http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
돼지 Lecithin : Cholesterol Acyltransferase 의 화학적 성질
최명숙,박용복 ( Myung Sook Choi,Yong Bok Park ) 생화학분자생물학회 1991 BMB Reports Vol.24 No.1
Amino acid residues of lecithin: cholesterol acyltransferase from hog plasma were modified with various chemicals in order to identify the functionally important amino acid residues of the enzyme. At least one sulfhydryl group was found to be essential for the catalytic activity and all four of the sulfhydryl groups may be involved in the self-association process at high enzyme concentrations in vitro. During the self-association process, the sulfhydryl groups may participate in the intermolecular disulfide bond formation. More than one half of tryptophan residues of the enzyme was exposed to the aqueous environment under non-denaturing conditions. Fluorescence quenching studies showed that apolipopotein-AI in the high-density lipoproteins is one of the major contributors in the substrate binding of the enzyme. This interaction seems to be mediated mainly by the hydrophobic interaction between the substrate and the enzyme. The enzyme activity was sensitively modified by thiol, seryl and histidyl modifiers, indicating an importance of those amino acid residues in the function of the enzyme.
최명숙,박용복 ( Myung Sook Choi,Yong Bok Park ) 생화학분자생물학회 1989 BMB Reports Vol.22 No.2
Milk was tested whether it plays roles as a cholesterol-lowering agent in suckling rabbits since a serum cholesterol content of newborn rabbit was increased till second week then gradually decreased during lactation. Cholesterol content of fetal rabbit aorta was compared after the aorta was cultured in the media containing human breast milk and WHHL (Watanabe heritable hyperlipidemic) rabbit LDL. In precultured aorta in the medium containing milk prior to culture with 5% hyperlipidemic LDL media, the aortic cholesterol content was similar to that of the aorta cultured in the human breast milk only. However, the cholesterol content of the aorta cultured in 5% hyperlipidemic LDL media without preculture in the human breast milk was significantly higher than that of the precultured aorta in the human milk. This suggests that milk led the fetal aorta resistent to cholesterol-elevating effect by an unknown mechanism.
최명숙,박용복,Choi, Myung-Sook,Park, Yong-Bok 생화학분자생물학회 1989 한국생화학회지 Vol.22 No.2
출생 때에 토끼는 성숙한 토끼보다 비교적 높은 혈중 콜레스테롤을 포함하고 있으며 그 농도는 수유에 따라 증가하여 수유 2주일에 최대치를 보이다가 수유기간이 끝나는 4주째에는 정상농도로 돌아가게 된다. 사람의 모유 또는 와타나베토끼(유전적으로 혈중 콜레스테롤이 비정상적으로 높은 토끼)의 혈청으로부터 분리한 저밀도 리포단백질을 배지에 포함시켜 출생전 토끼의 대동맥을 조직 배양할 경우 대동액내에 포함되어 있는 콜레스테롤 양의 변화를 관찰하였다. 사람의 모유를 함유한 배지에 먼저 배양한 후 와타나베토끼의 저밀도 리포단백질을 함유한 배지로 옮겨 배양했을 때 출생전 토끼 대동맥내 콜레스테롤 농도는 사람의 모유에서만 같은 기간동안 배양한 대동맥에서와 비슷했다. 그러나 사람의 모유에서 먼저 배양하지 않고 와타나베토끼의 저밀도 리포단백질을 함유한 배지에서만 배양한 대동맥에서는 훨씬 높은 콜레스테롤 농도를 보여주었다. 이 결과로 미루어 보아 사람의 모유가 대동액내의 콜레스테롤 축척을 막아주는 역할을 한다는 사실을 추측할 수 있다. Milk was tested whether it plays roles as a cholesterol-lowering agent in suckling rabbits since a serum cholesterol content of newborn rabbit was increased till second week then gradually decreased during lactation. Cholesterol content of fetal rabbit aorta was compared after the aorta was cultured in the media containing human breast milk and WHHL (Watanabe heritable hyperlipidemic) rabbit LDL. In precultured aorta in the medium containing milk prior to culture with 5% hyperlipidemic LDL media, the aortic cholesterol content was similar to that of the aorta cultured in the human breast milk only. However, the cholesterol content of the aorta cultured in 5% hyperlipidemic LDL media without preculture in the human breast milk was significantly higher than that of the precultured aorta in the human milk. This suggests that milk led the fetal aorta resistent to cholesterol-elevating effect by an unknown mechanism.
