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991.
992.
Michael W. Fountain Robert Chiovetti Henri Kercret David O. Parrish Jere P. Segrest 《生物化学与生物物理学报:生物膜》1980,596(3):420-425
A method has been developed for the rapid separation of cells in suspension from non-cell associated lipid vesicles in various assays for vesicle-cell interaction. Separation is achieved on a discontinuous Ficoll-Paque gradient. Cells and free vesicles are totally separated, as evidenced by both radiolabelled vesicles, and vesicles containing the fluorescent dye 6-carboxyfluorescein. The main advantages of this method are the rapidity, efficacy, and gentleness of the separation. Viability of the cells remains consistently high (greater than 96%) throughout the separation. Since this method involves a one-step centrifugation, it precludes the necessity for repeated washings of cells which have been incubated with lipid vesicles. 相似文献
993.
994.
Leukotriene A: stereochemistry and enzymatic conversion to leukotriene B 总被引:13,自引:0,他引:13
Olof Rådmark Curt Malmsten Bengt Samuelsson David A. Clark Giichi Goto Anthony Marfat E.J. Corey 《Biochemical and biophysical research communications》1980,92(3):954-961
Leukotriene A was assigned the structure 5(S)--5,6-oxido-7,9--eicosatetraenoic acid by the enzymatic conversion of a synthetic product of known stereochemistry into the naturally occurring isomer of 5(S),12(R)-dihydroxy-6,8,10,14-eicosatetraenoic acid in human polymorphonuclear leukocytes. 相似文献
995.
David G. Bishop Janette R. Kenrick James H. Bayston Athol S. Macpherson Stanley R. Johns 《生物化学与生物物理学报:生物膜》1980,602(2):248-259
The properties of seven monogalactosyldiacylglycerols and six digalactosyldiacylglycerols, isolated from photosynthetic membranes and possessing different levels of fatty acid unsaturation, have been studied by the monolayer technique and compared with those of the fully saturated compounds. In addition, the monolayer properties of sulphoquinovosyldiacylglycerols and phosphatidylglycerols from higher plant chloroplasts, and several hexadecenoic acids have been measured.Monogalactosyldiacylglycerols containing saturated fatty acids form a condensed monolayer similar to that of saturated phosphatidylcholines. The naturally occurring monogalactosyldiacylglycerols, of which the double bond index ranged from 0.6 to 3.9, possessed comparable force-area curves suggesting that headgroup interactions play a more important role in packing behaviour than in phosphatidylcholines. Although digalactosyldiacylglycerols containing fully saturated fatty acids form a more expanded monolayer than the corresponding monogalactosyldiacylglycerols, the degree of expansion of the monolayer due to the presence of unsaturated fatty acids in the naturally occurring digalactosyldiacylglycerols is much less than in monogalactosyldiacylglycerols. Monogalactosyldiacylglycerols and digalactosyldiacylglycerols from a single species have very similar monolayer properties, and the presence of sulphoquinovosyldiacylglycerols and phosphatidylglycerols in the proportions in which they occur in higher plant chloroplasts does not have any condensing effect on a monolayer of galactolipids 相似文献
996.
Cationized ferritin was found to inhibit the lateral mobility of intramembrane proteins in turkey erythrocyte membranes and the activation of adenylate cyclase by the (?)-epinephrine-bound β-adrenergic receptor. It was observed that cationized ferritin has only a small direct effect on the β-receptor and on the adenylate cyclase moiety. It is concluded that the cationized ferritin-induced inhibition of the hormone-dependent cyclase activity results from the inhibition of the lateral mobility of the receptor and therefore a decrease in the bimolecular rate of interaction between the receptor and the enzyme. 相似文献
997.
Preferential solvation of the glucans amylose, pullulan, and dextran in binary dimethyl-sulfoxide/water (DMSO/H2O) solvent mixtures has been measured using gel-permeation chromatography. The preferential solvation behavior of the three glucans in DMSO/H2O solvent mixtures is indistinguishable in the experiments reported. In solvent mixtures with mol ratio DMSO/H2O less than 1:2, all three glucans are solvated preferentially by H2O. The maximum extent of preferential solvation by H2O is about 2.5 mol H2O/mol of glucose residues. When the DMSO/H2O mol ratio exceeds 1:2, DMSO solvates the glucans preferentially to a maximum extent of about 1 mol DMSO/mol of glucose residues. An interpretation of the change in preferential solvation with mixed solvent composition is suggested in terms of the known characteristics of the binary solvent system, and the relationship of preferential solvation, reported here, to the absolute solvation of the glucan chains is discussed. 相似文献
998.
David R. Eyre Haruhisa Oguchi 《Biochemical and biophysical research communications》1980,92(2):403-410
A method is described for quantifying both reducible and mature crosslinking amino acids of collagen. The main crosslinking residue in cartilage, dentine and mature bone was the 3-hydroxypyridinium compound identified by Fujimoto et al. (1–3). Adult articular cartilage contained about one residue per collagen molecule, over forty times the content of the reducible crosslinks. We propose that hydroxypyridinium residues are formed by spontaneous interaction of two residues of hydroxylysino-5-ketonorleucine. This reaction explains the disappearance of reducible crosslinks at maturity and provides a novel mechanism for lateral crosslinking within and between fibrils which may account for some of the unique physical properties of hard tissue collagens. 相似文献
999.
David A. Clark Giichi Goto Anthony Marfat E.J. Corey Sven Hammarström Bengt Samuelsson 《Biochemical and biophysical research communications》1980,94(4):1133-1139
A slow reacting substance, produced by murine mastocytoma cells, has been shown to have the structure 5(S)-hydroxy-6(R)--glutathionyl-7,9,11- leukotriene C, previously referred to as leukotriene C-2) by ultraviolet spectroscopy, amino acid analyses, lipoxygenase conversion and comparisions with a synthetic compound of known structure and stereochemistry. 相似文献
1000.
David E. Moody Jacqueline L. James Edward A. Smuckler 《Biochemical and biophysical research communications》1980,97(2):673-679
Treatment of male rats with carbon tetrachloride, bromotrichloromethane, chloroform, 1,2-dibromoethane, 1-bromo-2-chloroethane, and 1,2-dibromo-3-chloropropane results in a decrease in cytochrome P-450 content and alterations in the relative content of fatty acids in hepatic microsomes. A high correlation was found between the loss of cytochrome P-450, the decrease in arachidonic acid (r=0.93), and the increases in linoleic (r=?0.91) and oleic acids (r=?0.89). 相似文献