• BMB Reports
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• v.34 no.5
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• pp.457-462
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• 2001

Using the monomolecular film technique, we compared the interfacial properties of Staphylococcus simulans lipase (SSL) and Staphylococcus aureus lipase (SAL). These two enzymes act specifically on glycerides without any detectable phospholipase activity when using various phospholipids. Our results show that the maximum rate of racemic dicaprin (rac-dicaprin) hydrolysis was displayed at pH 8.5, or 6.5 with Staphylococcus simulans lipase or Staphylococcus aureus lipase, respectively The two enzymes interact strongly with egg-phosphatidyl choline (egg-PC) monomolecular films, evidenced by a critical surface pressure value of around $23\;mN{\cdot}m^{-1}$. In contrast to pancreatic lipases, $\beta$-lactoglobulin, a tensioactive protein, failed to inhibit Staphylococcus simulans lipase and Staphylococcus aureus lipase. A kinetic study on the surface pressure dependency, stereoselectivity, and regioselectivity of Staphylococcus simulans lipase and Staphylococcus aureus lipase was performed using optically pure stereoisomers of diglycerides (1,2-sn-dicaprin and 2,3-sn-dicaprin) and a prochiral isomer (1,3-sn-dicaprin) that were spread as monomolecular films at the air-water interface. Both staphylococcal lipases acted preferentially on distal carboxylic ester groups of the diglyceride isomer (1,3-sn-dicaprin). Furthermore, Staphylococcus simulans lipase was found to be markedly stereoselective for the sn-3 position of the 2,3-sn-dicaprin isomer.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.181-188
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• 2011

This study was carried out to estimate beneficial effects of Foeniculi fructus water extract on activities of key enzymes such as lipoprotein lipase (LPL), acyl-CoA synthetase (ACS), and hormone sensitive lipase (HSL) on lipid metabolism related with obesity. LPL and ACS were extracted from the epididymal adipose tissue and liver of C57BL/6J normal and obese mouse. Foeniculi fructus water extract treatment significantly reduced the activity of normal and obese LPL. When 100 ppm of Foeniculi fructus water extracts were tested, they decreased obese LPL activity by 12.0%. Foeniculi fructus water extract activated obese ACS activity by 7-fold compared with control at 1,000 ppm concentration. Expression of HSL mRNA was increased in Foeniculi fructus water extracts treated cells compared with non treated cells. All things considered, Foeniculi fructus water extract efficiently inhibits the influx of fatty acid into the cell, and activates metabolic process that uses fatty acids flowing as an energy source. Thus, it suggest that Foeniculi fructus water extract may have great potential as a novel anti-obesity agent.

• Korean Journal of Pharmacognosy
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• v.43 no.3
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• pp.201-205
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• 2012

In the course of screening pancreatic lipase inhibitory activity, total methanolic extract and EtOAc-soluble fraction of Duchesnea chrysantha showed significant inhibitory activity. Further fractionation and isolation of the EtOAc-soluble fraction resulted in five compounds, which were identified as trans-tiliroside (1), isovitexin (2), kaempferol-8-O-${\beta}$-glucoside (3), kaempferol-3-O-${\beta}$-glucoside (4) and quercetin-3-O-${\beta}$-glucoside (5). All the five flavonoids derivatives were first reported from this plant but showed weak inhibitory effects on pancreatic lipase activity.

• Applied Biological Chemistry
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• v.14 no.3
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• pp.207-212
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• 1971

An enzyme preparation from a newly isolated Candida that showed a high lipase activity was subjected to examination of its reaction rate under various conditions. The original and a diluted enzyme solutions showed the zero order curve starting at the point of 50 minutes in time. When PVA was used as an emulsifyer more activity was observed than the case of gum arabic. The optimal temperature and pH were $37{\sim}40^{\circ}C$ and 7.0, respectively. Oleic acid as a fatty acid conferred on the enzyme an inhibitory action while calcium ion a positive one. Sodium cholate yielded an increase in reaction rate at the first stage.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.523.2-523
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• 1986

The hydrolysis of olive oil was attempted with immobilized C. rugosa lipase in the reverse phase solvent system. (i.e. immobilized wet particles is dispersed in continuous phase olive oil or organic solvents containing olive oil). Sephadex LH-20 and LH-60 were used as the supports that can be used in organic solvents. The water content of wet particles of sephadex LH-20 and LH-60 were about 72% (w/w) and 85% (w/w), respectively Both swollen gels with 0.05M buffers adsorbed about 18% of lipase dissolved. They were easily dispersed in liquid olive oil or in organic solvents. The effects of organic solvents on the stability and catalytic activity of the lipase have been examined. The results revealed that isooctane is superior to the other solvents examined for enzymatic fat spliting in reverse phase system. Kinetics of enzymatic hydrolys of olive oil by immobilized lipase has been investigated in a batch reactor. Effects of pH and temperature on the lipase were studied. The substrate concentration was influenced positively on the thermal stability.

