Chemical Proteomic Analysis of Serine Hydrolase Activity in Niemann-Pick Type C Mouse Brain

Abstract

The endocannabinoid system (ECS) is considered to be an endogenous protective system in various neurodegenerative diseases. Niemann-Pick type C (NPC) is a neurodegenerative disease in which the role of the ECS has not been studied yet. Most of the endocannabinoid enzymes are serine hydrolases, which can be studied using activity-based protein profiling (ABPP). Here, we report the serine hydrolase activity in brain proteomes of a NPC mouse model as measured by ABPP. Two ABPP methods are used: a gel-based method and a chemical proteomics method. The activities of the following endocannabinoid enzymes were quantified: diacylglycerol lipase (DAGL) α, α/β-hydrolase domain-containing protein 4, α/β-hydrolase domain-containing protein 6, α/β-hydrolase domain-containing protein 12, fatty acid amide hydrolase, and monoacylglycerol lipase. Using the gel-based method, two bands were observed for DAGL α. Only the upper band corresponding to this enzyme was significantly decreased in the NPC mouse model. Chemical proteomics showed that three lysosomal serine hydrolase activities (retinoid-inducible serine carboxypeptidase, cathepsin A, and palmitoyl-protein thioesterase 1) were increased in Niemann-Pick C1 protein knockout mouse brain compared to wild-type brain, whereas no difference in endocannabinoid hydrolase activity was observed. We conclude that these targets might be interesting therapeutic targets for future validation studies.

Structural Determination of Lysosphingomyelin-509 and Discovery of Novel Class Lipids from Patients with Niemann–Pick Disease Type C

“…The hydrolysis to N -acyl-serines might occur via multiple pathways [19]. A recent report by Van Rooden et al showed an increase in α/β-hydrolase domain-containing protein, one of the hydrolysing enzymes for N -acyl-phosphatidylethanolamine in Npc1 (-/-) mouse brains [20]. However, there is only one report about the existence of N -acyl-phosphatidylserines and N -acyl-serines in humans [21].…”

Activation of Tenofovir Alafenamide and Sofosbuvir in the Human Lung and Its Implications in the Development of Nucleoside/Nucleotide Prodrugs for Treating SARS-CoV-2 Pulmonary Infection

“…Most of these enzymes exert their catalytic functions via nucleophilic attacking the carbonyl carbon atom of the carboxylic ester through its serine-histidine-aspartate triad [18]. Activity-based protein profiling (ABPP) is a powerful chemoproteomic strategy for assessing the catalytic activity of target enzymes in native biological systems [17][18][19][20]. In this study, we conducted an ABPP study using the desthiobiotin-fluorophosphonate (FP) probe [18] to globally assess the catalytic activity of serine hydrolases in human lung S9 (HlungS9) fractions in an effort to identify hydrolyses that can be targeted for activating an ester prodrug in the human lung.…”

Rapid Solid-Phase Construction of Serine Hydrolase Probes Results in Selective Activity-Based Probes for Acyl Protein Thioesterases-1/2

“…A mouse brain lysate was chosen as a suitable proteome for screening because it contains a wide variety of pharmacologically interesting SHs. Previous studies have identified between approximately 25 and 40 different SHs in this lysate and, conveniently, the retention of several of these on SDS-PAGE is known. − Hence, the cytosolic and membrane fractions of mouse brain lysates were pretreated with compounds 4a–6f and residually active SHs were labeled with FP-Rh (Figure A). Interestingly, this competitive ABPP experiment revealed that five library members (the three triazole ureas 4f , 5f and 6f , and two NHS-carbamates 5b and 6b ) showed selective inhibition of two close-running gel bands that have previously been identified as APT-1/2 (Figure A) .…”