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The O-arylcarbamate URB597 (cyclohexylcarbamic acid 3'-carbamoylbiphenyl-3-yl ester; also referred to as KDS-4103) is a potent inhibitor of fatty-acid amide hydrolase (FAAH), an intracellular serine hydrolase responsible for the inactivation of the endogenous cannabinoid anandamide. URB597 demonstrates a remarkable degree of selectivity for FAAH over other serine hydrolases (e.g. cholinesterases) or other components of the endocannabinoid system (e.g. cannabinoid receptors). However, in a proteomic-based selectivity screen based on the displacement of fluorophosphonate-rhodamine (FPR) from mouse brain proteins, it was recently shown that URB597 prevents FPR binding to triacylglycerol hydrolase (TGH) with a median inhibitory concentration of 192nM. To determine whether this effect correlates with inhibition of TGH activity, we investigated the ability of URB597 to inhibit triolein hydrolysis in rat liver and heart tissues, which are rich in TGH, as well as white adipose tissue (WAT), which is rich in adipose triacylglycerol lipase (TGL) and hormone-sensitive lipase. The results show that URB597 does not affect triolein hydrolysis in any of these tissues at concentrations as high as 10microM, whereas it inhibits FAAH activity at low nanomolar concentrations. Moreover, intraperitoneal (i.p.) administration of URB597 at doses that maximally inhibit FAAH in vivo (0.3-3mgkg(-1)) exerts no effect on triolein hydrolysis and tissue triacylglycerol (TAG) levels in rat liver, heart or WAT. The results indicate that URB597, while potent at inhibiting FAAH, does not affect TGH and TGL activities in rat tissues.

Abstract In this study, Penicillium sp. section Gracilenta CBMAI 1583 was used to produce lipase under submerged conditions. The enzyme was purified and the biochemical properties of both the crude and purified enzymes were evaluated. Maximum lipase production (1.62 U mL−1) was obtained using olive oil 0.5% (w v−1) after 72 h of cultivation, representing a 90% increase in the lipase initially produced. The enzyme was purified using hydrophobic interaction chromatography (phenyl Sepharose) under conditions which allowed its interfacial activation. The partially purified sample showed an enzyme with esterase activity (65.4 kDa) on α- and β-naphthyl acetate and other with lipase activity (52.9 kDa) on octyl oleate. Optimum activity of crude and purified lipase was observed at pH 4.0 and 70 °C. The purified lipase was activated by NaCl, BaCl 2 , NH 4 Cl, MnSO 4 and MgSO 4 ; it also presented high stability in organic solvents such as hexane, 2.2.4-trimethylpentane, acetone, DMSO and toluene. Maximum enzyme activity was observed with p -nitrophenyl decanoate as substrate; and the enzyme kinetics showed to be directly affected by Triton X-100. The enzyme shows potential application in processes that operate in acid pH, such as treatment of dairy and industry effluents, resolution of esters in the pharmaceutical industry or in the food industry, as well in synthesis reaction under non-aqueous conditions. Highlights • Lipase from Penicillium sp. Section Gracilenta was produced first time with olive oil. • Partial purification showed two lipolytic enzymes such as esterase and lipase. • Interfacial technique provide purified lipase with 52.9 kDa. • Crude and purified lipases showed be thermotolerant enzymes. • Stability in organic solvents suggests it uses in reactions in non-aqueous media. [ABSTRACT FROM AUTHOR]

Background & Aims: Very low density lipoproteins (VLDLs) are triacylglycerol (TG)-rich lipoproteins produced by the human liver. VLDLs derive the majority of their TG cargo from the lipolysis of TG stored in hepatocellular lipid droplets (LDs). Important roles for LDs and the VLDL secretory pathway in the cell culture production of infectious hepatitis C virus (HCV) have been established. We hypothesized that TG lipolysis and VLDL production are impaired during HCV infection so that these cellular processes can be diverted towards HCV production. Methods: We used an HCV permissive cell culture system (JFH-1/HuH7.5 cells) to examine the relationship between TG lipolysis, VLDL assembly, and the HCV lifecycle using standard biochemical approaches. Results: Lipolysis of cellular TG and VLDL production were impaired in HCV infected cells during the early peak of viral infection. This was partially explained by an apparent deficiency of a putative TG lipase, arylacetamide deacetylase (AADAC). The re-introduction of AADAC to infected cells restored cellular TG lipolysis, indicating a role for HCV-mediated downregulation of AADAC in this process. Defective lipolysis of cellular TG stores and VLDL production were also observed in HuH7.5 cells stably expressing a short hairpin RNA targeting AADAC expression, proving AADAC deficiency contributes to these defective pathways. Finally, impaired production of HCV was observed with AADAC knockdown cells, demonstrating a role for AADAC in the HCV lifecycle. Conclusions: This insight into the biology of HCV infection and possibly pathogenesis identifies AADAC as a novel and translationally relevant therapeutic target. [Copyright &y& Elsevier]

