TY - JOUR
T1 - α-Cyclodextrin extracts diacylglycerol from insect high density lipoproteins
AU - Jouni, Zeina E.
AU - Zamora, Jorge
AU - Snyder, Marcus
AU - Montfort, William R.
AU - Weichsel, Andrzej
AU - Wells, Michael A.
PY - 2000/6
Y1 - 2000/6
N2 - α-Cyclodextrins are water-soluble cyclic hexamers of glucose units with hydrophobic cavities capable of solubilizing lipophiles. Incubating α- cyclodextrin with high density lipophorin from Manduca sexta or Bombyx mori resulted in a cloudy, turbid solution. Centrifugation separated a pale yellowish precipitate. Thin-layer chromatography analysis of the lipid extract of the precipitate showed that the major lipid was diacylglycerol, while KBr density gradient analysis of the supernatant demonstrated the presence of a lipid-depleted very high density lipophorin. Transfer of diacylglycerol from lipophorin to cyclodextrin was specific to α- cyclodextrin and was not observed with β- or γ-cyclodextrins. pH had no effect on diacylglycerol transfer to α-cyclodextrin. However, the transfer was strongly dependent on the concentration of α-cyclodextrin and temperature. Increasing the concentration of α-cyclodextrin in the incubation mixture was associated with the formation of increasingly higher density lipophorins. Thus, at 20, 30, and 40 mMand α-cyclodextrin, the density of B. mori lipophorin increased from 1.107 g/ml to 1.123, 1.148, and 1.181 g/ml, respectively. At concentrations greater than 40 mM, α- cyclodextrin had no further effect on the density of lipophorin. α- Cyclodextrin removed at most 83-87% of the diacylglycerol present in lipophorin. Temperature played an important role in altering the amount of diacylglycerols transferred to α-cyclodextrin. At 30 mM α-cyclodextrin, the amount of diacylglycerol transferred at different temperatures was 50% at 4°C, 41% at 15°C, 20% at 28°C, and less than 3% at 37°C. We propose that diacylglycerol transfers to α-cyclodextrin via an aqueons diffusion pathway and that the driving force for the transfer is the formation of an insoluble α-cyclodextrin-diacylglycerol complex.
AB - α-Cyclodextrins are water-soluble cyclic hexamers of glucose units with hydrophobic cavities capable of solubilizing lipophiles. Incubating α- cyclodextrin with high density lipophorin from Manduca sexta or Bombyx mori resulted in a cloudy, turbid solution. Centrifugation separated a pale yellowish precipitate. Thin-layer chromatography analysis of the lipid extract of the precipitate showed that the major lipid was diacylglycerol, while KBr density gradient analysis of the supernatant demonstrated the presence of a lipid-depleted very high density lipophorin. Transfer of diacylglycerol from lipophorin to cyclodextrin was specific to α- cyclodextrin and was not observed with β- or γ-cyclodextrins. pH had no effect on diacylglycerol transfer to α-cyclodextrin. However, the transfer was strongly dependent on the concentration of α-cyclodextrin and temperature. Increasing the concentration of α-cyclodextrin in the incubation mixture was associated with the formation of increasingly higher density lipophorins. Thus, at 20, 30, and 40 mMand α-cyclodextrin, the density of B. mori lipophorin increased from 1.107 g/ml to 1.123, 1.148, and 1.181 g/ml, respectively. At concentrations greater than 40 mM, α- cyclodextrin had no further effect on the density of lipophorin. α- Cyclodextrin removed at most 83-87% of the diacylglycerol present in lipophorin. Temperature played an important role in altering the amount of diacylglycerols transferred to α-cyclodextrin. At 30 mM α-cyclodextrin, the amount of diacylglycerol transferred at different temperatures was 50% at 4°C, 41% at 15°C, 20% at 28°C, and less than 3% at 37°C. We propose that diacylglycerol transfers to α-cyclodextrin via an aqueons diffusion pathway and that the driving force for the transfer is the formation of an insoluble α-cyclodextrin-diacylglycerol complex.
KW - Bombyx mori
KW - Fluid-phase transfer
KW - Lipophorin
KW - Manduca sexta
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M3 - Article
C2 - 10828085
AN - SCOPUS:0033934623
SN - 0022-2275
VL - 41
SP - 933
EP - 939
JO - Journal of Lipid Research
JF - Journal of Lipid Research
IS - 6
ER -