• Journal of Applied Biological Chemistry
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• v.48 no.2
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• pp.84-88
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• 2005

To develop functional food and anti-obesity drug through inhibition of dietary lipid absorption, inhibitory effects of herb extracts on pancreatic lipase were investigated. Due to high yield and simplicity of isolation, lipase inhibitor (ELI) was isolated from ethyl acetate extract of Eugenia aromaticum, which showed highest inhibitory activity, and characterized for development of novel functional material. Stability of ELI at high temperature and low pH was investigated. Results showed ELI is relatively stable under thermal and acidic conditions, reversible, and noncompetitive inhibitor of pancreatic lipase.

• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.477-482
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• 2014

We immobilized Thermomyces lanuginosus lipase to catalyze transesterification reaction in DMF. This lipase was selected after screening among other commercial lipases. We found that prepared immobilized lipase is particularly useful for preparation of 6-O-acylsucrose with higher conversion rate even in 10 g scale. Several solvents were evaluated for selective transesterification reaction. We noticed that the immobilized lipase retained more than 80 % activity after 5 cycles of 96 h reaction. A general method was also developed to purify the products using simple crystallization and precipitation process. Furthermore, 6-O-vinyladipoylsucrose was subjected to synthesis of the corresponding polymer by radical initiator. The sucrose branched polymer can be used further for evaluation of its biodegradability and other biological applications.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.4
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• pp.569-575
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• 2018

Objective: This experiment was conducted to investigate the effects of chromium picolinate (CrP) on fat deposition, genetic expression and enzymatic activity of lipid metabolism-related enzymes. Methods: Two hundred forty one-day-old Ross broilers were randomly divided into 5 groups with 4 replicates per group and 12 Ross broiler chicks per replicate. The normal control group was fed a basal diet, and the other groups fed the same basal diet supplemented with 0.1, 0.2, 0.4, and 0.8 mg/kg CrP respectively. The experiment lasted for 21 days. Results: Added CrP in the basal diet decreased the abdominal fat, had no effects on subcutaneous fat thickness and inter-muscular fat width; 0.2 mg/kg CrP significantly decreased the fatty acid synthase (FAS) enzymatic (p<0.05); acetyl-CoA carboxylase (ACC) enzymatic activity decreased in all CrP groups (p<0.05); hormone-sensitive lipase (HSL) enzymatic activity also decreased, but the change was not significant (p>0.05); 0.4 mg/kg CrP group significantly decreased the lipoprotein lipase (LPL) enzymatic activity. FAS mRNA expression increased in all experimental groups, and the LPL mRNA expression significantly increased in all experimental groups (p<0.05), but not 0.2 mg/kg CrP group. Conclusion: The results indicated that adding CrP in basal diet decreased the abdominal fat percentage, had no effects on subcutaneous fat thickness and inter-muscular fat width, decreased the enzymatic activity of FAS, ACC, LPL and HSL and increased the genetic expression levels of FAS and LPL.

• Analytical Science and Technology
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• v.30 no.3
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• pp.138-145
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• 2017

Microwave-assisted organic synthesis has gained a remarkable interest over the past years because of its advantages - (i) rapid energy transfer and superheating, (ii) higher yield and rapid reaction, (iii) cleaner reactions. Ionic liquids are well known for their unique properties such as negligible vapor pressure and high thermal stability. With these properties, ionic liquids have gained increasing attention as green, multi-use reaction media. Recently, ionic liquids have been applied as reaction media for biocatalysis. Lipase-catalyzed reactions in ionic liquids provide high activity and yield compared to conventional organic solvents or solvent free system. Since polar molecules are generally good absorbent to microwave radiation, ionic liquids were investigated as reaction media to improve activity and productivity. In this study, therefore, the effect of microwave irradiation in ionic liquids was investigated on lipase catalyzed reactions such as benzyl acetate synthesis and caffeic acid phenethyl ester synthesis. Comparing to conventional heating, microwave heating showed almost the same final conversion but increased initial reaction rate (3.03 mM/min) compared to 2.11 mM/min in conventional heating at $50^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.546-554
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• 2019

This study, for the first time, reports the functional expression of lipase B derived from the yeast Candida antarctica (CALB) in Corynebacterium strain using the Escherichia coli plasmid PK18. The CALB gene fragment encoding a 317-amino-acid protein was successfully obtained from the total RNA of C. antarctica. CALB was readily produced in the Corynebacterium strain without the use of induction methods described in previous studies. This demonstrated the extracellular production of CALB in the Corynebacterium strain. CALB produced in the Corynebacterium MB001 strain transformed with pEC-CALB recombinant plasmid exhibited maximum extracellular enzymatic activity and high substrate affinity. The optimal pH and temperature for the hydrolysis of 4-nitrophenyl laurate by CALB were 9.0 and 40℃, respectively. The enzyme was stable at pH 10.7 in the glycine-KOH buffer and functioned as an alkaline lipase. The CALB activity was inhibited in the presence of high concentration of Mg²⁺, which indicated that CALB is not a metalloenzyme. These properties are key for the industrial application of the enzyme.