Abstract: It is recognized that the majority of very low density lipoprotein (VLDL) associated triacylglycerol (TG) is synthesized from fatty acids and partial acylglycerols generated by lipolysis of intra-hepatic storage rather than made de novo. Triacylglycerol hydrolase (TGH) is involved in mobilizing stored TG. Modulating the ability of TGH to hydrolyze stored lipids represents a potentially regulated and rate limiting step in VLDL assembly. Phosphorylation of lipases and carboxylesterases trigger diverse but functionally significant events. We explored the potential for regulating the mobilization of hepatic TG through phosphorylation of TGH. Insulin is known to suppress VLDL secretion from liver, and glucagon can be considered an opposing hormone. However, neither insulin nor glucagon treatment of hepatocytes led to phosphorylation of TGH or changes in its activity. Augmenting intracellular TG stores by incubations with oleic acid also did not lead to changes in TGH activity. Therefore, changes in phosphorylation state are not a mechanism for regulating TGH activity, access to TG substrate pools or for TGH-mediated contributions to VLDL assembly and secretion. [Copyright &y& Elsevier]

Triacylglycerol hydrolase (TGH) is an enzyme that catalyzes the lipolysis of intracellular stored triacylglycerol (TG). Peroxisomal proliferator-activated receptors (PPAR) regulate a multitude of genes involved in lipid homeostasis. Polyunsaturated fatty acids (PUFA) are PPAR ligands and fatty acids are produced via TGH activity, so we studied whether dietary fats and PPAR agonists could regulate TGH expression. In 3T3-L1 adipocytes, TGH expression was increased 10-fold upon differentiation, compared to pre-adipocytes. 3T3-L1 cells incubated with a PPARγ agonist during the differentiation process resulted in a 5-fold increase in TGH expression compared to control cells. Evidence for direct regulation of TGH expression by PPARγ could not be demonstrated as TGH expression was not affected by a 24-h incubation of mature 3T3-L1 adipocytes with the PPARγ agonist. Feeding mice diets enriched in fatty acids for 3 weeks did not affect hepatic TGH expression, though a 3-week diet enriched in fatty acids and cholesterol increased hepatic TGH expression 2-fold. Two weeks of clofibrate feeding did not significantly affect hepatic TGH expression or microsomal lipolytic activities in wild-type or PPARα-null mice, indicating that PPARα does not regulate hepatic TGH expression. Therefore, TGH expression does not appear to be directly regulated by PPARs or fatty acids in the liver or adipocytes. [Copyright &y& Elsevier]

A total of 39 agricultural products were screened for natural sources of lipases with distinctive positional specificity. Based on this, Cordyceps militaris lipase (CML) was selected and subsequently purified by sequential chromatography involving anion‐exchange, hydrophobic‐interaction, and gel‐permeation columns. As a result of the overall purification procedure, a remarkable increase in the specific activity of the CML (4.733 U/mg protein) was achieved, with a yield of 2.47% (purification fold of 94.54). The purified CML has a monomeric structure with a molecular mass of approximately 62 kDa. It was further identified as a putative extracellular lipase from C. militaris by the partial sequence analysis using ESI‐Q‐TOF MS. In a kinetic study of the CML‐catalyzed hydrolysis, the values of Vmax, Km, and kcat were determined to be 4.86 μmol·min−1·mg−1, 0.07 mM, and 0.29 min−1, respectively. In particular, the relatively low Km value indicated that CML has a high affinity for its substrate. With regard to positional specificity, CML selectively cleaved triolein at the sn‐1 or 3 positions of glycerol backbone, releasing 1,2(2,3)‐diolein as the major products. Therefore, CML can be considered a distinctive biocatalyst with sn‐1(3) regioselectivity. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2744, 2019. [ABSTRACT FROM AUTHOR]