probe for Profiling Fatty Acid‐Associated Proteins in Living Cells

Abstract

Fatty acids play fundamental structural, metabolic, functional, and signaling roles in all biological systems. Altered fatty acid levels and metabolism have been associated with many pathological conditions. Chemical probes have greatly facilitated biological studies on fatty acids. Herein, we report the development and characterization of an alkynyl‐functionalized long‐chain fatty acid‐based sulfonyl fluoride probe for covalent labelling, enrichment, and identification of fatty acid‐associated proteins in living cells. Our quantitative chemical proteomics show that this sulfonyl fluoride probe targets diverse classes of fatty acid‐associated proteins including many metabolic serine hydrolases that are known to be involved in fatty acid metabolism and modification. We further validate that the probe covalently modifies the catalytically or functionally essential serine or tyrosine residues of its target proteins and enables evaluation of their inhibitors. The sulfonyl fluoride‐based chemical probe thus represents a new tool for profiling the expression and activity of fatty acid‐associated proteins in living cells.

Design and Evaluation of PROTACs Targeting Acyl Protein Thioesterase 1

“…A study on serine hydrolase degradation using the broadly reactive fluorophosphonate probes and including the aforementioned FP‐PROTAC used alkyl linkers in their PROTAC design, resulting in PROTACs with preference for degradation of lipolytic enzymes like APT2, despite being known to inhibit a large number of serine hydrolases [9a] . The preference of these enzymes for alkyl motifs can also be inferred from the structure of known APT1 inhibitors like palmostatin B, [16] and the previous use of a simple alkyl chain decorated with a sulfonyl fluoride to target several lipid metabolizing enzymes [17] …”

Sulfur(vi) fluorides as tools in biomolecular and medicinal chemistry

“…25). 84 Here, the authors prepared clickable aliphatic sulfonyl fluorides containing either an alkyne-terminated octyl or hexadecyl (i.e., OTSF and HDSF, respectively) groups and evaluated their proteomic reactivity. Treatment of HEK293 cells with the sulfonyl fluoride probes, subsequent CuAAC with rhodamine B-azide and analysis by in-gel fluorescence revealed the longer alkyl chain, HDSF probe, had more efficient labeling of proteins.…”

“…25 ). 84 Here, the authors prepared clickable aliphatic sulfonyl fluorides containing either an alkyne-terminated octyl or hexadecyl ( i.e. , OTSF and HDSF, respectively) groups and evaluated their proteomic reactivity.…”