Showing papers on "Lipase published in 2009"
TL;DR: The presented characterization of the interfacial composition and its consequences provide a new approach for the understanding of lipase reactions at interfaces with direct impact on biotechnological and health care applications.
646 citations
TL;DR: The structure, function, and regulation of lipolytic enzymes with a special emphasis on ATGL are focused on, which create the "lipolysome," a complex metabolic network that contributes to the control of lipid and energy homeostasis.
484 citations
TL;DR: This is the first report on biodiesel synthesis using immobilized E. aerogenes lipase, and there was negligible loss in lipase activity even after repeated use for seven cycles.
Abstract: Transesterification of Jatropha oil was carried out in t-butanol solvent using immobilized lipase from Enterobacter aerogenes. The presence of t-butanol significantly reduced the negative effects caused by both methanol and glycerol. The effects of various reaction parameters on transesterification of Jatropha oil were studied. The maximum yield of biodiesel was 94% (of which 68% conversion was achieved with respect to methyl oleate) with an oil:methanol molar ratio of 1:4, 50 U of immobilized lipase/g of oil, and a t-butanol:oil volume ratio of 0.8:1 at 55°C after 48 h of reaction time. There was negligible loss in lipase activity even after repeated use for seven cycles. To the best of our knowledge this is the first report on biodiesel synthesis using immobilized E. aerogenes lipase.
443 citations
TL;DR: It was shown that immobilized enzymes retain their activities during 10 repeated batch reactions at 25 degrees C, each lasting 24h, which means the developed novel method could have a potential to be used industrially for the production of chemicals requiring immobilized lipases.
267 citations
TL;DR: Candida rugosa lipase was immobilized on magnetic nanoparticles supported ionic liquids having different cation chain length, and retained 60% of its initial activity after 8 repeated batches reaction, while no activity was detected after 6 cycles for the free enzyme.
Abstract: Candida rugosa lipase was immobilized on magnetic nanoparticles supported ionic liquids having different cation chain length (C(1), C(4) and C(8)) and anions (Cl(-), BF(4)(-) and PF(6)(-)). Magnetic nanoparticles Supported ionic liquids were obtained by covalent bonding of ionic liquids-silane on magnetic silica nanoparticles. The particles are superparamagnetic with diameter of about 55 nm. Large amount of lipase (63.89 mg/(100 mg carrier)) was loaded on the support through ionic adsorption. Activity of the immobilized lipase was examined by the catalysis of esterification between oleic acid and butanol. The activity of bound lipase was 118.3% compared to that of the native lipase. Immobilized lipase maintained 60% of its initial activity even when the temperature was LIP to 80 degrees C. In addition, immobilized lipase retained 60% of its initial activity after 8 repeated batches reaction, while no activity was detected after 6 cycles for the free enzyme. (C) 2008 Elsevier B.V. All rights reserved.
255 citations
252 citations
TL;DR: In this paper, magnetic Fe3O4 nanoparticles treated with (3-aminopropyl)triethoxysilane were used as an immobilization material for lipase.
Abstract: In this work, magnetic Fe3O4 nanoparticles treated with (3-aminopropyl)triethoxysilane were used as immobilization material Lipase was covalently bound to the amino-functionalized magnetic nanoparticles by using glutaraldehyde as a coupling reagent with the activity recovery up to 70% and the enzyme binding efficiency of 84% The binding of lipase to the magnetic particles was confirmed by enzyme assays, transmission electron microscopy, X-ray powder diffraction, and Fourier transform infrared spectra Moreover, the immobilized lipase was found to be able to catalyze the transesterification of soybean oil with methanol to produce fatty acid methyl esters (better known as biodiesel) Besides, it was determined that the conversion of soybean oil to biodiesel fuels reached over 90% by the three-step addition of methanol when 60% immobilized lipase was employed Further study showed that the immobilized lipase could be used four times without significant decrease of activity
222 citations
TL;DR: The importance of ATGL as TG lipase within the "lipolytic machinery" and the current knowledge of molecular mechanisms that regulate ATGL activity are focused on.
222 citations
TL;DR: In this paper, the major yeast TG lipase Tgl4, the functional ortholog of the murine adipose Tgl lipase ATGL, is phosphorylated and activated by cyclin-dependent kinase 1 (Cdk1/Cdc28) for early bud formation in late G1 phase of the cell cycle.
220 citations
TL;DR: The combination of structural and biochemical studies indicate that the lid opening is not mediated by temperature but triggered by interaction with lipid substrate, and the first structure of a member of the lipase family I.5 showing an open configuration is reported.
