کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9886520 | 1537831 | 2005 | 13 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Differential hydrolysis of molecular species of lipoprotein phosphatidylcholine by groups IIA, V and X secretory phospholipases A2
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Human groups IIA, V and X secretory phospholipases A2 (sPLA2s) were incubated with human HDL3, total HDL and LDL over a range of enzyme and substrate concentrations and exposure times. The residual phosphatidylcholines (PtdChos) were assayed by high performance liquid chromatography with electrospray ionization mass spectrometry (LC/ESI-MS). The enzymes varied markedly in their rates of hydrolysis of the different molecular species and in the production of lysoPtdCho. The sPLA2s were compared at a concentration of 1 μg/ml and an incubation time of 4 h, when all three enzymes showed significant activity. The groups V and X sPLA2 were up to 20 times more reactive than group IIA sPLA2. Group X sPLA2 hydrolyzed arachidonate and linoleate containing species preferentially, while group V hydrolyzed the linoleates in preference to polyunsaturates. In all instances, the arachidonoyl and linoleoyl palmitates were hydrolyzed in preference to the corresponding stearates by group X sPLA2. The group IIA enzyme appeared to hydrolyze randomly all diacyl molecular species. The minor alkylacyl and alkenylacyl glycerophosphocholines (GroPChos) were poor substrates for groups V and X sPLA2s and these phospholipids tended to accumulate. The present study demonstrates a preferential release of arachidonate from plasma lipoprotein PtdCho by group X sPLA2, as well as a relative resistance of polyunsaturated PtdChos to hydrolysis by group V enzyme, which had not been previously documented. The use of lipoprotein PtdCho as substrate with LC/ESI-MS identification of hydrolyzed molecular species eliminates much of the uncertainty about sPLA2 specificity arising from past analyses of fatty acid release from unknown or ill-defined sources.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids - Volume 1736, Issue 1, 5 September 2005, Pages 38-50
Journal: Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids - Volume 1736, Issue 1, 5 September 2005, Pages 38-50
نویسندگان
W. Pruzanski, L. Lambeau, M. Lazdunsky, W. Cho, J. Kopilov, A. Kuksis,