TY - JOUR

T1 - Activity-Based Protein Profiling Identifies Protein Disulfide-Isomerases as Target Proteins of the Volatile Salinilactones

AU - Jerye, Karoline

AU - Lüken, Helko

AU - Steffen, Anika

AU - Schlawis, Christian

AU - Jänsch, Lothar

AU - Schulz, Stefan

AU - Brönstrup, Mark

N1 - Publisher Copyright: © 2024 The Authors. Advanced Science published by Wiley-VCH GmbH.

PY - 2024/5/15

Y1 - 2024/5/15

N2 - The salinilactones, volatile marine natural products secreted from Salinispora arenicola, feature a unique [3.1.0]-lactone ring system and cytotoxic activities through a hitherto unknown mechanism. To find their molecular target, an activity-based protein profiling with a salinilactone-derived probe is applied that disclosed the protein disulfide-isomerases (PDIs) as the dominant mammalian targets of salinilactones, and thioredoxin (TRX1) as secondary target. The inhibition of protein disulfide-isomerase A1 (PDIA1) and TRX1 is confirmed by biochemical assays with recombinant proteins, showing that (1S,5R)-salinilactone B is more potent than its (1R,5S)-configured enantiomer. The salinilactones bound covalently to C53 and C397, the catalytically active cysteines of the isoform PDIA1 according to tandem mass spectrometry. Reactions with a model substrate demonstrated that the cyclopropyl group is opened by an attack of the thiol at C6. Fluorophore labeling experiments showed the cell permeability of a salinilactone-BODIPY (dipyrrometheneboron difluoride) conjugate and its co-localization with PDIs in the endoplasmic reticulum. The study is one of the first to pinpoint a molecular target for a volatile microbial natural product, and it demonstrates that salinilactones can achieve high selectivity despite their small size and intrinsic reactivity.

AB - The salinilactones, volatile marine natural products secreted from Salinispora arenicola, feature a unique [3.1.0]-lactone ring system and cytotoxic activities through a hitherto unknown mechanism. To find their molecular target, an activity-based protein profiling with a salinilactone-derived probe is applied that disclosed the protein disulfide-isomerases (PDIs) as the dominant mammalian targets of salinilactones, and thioredoxin (TRX1) as secondary target. The inhibition of protein disulfide-isomerase A1 (PDIA1) and TRX1 is confirmed by biochemical assays with recombinant proteins, showing that (1S,5R)-salinilactone B is more potent than its (1R,5S)-configured enantiomer. The salinilactones bound covalently to C53 and C397, the catalytically active cysteines of the isoform PDIA1 according to tandem mass spectrometry. Reactions with a model substrate demonstrated that the cyclopropyl group is opened by an attack of the thiol at C6. Fluorophore labeling experiments showed the cell permeability of a salinilactone-BODIPY (dipyrrometheneboron difluoride) conjugate and its co-localization with PDIs in the endoplasmic reticulum. The study is one of the first to pinpoint a molecular target for a volatile microbial natural product, and it demonstrates that salinilactones can achieve high selectivity despite their small size and intrinsic reactivity.

KW - activity-based protein profiling

KW - natural products

KW - protein disulfide-isomerases

KW - salinilactones

KW - volatiles

UR - http://www.scopus.com/inward/record.url?scp=85186424001&partnerID=8YFLogxK

U2 - 10.1002/advs.202309515

DO - 10.1002/advs.202309515

M3 - Article

AN - SCOPUS:85186424001

VL - 11

JO - Advanced science

JF - Advanced science

SN - 2198-3844

IS - 18

M1 - 2309515

ER -