• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.315-322
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• 2014

Immobilized lipases were prepared by physical adsorption using lipase AK, AY, AH, PS and R on Amberlite$^{(R)}$XAD$^{(R)}$7 HP resin. With the immobilized lipases (10%), structured lipid was synthesized by enzymatic interesterification of canola oil, palmitic ethyl ester, and stearic ethyl ester in order to study the reaction characteristics. Among the lipase, the highest protein content was obtained from lipase AH (11.41%) before immobilization, while the highest levels of bound protein was observed from immobilized lipase AK (63.91%). Immobilized lipase AK had the highest interesterification activity (38.3% of total saturated fatty acid). Lipase AK was also used for a continuous reaction in which the slow flow of reactant resulted in increased reaction rate. Reusability of immobilized AK, AH and PS increased at the second reaction (120-196.5%). However, the activity of immobilized AK, which had the highest bound protein content (63.91%) decreased after the third reaction, while the activity of immobilized AH and PS was maintained until the sixth reaction.

• Polymer(Korea)
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• v.33 no.3
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• pp.198-202
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• 2009

Oligo(ethylene terephthalate)(OET), oligo(ethylene succinate-co-terephthalate)(OEST) and oligo(butylene succinate-co-terephthalate)(OBST), which are part of the poly(ethylene terephthalate)(PET) oligomer, were synthesized. Degradation test of oligomers carried out by the presence of lipase PS. There were two objectives in the experiment: first, to measure the weight remaining of the PET oligomer as increasing degradation time, and second to examine the degradation mechanism by analyzing the resulting degraded product. In the synthesis of OEST and OBST, by controlling the feed ratio of both OEST and OBST, we were able to obtain oligomer of different composition ratios. The various composition ratios resulted in oligomer of vastly different thermal properties. We observed that both OEST and OBST were degraded using lipase PS, but as the composition of terephthalic acid was increased, the lipase PS became less effective. We confirmed that the lipase PS easily decomposed polyester of the aliphatic compound.

• Bulletin of Food Technology
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• v.7 no.2
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• pp.64-73
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• 1994

Using 20 lipases from various microbial origins medium chain glycerides, namely, mono-, di-, and tri-carproyl glycerols from glycerol and acid were synthesized in isooctane. Enzyme reaction was performed at 0.35 M of capric acid, 0.025M of glycerol and the same mass of silica gel to remove water in 5ml of isooctane with 30mg of lyophilized lipase. Among 20 lipases, eleven lipases showed good synthetic activities, especially lipase from Pseudomonas aeruginosa (Lipase PS), Rhizomucor miehei origined lipase and Chromobacterium viscosum lipase (Lipase CV) showed good activities for production of tricaproylglycerol, while Lipase OF-360 (origined from Candida rugosa) and Lipase D (Rhizopus delemar) were good for production of dicaprolyglycerol. The lipases, especially Lipase PS, have high thermal stability at $ 60^{circ}C$, and optimum pH of lyophilization for dehydrating the lipase was pH 6.5.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.227-235
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• 2013

This study was conducted to prove the effect of irradiation on lipases (lipase AK, lipase AH, lipase PS-D, Lipozyme TLIM, Lipozyme RMIM and Novozyme SP435) which were used for interesterification reaction using batch type reactor. Through such interesterification, structured lipid (1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl, POS) was synthesized by lipase treated with irradiation at different doses (0, 3, 7, 14, 29 and 59 kGy) using canola oil, palmitic ethyl ester (PEE) and stearic ethyl ester (StEE). After the reaction, fatty acid composition of triacylglycerol (TAG) in structured lipid was analyzed to compare the lipase activity. The results showed that activity of the irradiated lipase AH, PS-D and Novozyme SP435 with certain dose (3 kGy) were slightly improved. Such change of lipase activity suggested that irradiation might affect on the interesterification properties. Especially, Lipase AK, Lipozyme TLIM and Lipozyme RMIM after at 3 kGy irradiation showed that content of stearic acid ($C_{18:0}$) was increased while palmitic acid ($C_{16:0}$) decreased in the interesterified products.