Chemical Modifications of Lecithin: Cholesterol Acyltransferase from Hog Plasma
최명숙,박용복,Choi, Myung-Sook,Park, Yong-Bok Korean Society for Biochemistry and Molecular Biol 1991 한국생화학회지 Vol.24 No.1
Amino acid residues of lecithin:cholesterol acyltransferase form hog plasma were modified with various chemicals in order to identify the functionally important amino amino acid residues of the enzyme. At least one sulfhydryl group was found to be essential for the catalytic activity and all four of the sulfhydryl groups may be involved in the self-association process at high enzyme concentration in vitro. During the self-association process, the sulfhydryl groups may participate in the intermolecular disulfide bond formation. More than one half of tryptophan residues of the enzyme was exposed to the aqueous environment under non-denaturing conditions. Fluorescence quenching studies showed that apolipoprotein-AI in the high-density lipoproteins is one of the major contributors in the substrate binding of the enzyme. This interaction seems to be mediated mainly by the hydrophodic interaction between the substrate and the enzyme. The enzyme activity was sensitively modified by thiol, seryl and histidyl modifiers, indication an importance of those amino acid residues in the function of the enzyme. 돼지혈장으로부터 분리한 lecithin : cholesterol acyltransferase의 아미노산 잔기들을 여러 가지 화학물질로 변환시킴으로서 이 효소의 촉매기능에 중요한 역할을 담당하는 아미노산 잔기들을 규명하려 하였다. 최소한 한 개의 thiol기가 이 효소의 촉매반응에 필요하며 높은 효소농도에서는 네 개 모두의 thiol기가 분자간 disulfide 결합을 형성함으로서 효소분자간의 결합에 관여할 것으로 추정된다. 전체 tryptophan 잔기의 절반 이상이 효소분자의 표면에 노출되어 있으며 이러한 소수성 아미노산 잔기들이 이 효소의 기질인 high-density lipoprotein 표면의 apolipoprotein-AI과 소수성 결합에 관여함으로서 효소-기질 결합에 참여할 것으로 추정된다. 이 효소의 역가는 serine, thiol 그리고 histidine 잔기를 변환하는 화학물질에 의해 민감하게 저해됨으로서 이러한 아미노산 잔기들이 이 효소의 촉매반응에 관여함을 제시해주고 있다.
박용복,정남호,김홍석,최명숙 ( Yong Bok Park,Nam Ho Jeoung,Hong Seok Kim,Myung Sook Choi ) 생화학분자생물학회 1992 BMB Reports Vol.25 No.5
Cholesteryl ester (CE) transfer between lipoproteins was studied in vitro in various incubation mixtures containing isolated lipoproteins and an inhibitor of lecithin: cholesterol acyltransferase (LCAT). Isolated high-density lipoproteins (HDL) exhibited a significant amount of cholesteryl ester transfer activity. In incubations of HDL with very low-density lipoproteins (VLDL) at 37℃, decrease of free cholesterol (FC) in human VLDL was mainly associated with decrease of cholesteryl ester (CE) in HDL. In this system, FC of human VLDL was transferred to human HDL, but could not be esterified due to LCAT inhibitor resulting in an accumulation of FC in HDL fraction. However, CE in human HDL was transferred to human VLDL during the incubation. This appears to be the major mean for keeping cholesterol equilibrium between lipoproteins. Another results support that cholesteryl ester transfer protein (CETP) promotes both the exchange and net transfer of cholesterol species between lipoproteins and that the net transfer proceeds in the direction of HDL to lower density lipoproteins, which are well agreed with the previous reports. In efforts to simplify the CETP assay method, cholesteryl-[^(14)C]-oleate in reconstituted HDL (R_(HDL)) covalently bound to agarose beads was used as a CE donor. This simple evaluation of CE transfer activity did not require the time-consuming ultracentrifugation before and after the incubation, that has been used in the previous assay. It also eliminates the use of heparine-MnC1₂ or dextran sulfate-MgC1₂ for the precipitation of LDL or VLDL, that is relatively costly.
권은영,Yun-Young Cho,도경민,Hye-Jin Kim,Seon-Min Jeon,Yong-Bok Park,이미경,Tae Sun Min,최명숙 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.5
This study was carried out to investigate whether dietary vitamin E and ferulic acid (FA) can exert possible interactions on preventions of hypercholesterolemia and atherogenic lesion formation in C57BL/65 apolipoprotein E-deficient (apo E−/−) mice. Four-week-old male apo E−/− mice were randomly divided into three groups and given one of three types of Western diets with various amounts of vitamin E (0.02%, 0%, or 0.2%) for 15 weeks. FA was added to vitamin E-free Western diet and vitamin E-rich Western diet at the 0.02% level. The plasma total cholesterol concentration was significantly lowered when FA was added to the vitamin E-free and vitamin E-rich Western diet as compared to the normal vitamin E Western diet (0.02% vitamin E), and this was accompanied with a decreased hepatic acyl-coenzyme A:cholesterol acyltransferase activity. The hepatic and erythrocyte thiobarbituric acid-reactive substances levels were significantly lowered when FA was added to the vitamin E-rich Western diet, which was attributable to increased activities of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) and paraoxonase. Accordingly, vitamin E and/or FA are beneficial for prevention of hypercholesterolemia and atherogenesis in apo E−/− mice. In particular, dietary FA exhibited an anti-atherosclerotic property, and this effect was synergistically enhanced with the vitamin E supplement.