• 한국미생물·생명공학회지
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• 제21권2호
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• pp.163-170
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• 1993

The effect of substrate micellization on the hydrolysis rate in the production of lysopho-sphatidylcholine (LPC) from phosphatidylcholine (PC) using hog pancreas phospholipase A2(PLA2) was studied. The optimal temperature and pH for the reactions in aqueous phase was found 42C and 7.2, respectively. For a given PC concentration, initial reaction rate was progressively increased with the addition of sodium deoxycholate (DOC), which could transform the bilayer of phospholipids into micellar structure.

• Journal of Microbiology and Biotechnology
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• 제7권4호
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• pp.258-261
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• 1997

For the efficient production of lysophospholipid the hydrolysis of phospholipid using phospholipase $A_1$ from Serratia sp. MK1 was studied in an aqueous-solvent, a two-phase and an emulsion system. Judged on the basis of productivity and the degree of hydrolysis, the yield of lysophospholipid in a two-phase system was found to be better than that obtained in an emulsion system. Among the 13 organic solvents tested phospholipase $A_1$ showed the most efficient catalytic activity and stability in butyl acetate. When 20% phospholipid was used it was completely hydrolyzed in this two-phase system.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 1991년도 춘계학술발표대회 논문집
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• pp.115-121
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• 1991

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.407-413
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• 1996

A novel type of extracellular phospholipase $A_1$ was isolated from Serratia sp. MK1 and purified to homogeneity by ammonium sulfate precipitation, anion exchange and gel filtration chromatography. The purified enzyme was a monomer with a molecular mass of about 43, 000 Da. This enzyme showed the highest lipolytic activity toward phosphatidylserine among the phosphoglycerides tested, and preferentially catalyzed the hydrolysis of the ester bond in phosphatidic acid to lyso-phosphatidic acid. Enzyme activity was completely inhibited by the addition of a chelating agent such as EDTA, and inhibited enzyme activity was fully recovered by the presence of $Ca^{2+}$. This implies that the enzyme requires $Ca^{2+}$ for activity. The enzyme was stable up to $70^{\circ}C$ when incubated for 1 h at pH 8.5, and the optimal pH and temperature were 8.5 and $50^{\circ}C$, respectively.

• 분석과학
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• 제13권5호
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• pp.592-600
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• 2000

담즙내 지방산의 농도와 그 조성이 콜레스테롤의 과포화와 마찬가지로 담석 형성 과정에 관련이 있는 것으로 여겨지고 있다. 본 연구에서는 gas chromatography-mass spectrometry (GC-MS)의 selected ion monitoring (SIM) 방법을 이용하여 담즙내 23종의 지방산 동시 분석을 시도하였다. 전처리 과정의 첫 단계로 유리 지방산과 인지질 지방산을 분리하기 위해 aminopropyl column을 사용하였고 GC-MS에서의 검출을 위하여 유리 지방산은 MSTFA/TMCS 혼합액으로 유도제화를 실시하였으며 인지질 지방산의 경우는 염기를 이용한 가수분해를 실시한 뒤 위와 동일한 과정으로 유도제화하였다. 이 때의 회수율은 61.1-99.0% 이었으며 각각 3.1-25.6%와 3.8-27.0%의 within-a-day와 day-to-day 분석의 RSD 값을 얻었다. 이 방법을 적용하여 정상인과 담석증 환자의 담즙내에 존재하는 유리 및 인지질 지방산의 농도를 알아보았으며 이 때 각 물질들의 농도와 분포가 두 군간에 차이를 나타냄을 알 수 있었다.

• 한국응용과학기술학회지
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• 제4권1호
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• pp.91-97
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• 1987

Because of its more complete hydrolysis and rapid absorption, MCT is expected its usefulness in the diets of patients with malabsorption syndrom. Also, several authors reported that serum cholesterol level was lower after MCT feedings. In this study, rate of each experimental group were fed for 4weeks with 20％ MCT, 20％ corn oil, mixed diet of 10％ MCT and 10％ corn oil, mixed diet of 17％ corn oil and 3％ shortening. After experimental diet, it was measured to growth rate and serum cholesterol, triglyceride and phospholipid level. The results were as follows; 1. The body weight gain was the lowest in MCT group and others were lower than control group. 2. Serum total cholesterol level was the lowest in corn oil group and others were significantly lower than control group. Free cholesterol level was lower in all experimental groups than control group too. 3. Serum HDL-cholesterol level was significantly higher in all experimental groups than control group. 4. The ratio of VLDL, LDL-Cholesterol to HDL-Cholesterol was significantly lower in all experimental groups than control group. 5. Serum triglyceride level was higher in all experimental groups than control group. Serum phospholipid level was significantly in only mixed diet group of corn oil and shortening than control group. 6. The ratio of total cholesterol to phospholipid was significantly lower in corn oil diet group than control group.