• Macromolecular Research
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• v.16 no.7
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• pp.651-658
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• 2008

Poly(butylene succiate) (PBS), poly(butylene succinate-co-L-lactate) (PBSL), and poly(butylene succinate-co-6-hydroxycaproate) (PBSCL) polymers were degraded by lipase $PS^{(R)}$, and the enzymatic degradation mechanism of PBS was analyzed in detail. The enzymatic degradation of PBS gave 4-hydroxybutyl succinate (4HBS) as the main product. An exo-type hydrolysis mechanism was proposed based on this observation. The terminal chain of PBS had conformational similarity to ordinary tri- and diglycerides and could be incorporated as a substrate in the active site of this lipase. The surface adsorption of the lipase was much larger on PBS and its copolymer films than on the other polyester films because the lipase adhered quite strongly to the polymer terminal through a specific adsorption mechanism. Kinetic analysis showed that the total number of surface adsorption points per unit area of PBSL and PBSCL copolymers was larger than that of the PBS homopolymer.

• Genomics & Informatics
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• v.9 no.2
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• pp.79-84
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• 2011

Two initial models of cold-adapted lipase PsLip1 have been constructed, based on homology with the bacterial lipases Chromobacterium viscosum (CvLip) and Pseudomonas cepacia (PcLip), whose X-ray structures have been solved and refined to high resolution. The mature polypeptide chains of these lipases have 84% similarity. The models of Mod1 and Mod2 have been compared with the tertiary structures of CvLip and PcLip, respectively, and analyzed in terms of stabilizing interactions. Several structural aspects that are believed to contribute to protein stability have been compared: the number of conserved salt bridges, aromatic interactions, hydrogen bonds, helix capping, and disulfide bridges. The 3-dimensional structural model of PsLip1 has been constructed in order to elucidate the structural reasons for the decreased thermostability of the enzyme in comparison with its mesophilic counterparts.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.25-30
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• 2002

A lipase of Staphylococcus aureus B56 was purified from a culture supernatant and its molecular weight was estimated to be 45 kDa by SDS-PAGE. The optimum temperature and pH for the hydrolysis of olive oil was $42^{\circ}C$ and pH 8-8.5, respectively. The enzyme was stable up to $55^{\circ}C$ in the presence of $Ca^++$ at pHs 5-11. The lipase gene was cloned using the PCR amplification method. The sequence analysis showed an open reading frame of 2,076 bp, which encoded a preproenzyme of 691 amino acids. The preproenzyme was composed of a signal sequence (37 aa), propeptide (255 aa), and mature enzyme (399 aa). Based on a sequence comparison, lipase B56 constituted of a separate subgroup among the staphylococcal lipase groups, such as S. aureus PS54 and S. haemolyticus L62 lipases, and was distinct from other lipases in their optimum pH and substrate specificity.

• Journal of Korean Medicine Rehabilitation
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• v.15 no.1
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• pp.99-108
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• 2005

Objectives : Patrinia scabiosaefolia (PS) has long been as a remedy for treating infectious diseases in Korea. In the present experiments, the author examined the effects of PS on the cholecystokinin-octapeptide (CCK)-induced pancreatitis (AP) in rats. Methods : Male Wister rats weighing 200 to 250 g were divided into two group. Normal untreated group, in treatment with PS group; PS was administered orally, followed by $75{\mu}g/kg$ CCK subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 days. In treatment with saline group, the protocol was the same as in treatment group with PS. The author determined the pancreatic weight/body weight ratio, the levels of pancreatic heat shock proteins(HSP)60, HSP72 and the secretion of pro-inflammatory cytokines. Results and Conclusion : PS was significantly decreased the pancreatic weight/body weight ratio in CCK-induced AP. PS increased HSP60 and HSP72 compared with CCK-induced AP. Additionally, the secretion of tumor necrosis factor(TNF)-${\alpha}$, interleukin(IL)-$1{\beta}$ and IL-6 the levels of amylase and lipase were lower than that of saline. These results suggest that PS may has a inhibitory effect against CCK-induced AP.

• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.219-224
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• 2009

Two functional modified-butterfats (MF668 and MF866) were synthesized with two blends (6:6:8 and 8:6:6, w/w%) of anhydrous butterfat (ABF), palm stearin (PS) and flaxseed oil (FSO, omega-3) via lipase-catalyzed interesterification reaction. Their flavor characteristic was investigated using electronic nose and SPME-GC/MS analysis. Each flavor pattern of ABF, FSO, MF668 and MF866 was significantly discriminated with first principal component score of 95.16% in PCA plot. In functional modified-butterfats analyzed with SPME-GC/MS, various volatile compounds such as aldehydes, ketones, acids, and alkanes were detected.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.755-758
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• 2006