195 citations
TL;DR: Investigation of the roles of HSL, ATGL, and its coactivator CGI-58 in basal and forskolin-stimulated lipolysis in a human white adipocyte model, the hMADS cells suggest that ATGL/CGI-58 acts independently of H SL and precedes its action in the sequential hydrolysis of triglycerides in human hM ADS adipocytes.
TL;DR: The results establish that loss-of-function mutations in LIPG lead to increased HDL-C levels and support the idea that inhibition of endothelial lipase may be an effective mechanism to raise HDL- C.
Abstract: Elevated plasma concentrations of HDL cholesterol (HDL-C) are associated with protection from atherosclerotic cardiovascular disease. Animal models indicate that decreased expression of endothelial lipase (LIPG) is inversely associated with HDL-C levels, and genome-wide association studies have identified LIPG variants as being associated with HDL-C levels in humans. We hypothesized that loss-of-function mutations in LIPG may result in elevated HDL-C and therefore performed deep resequencing of LIPG exons in cases with elevated HDL-C levels and controls with decreased HDL-C levels. We identified a significant excess of nonsynonymous LIPG variants unique to cases with elevated HDL-C. In vitro lipase activity assays demonstrated that these variants significantly decreased endothelial lipase activity. In addition, a meta-analysis across 5 cohorts demonstrated that the low-frequency Asn396Ser variant is significantly associated with increased HDL-C, while the common Thr111Ile variant is not. Functional analysis confirmed that the Asn396Ser variant has significantly decreased lipase activity both in vitro and in vivo, while the Thr111Ile variant has normal lipase activity. Our results establish that loss-of-function mutations in LIPG lead to increased HDL-C levels and support the idea that inhibition of endothelial lipase may be an effective mechanism to raise HDL-C.
TL;DR: In this paper, an alcohol/salt-based aqueous two-phase systems (ATPSs) were used to recover lipase derived from Burkholderia pseudomallei.
TL;DR: A new and simple method has been proposed to prepare magnetic Fe(3)O(4)-chitosan (CS) nanoparticles by cross-linking with sodium tripolyphosphate (TPP), precipitation with NaOH and oxidation with O(2) in hydrochloric acid aqueous phase containing CS and Fe(OH)(2), and these magnetic CS nanoparticles were used to immobilize lipase.
TL;DR: A lipase from Thermomyces lanuginosus and cutinases from Thermobifida fusca and Fusarium solani hydrolysed poly(ethylene terephthalate) (PET) fabrics and films and bis(benzoyloxyethyl) tereplet (3PET) endo-wise as shown by MALDI-Tof-MS, LC-UVD/MS, cationic dyeing and XPS analysis.
TL;DR: CAL-B immobilized on Lewatit at low ionic strength not only behaved similarly to Novozym 435, but also presented some differences that should be due to the exact protocol of the enzyme immobilization in Novozy 435.
Abstract: This paper shows that the properties of lipase B from Candida antarctica (CAL-B) may be easily modulated using different hydrophobic supports to immobilize it (octyl and butyl-agarose, octadecyl-Sepabeads or Lewatit). CAL-B could be fully desorbed from the supports by just incubating the biocatalyst with Triton X-100, although the concentration of detergent necessary was to fully desorb the enzyme varied with the support employed (from 1% for butyl-agarose to 4% for octadecyl-Sepabeads), suggesting that in all cases, the main reason for the enzyme immobilization was hydrophobic interactions. Lewatit VP OC 1600 yielded very different results in terms of activity, selectivity or enantioselectivity in the hydrolysis of rac-2-O-butyryl-2-phenylacetic acid (1) and 3-phenylglutaric acid dimethyl diester (3) compared to the other preparations. For example, in the hydrolysis of 1, Novozym 435 preferred the S-isomer (with an E value higher than 100) whereas all the other preparations preferred the R isomer (e.g. octyl-agarose-CAL-B with E value of 50). In the hydrolysis of 3, Novozym 435 gave S-3-phenylglutaric acid methyl ester with an ee higher than 99%, by coupling the first asymmetric hydrolysis to the enantiospecific hydrolysis of the monoester. CAL-B immobilized on Lewatit at low ionic strength not only behaved similarly to Novozym 435, but also presented some differences that should be due to the exact protocol of the enzyme immobilization in Novozym 435.
TL;DR: A progressive shift in activity from alkaline to acid proteases was observed during larval development, reflecting that alkaline proteases were not longer the main digestive enzymes involved in protein digestion after the development of gastric glands and onset of acidic digestion.