• BMB Reports
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• 제33권4호
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• pp.289-293
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• 2000

Annexin I is a 37 kDa member of the annexin family of calcium-dependent phospholipid binding proteins. Annexin I plays regulatory roles in various cellular processes including cell proliferation and differentiation. Recently we found that annexin I is a heat shock protein (HSP) and displays a chaperone-like function. In this paper we investigated the function of annexin I as an ATPase using 1 to 32 amino acids deleted annexin I (${\Delta}-annexin$ I). ${\Delta}-Annexin$ I hydrolyzed ATP as determined by thin layer chromatography. The ability of ATP hydrolysis was inhibited by ADP, GTP and GDP, but not by the AMP, GMP and cAMP. In view of the ATP hydrolyzing function of HSP, the results support the function of annexin I as a HSP.

• Molecules and Cells
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• 제43권3호
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• pp.286-297
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• 2020

Mammalian patatin-like phospholipase domain containing proteins (PNPLAs) play critical roles in triglyceride hydrolysis, phospholipids metabolism, and lipid droplet (LD) homeostasis. PNPLA7 is a lysophosphatidylcholine hydrolase anchored on the endoplasmic reticulum which associates with LDs through its catalytic region (PNPLA7-C) in response to increased cyclic nucleotide levels. However, the interaction of PNPLA7 with LDs through its catalytic region is unknown. Herein, we demonstrate that PNPLA7-C localizes to the mature LDs ex vivo and also colocalizes with pre-existing LDs. Localization of PNPLA7-C with LDs induces LDs clustering via non-enzymatic intermolecular associations, while PNPLA7 alone does not induce LD clustering. Residues 742-1016 contains four putative transmembrane domains which act as a LD targeting motif and are required for the localization of PNPLA7-C to LDs. Furthermore, the N-terminal flanking region of the LD targeting motif, residues 681-741, contributes to the LD targeting, whereas the C-terminal flanking region (1169-1326) has an anti-LD targeting effect. Interestingly, the LD targeting motif does not exhibit lysophosphatidylcholine hydrolase activity even though it associates with LDs phospholipid membranes. These findings characterize the specific functional domains of PNPLA7 mediating subcellular positioning and interactions with LDs, as wells as providing critical insights into the structure of this evolutionarily conserved phospholipid-metabolizing enzyme family.

• Journal of Pharmaceutical Investigation
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• 제31권4호
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• pp.225-232
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• 2001

The present study was carried out to observe the effect of liposome dispersed gel formulation (Lipogel) on topical delivery of ascorbyl palmitate (AsP). Neutral and negatively charged MLV liposomes containing AsP were prepared with dimyristoylphosphadtidylcholine (DMPC) and dicetyl phosphate (DCP), and dispersed to poloxamer gel matrix. In the hydrolysis study in rat's skin homogenates, AsP hydrolyzed to ascorbic acid (AsA) according to the first-order kinetics with the rate constant of $2.46{\times}10^{-2}\;min^{-1}$. In the passive skin penetration study using Franz diffusion cell, lipogel systems exhibited the greater values in the flux $(J_s)$ and the amount penetrated $(Q_p)$ compared to control hydrogels containing diethyleneglycol monoethyl ether $(Transcutol^{\circledR})$ as a solubilizing agent and a penetration enhancer for AsP. The total amount penetrated $(Q_{Total})$, which is expressed as a summation of $Q_P\;and\;Q_L$, for lipogel system was about 1.4 times higher in average than that of control hydrogel. However the amount localized in the skin $(Q_L)$ was similar in both formulations. As a result, lipogel system enhanced the skin penetration of AsP, possibly due to the increase in local concentration of AsP by preferential adsorption of liposome to the skin and the enhancing effect of phospholipid in liposome composition. Moreover it was expected that the penetrated AsP would generate AsA during skin penetration by the skin esterase. In conclusion, lipogel formulation was considered as a good candidate for topical delivery of AsP.

• 한국수산과학회지
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• 제34권3호
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• pp.173-178
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• 2001

저분자 alginate인 HAG-10, HAG-50, HAG-100 및 alginate를 랫드에 35일간 섭취시켰을 때, 혈청중의 지질성분과 동맥경화지수의 측정으로 특성이 가장 좋은 저분자 alginate인 HAG-50의 안전성을 확보하기 위해 랫드에 경구급성독성실험을 실시하였다. 혈청중 total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides 및 phospholipid 함량과 동맥경화지수는$5\%$ 와 $10\%$HAG-50에서 모두 유의적으로 뚜렷히 감소하여 지질대사 개선효과를 나타내었다. HAG-50의 경구급성독성실험을 검토한 결과, 투여할 수 있는 최고 용량인 랫드 체중 kg당 5.0g의 용량에서도 암$\cdot$수 모두 일반상태의 이상 반응과 폐사 및 병리$\cdot$조직학적 이상을 나타내는 예는 전혀 관찰되지 않아서 $LD_{50}$치의 산출이 불가능하였으므로 HAG-50은 아주 안전한 제재임이 검증되었다. 이상의 결과를 종합해 볼 때, 평균분자량 50,000 정도의 저분자 alginate인 HAG-50이 가장 우수한 지질대사 개선효과의 기능적 특성을 발휘하였으며, 경구급성독성실험 에서도 독성이 전혀 없었고, alginate가 가지고 있는 고유의 생리적 기능을 유지 향상시키면서 이용에 제한이 되고 있는 점성을 줄이고 용해도를 높혀서 alginate의 이용성을 높일 수 있는 새로운 형태의 식품소재라고 사료된다.