http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Soccio, (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Soccio, Mario,Trono, Daniela,Laus, Maura N.,Pastore, Donato 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.4
An improved spectrophotometric assay of phospholipase $A_2$ ($PLA_2$) activity based on the coupled $PLA_2$/lipoxygenase (LOX) reactions using 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine ($PC_{LIN}$) as substrate is reported. The $PLA_2$-mediated release of free linoleate is continuously monitored by following the absorbance increase at 234 nm caused by its conversion into the conjugated diene hydroperoxide catalyzed by the coupled soybean LOX-1 reaction. The new protocol includes the use of Tween 20 ($3{\mu}L/{\mu}mol$ phospholipid) as surfactant and of ethanol ($15{\mu}L/mL$ reaction mixture), that ensure clearness of reaction mixture and linear increase of absorbance in the course of reaction. This method was tested on a purified secretory $PLA_2$ from honey bee venom (HBV-$PLA_2$). The enzyme did not discriminate among $PC_{LIN}$, phosphatidylcholine, and phosphatidylethanolamine, but showed the highest rate using 1,2-dilinoleoyl-sn-glycero-3-phosphatidylcholine ($PC_{DILIN}$). Nevertheless, the use of $PC_{DILIN}$ is not recommended, as it may induce an overestimation of enzyme activity, because not only the free linoleate, but also the reaction product 1-linoleoyl-lysophosphatidylcholine, are known to be oxidized by LOX. HBV-$PLA_2$ showed maximal activity at pH 9.0, hyperbolic kinetics ($K_m$, $74.2{\pm}2.9{\mu}M$; $V_{max}$, $827{\pm}7{\mu}mol/min/mg$ protein) and competitive inhibition ($K_i$ about $5{\mu}M$) by palmityl trifluoromethyl ketone, a classical $PLA_2$ inhibitor. Interestingly, the HBV-$PLA_2$/soybean LOX-1 coupled reactions also allow an accurate assay of $PC_{LIN}$ concentration. In the whole, these results demonstrate that this improved $PLA_2$/LOX assay allows a very accurate, simple, and rapid measurement of enzyme activity and substrate concentration.
-
Mario Soccio,Donato Pastore,Daniela Trono,Maura N. Laus 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.4
An improved spectrophotometric assay of phospholipase A2 (PLA2) activity based on the coupled PLA2/lipoxygenase (LOX) reactions using 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine (PCLIN) as substrate is reported. The PLA2-mediated release of free linoleate is continuously monitored by following the absorbance increase at 234 nm caused by its conversion into the conjugated diene hydroperoxide catalyzed by the coupled soybean LOX-1 reaction. The new protocol includes the use of Tween 20 (3 μL/μmol phospholipid) as surfactant and of ethanol (15 μL/mL reaction mixture), that ensure clearness of reaction mixture and linear increase of absorbance in the course of reaction. This method was tested on a purified secretory PLA2from honey bee venom (HBV-PLA2). The enzyme did not discriminate among PCLIN, phosphatidylcholine, and phosphatidylethanolamine,but showed the highest rate using 1,2-dilinoleoyl-sn-glycero-3-phosphatidylcholine (PCDILIN). Nevertheless,the use of PCDILIN is not recommended, as it may induce an overestimation of enzyme activity, because not only the free linoleate, but also the reaction product 1-linoleoyl-lysophosphatidylcholine,are known to be oxidized by LOX. HBV-PLA2showed maximal activity at pH 9.0, hyperbolic kinetics (Km,74.2±2.9 μM; Vmax, 827±7 μmol/min/mg protein) and competitive inhibition (Ki about 5 μM) by palmityl trifluoromethyl ketone, a classical PLA2 inhibitor. Interestingly, the HBV-PLA2/soybean LOX-1 coupled reactions also allow an accurate assay of PCLIN concentration. In the whole, these results demonstrate that this improved PLA2/LOX assay allows a very accurate, simple, and rapid measurement of enzyme activity and substrate concentration.
-
-
Dynamics of Precise Ethylene Ionomers Containing Ionic Liquid Functionality
Choi, U Hyeok,Middleton, L. Robert,Soccio, Michelina,Buitrago, C. Francisco,Aitken, Brian S.,Masser, Hanqing,Wagener, Kenneth B.,Winey, Karen I.,Runt, James American Chemical Society 2015 Macromolecules Vol.48 No.2
<P>This paper presents the first findings on the molecular dynamics of the remarkable new class of linear and precisely functionalized ethylene copolymers. Specifically, we utilize broadband dielectric relaxation spectroscopy to investigate the molecular dynamics of linear polyethylene (PE)-based ionomers containing 1-methylimidazolium bromide (<B>ImBr</B>) pendants on exactly every 9th, 15th, or 21st carbon atom, along with one pseudorandom analogue. We also employed FTIR spectroscopy to provide insight into local ionic interactions and the nature of the ordering of the ethylene spacers between pendants. Prior X-ray scattering experiments revealed that the polar ionic groups in these ionomers self-assemble into microphase-separated aggregates dispersed throughout the nonpolar PE matrix. We focus primarily on the dynamics of the segmental relaxations, which are significantly slowed down compared to linear PE due to ion aggregation. Relaxation times depend on composition, the presence of crystallinity, and microphase-separated morphologies. Segmental relaxation strengths are much lower than predicted by the Onsager theory for mobile isolated dipoles but much higher than linear PE, demonstrating that at least some <B>ImBr</B> pendants participate in the segmental process. Analysis of the relaxation strengths using the Kirkwood <I>g</I> correlation factor demonstrates that ca. 10–40% of the <B>ImBr</B> ion dipoles (depending on copolymer composition and temperature) participate in the segmental motions of the precise ionomers under study, with the remainder immobilized or having net antiparallel arrangements in ion aggregates.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2015/mamobx.2015.48.issue-2/ma502168e/production/images/medium/ma-2014-02168e_0011.gif'></P>
KISS연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