TL;DR: In this article, surface modified nano-sized magnetite (S-NSM) particles have been suggested as a support for the immobilization of enzyme in a study based on the finding that a lipase is strongly adsorbed onto a hydrophobic surface.
Abstract: As a tool for the stable enzyme reuse, enzyme immobilization has been studied for several decades. Surface-modified nano-sized magnetite (S-NSM) particles have been suggested as a support for the immobilization of enzyme in this study. Based on the finding that a lipase is strongly adsorbed onto a hydrophobic surface, NSM particles (8–12 nm) were made hydrophobic by binding of sodium dodecyl sulfate via a sulfate ester bond. Various types of measurements, such as transmission electron microscopy, X-ray diffraction, infrared spectroscopy, vibration sample magnetometer, and thermo gravimetric analysis, were conducted in characterizing S-NSM nanoparticles. S-NSM particles were used for the adsorption of porcine pancreas lipase (PPL). A dodecyl carbon chain is expected to form a spacer between the surface of the NSM and the lipase adsorbed. The immobilized PPL showed the higher specific activity of oil hydrolysis than that of free one. Immobilized PPL could be recovered by magnetic separation, and showed the constant activity during the recycles.
TL;DR: A novel lipase-catalysed direct Mannich reaction has been developed under aqueous conditions in a “one-pot” strategy and Interestingly, these promiscuous reactions can be greatly promoted by water and generally require aromatic aldehydes.
TL;DR: In this paper, a metagenomic library was constructed using cold-sea sediment samples at Edison Seamount and was screened for lipolytic activities by plating on a tricaprylin medium.
Abstract: To search for new cold-active lipases, a metagenomic library was constructed using cold-sea sediment samples at Edison Seamount and was screened for lipolytic activities by plating on a tricaprylin medium. Subsequently, a fosmid clone was selected, and the whole sequence of 36 kb insert of the fosmid clone was determined by shotgun sequencing. The sequence analysis revealed the presence of 25 open reading frames (ORF), and ORF20 (EML1) showed similarities to lipases. Phylogenetic analysis of EML1 suggested that the protein belonged to a new family of esterase/lipase together with LipG. The EML1 gene was expressed in Escherichia coli, and purified by metal-chelating chromatography. The optimum activity of the purified EML1 (rEML1) occurred at pH 8.0 and 25°C, respectively, and rEML1 displayed more than 50% activity at 5°C. The activation energy for the hydrolysis of olive oil was determined to be 3.28 kcal/mol, indicating that EML1 is a cold-active lipase. rEML1 preferentially hydrolyzed triacylglycerols acyl-group chains with long chain lengths of ≥8 carbon atoms and displayed hydrolyzing activities toward various natural oil substrates. rEML1 was resistant to various detergents such as Triton X-100 and Tween 80. This study represents an example which developed a new cold-active lipase from a deep-sea sediment metagenome.
TL;DR: This non-purified lipase in addition to interesting properties showed a reduced production cost making feasible its applicability in many fields, and shows a thermophilic and thermostable behavior, what is not common among lipases from mesophilic filamentous fungi.
TL;DR: The immobilized lipase demonstrated a high enantioselectivity toward (+)-MPGM and it also displayed the improved thermal stability as compared to the free lipase, indicating a high stability in practical operation.
TL;DR: Burkholderia multivorans V2 (BMV2) isolated from soil was found to produce an extracellular solvent tolerant lipase that exhibited maximum stability in n-hexane and was proved to be efficient in synthesis of ethyl butyrate ester under non-aqueous environment.
TL;DR: The cloning and characterisation of a lipase called SUGAR-DEPENDENT1 is described, which is required for TAG breakdown in Arabidopsis thaliana seeds, and the biochemical literature on seed lipases is discussed.
TL;DR: Investigation of the effect of two galactolipids, monogalactosyldiacylglycerol and DGDG, adsorbed at the interface on in vitro digestibility of olive oil by porcine pancreatic lipase provides interesting insights into the influence of the galactoipid headgroup and lecithin on the emulsion interfacial quality which in turn regulates the lipolysis.
Abstract: It is widely known that the interfacial quality of lipid emulsion droplets influences the rate and extent of lipolysis. The aim of this work was to investigate the effect of two galactolipids, monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), adsorbed at the interface on in vitro digestibility of olive oil by porcine pancreatic lipase. The experiments were performed under simulated duodenal conditions in the presence of phosphatidylcholine (lecithin) and bile salts. It was found that emulsions prepared with DGDG had a longer lag phase prior to lipase activation with a decrease in lipolysis rate. In contrast, no inhibitory effect on lipase kinetics was observed in emulsions prepared with MGDG. We postulated that the larger headgroup and more tightly packed molecular organization of DGDG at the interface gave rise to steric hindrance that retarded colipase and lipase adsorption onto the substrate surfaces and hence delayed and reduced lipolysis. It was noted that the lag phase and lipolysis rate strongly depended on the DGDG/lecithin molar ratio in the systems: the higher the molar ratio, the longer the lag phase followed by a reduced lipolysis rate. The ability of DGDG to inhibit bile salt adsorption/displacement was also investigated. The results showed that bile salts did not completely displace DGDG from the interface, explaining the reason why DGDG still possessed inhibitory activity even in the presence of bile salts at a physiological relevant concentration. The results provide interesting insights into the influence of the galactolipid headgroup and lecithin on the emulsion interfacial quality which in turn regulates the lipolysis. The findings potentially could lead to the production of generic foods and drugs designed for regulating dietary fat absorption in the prevention and treatment of obesity and related disorders.
TL;DR: This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries.
Abstract: Lipases are one of the most important industrial biocatalyst which catalyzes the hydrolysis of lipids. It can also reverse the reaction at minimum water activity. Because of this pliable nature, it is widely exploited to catalyze the diverse bioconversion reactions, such as hydrolysis, esterification, interesterification, alcoholysis, acidolysis and aminolysis. The property to synthesize the esters from the fatty acids and glycerol promotes its use in various ester synthesis. The esters synthesized by lipase finds applications in numerous fields such as biodiesel production, resolution of the recemic drugs, fat and lipid modification, flavour synthesis, synthesis of enantiopure pharmaceuticals and nutraceuticals. It plays a crucial role in the food processing industries since the process is unaffected by the unwanted side products. Lipase modifications such as the surfactant coating, molecular imprinting to suit for the non-aqueous ester synthesis have also been reported. This review deals with lipase catalyzed ester synthesis, esterification strategies, optimum conditions and their applications in food processing industries. Key words: Lipase, food applications, ester, esterification, synthesis
TL;DR: An extracellular lipase from Aspergillus niger NCIM 1207 has been purified to homogeneity using ammonium sulfate precipitation followed by phenyl sepharose and Sephacryl-100 gel chromatography and appears to be unique since it cleaved triolein at only 3-position releasing 1,2-diolein.
TL;DR: To address the role of the lid in CRL activity and specificity, the lid sequences from isoenzymes CRL3 and CRL4 in recombinant rCRL1 were substituted, thus obtaining enzymes differing only in this stretch of residues.
Abstract: The fungus Candida rugosa produces multiple lipase isoenzymes (CRLs) with distinct differences in substrate specificity, in particular with regard to selectivity toward the fatty acyl chain length. Moreover, isoform CRL3 displays high activity towards cholesterol esters. Lipase isoenzymes share over 80% sequence identity but diverge in the sequence of the lid, a mobile loop that modulates access to the active site. In the active enzyme conformation, the open lid participates in the substrate-binding site and contributes to substrate recognition. To address the role of the lid in CRL activity and specificity, we substituted the lid sequences from isoenzymes CRL3 and CRL4 in recombinant rCRL1, thus obtaining enzymes differing only in this stretch of residues. Swapping the CRL3 lid was sufficient to confer to CRL1 cholesterol esterase activity. On the other hand, a specific shift in the chain-length specificity was not observed. Chimeric proteins displayed different sensitivity to detergents in the reaction medium.
Patent•
30 Nov 2009
TL;DR: In this paper, detergent compositions comprising at least one lipase enzyme selected from SriII, ScoIIA, ScoIIB, CefII, and variants, thereof are described.
Abstract: Described are detergent compositions comprising at least one lipase enzyme selected from SriII, ScoIIA, ScoIIB, CefII, and variants, thereof. The compositions are useful for removing oily stains from fabric.
TL;DR: Partial characterization indicated that LipEH166 is a novel cold-adapted alkaline lipase, which may belong to a new family of lipolytic enzymes.
Abstract: A new lipase, LipEH166, isolated from an intertidal flat metagenome, showed no amino acid similarity to any known lipolytic enzyme except in the consensus region. This suggested that LipEH166 and its homologues belong to a new family of lipolytic enzymes. Partial characterization indicated that LipEH166 is a novel cold-adapted alkaline lipase.