Interaction of lipoprotein lipase with homogeneous lipid emulsions
The central function of lipoprotein lipase (LpL) is to hydrolyze triacylglycerols in chylomicrons and very low density lipoproteins. We have examined the binding of purified milk lipoprotein lipase to homogeneous synthetic lipid emulsions. Emulsions composed of either naturally occurring ester-linke...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
1997-08-01
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| Series: | Journal of Lipid Research |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520371832 |
| _version_ | 1818675759873523712 |
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| author | C E MacPhee R Y Chan W H Sawyer W F Stafford G J Howlett |
| author_facet | C E MacPhee R Y Chan W H Sawyer W F Stafford G J Howlett |
| author_sort | C E MacPhee |
| collection | DOAJ |
| description | The central function of lipoprotein lipase (LpL) is to hydrolyze triacylglycerols in chylomicrons and very low density lipoproteins. We have examined the binding of purified milk lipoprotein lipase to homogeneous synthetic lipid emulsions. Emulsions composed of either naturally occurring ester-linked lipids or the non-hydrolyzable ether analogues were prepared by sonication and pressure extrusion, and fractionated by sucrose density gradient centrifugation. Flotation analysis using the analytical ultracentrifuge indicated that the individual fractions were relatively homogeneous with respect to size with flotation coefficients and molecular weights for the separated fractions ranging from 100 to 1100 S and 5.2 x 10(7) to 6.0 x 10(8), respectively. Purified milk lipoprotein lipase bound with high affinity and in a saturable manner to emulsions prepared from the non-hydrolyzable ether-linked lipid analogues of 1-oleoyl, 2-palmitoyl phosphatidylcholine and triolein. At low concentrations of LpL, the enzyme caused aggregation of the emulsion particles by interparticle cross-linking. At higher LpL concentrations, the flotation coefficient of the emulsions decreased significantly with a concomitant increase in particle density. At saturation, the number of LpL monomers bound to lipid particles of radii 67, 75, and 79 nm was 1315, 1449, and 1466, respectively. The results demonstrate close packing of LpL on the lipid surface and are consistent with there being little disruption to the overall structure of the emulsion particle. |
| first_indexed | 2024-12-17T08:32:42Z |
| format | Article |
| id | doaj.art-f37771727cd54cc68ed23be28639644a |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T08:32:42Z |
| publishDate | 1997-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-f37771727cd54cc68ed23be28639644a2022-12-21T21:56:34ZengElsevierJournal of Lipid Research0022-22751997-08-0138816491659Interaction of lipoprotein lipase with homogeneous lipid emulsionsC E MacPhee0R Y Chan1W H Sawyer2W F Stafford3G J Howlett4Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.The central function of lipoprotein lipase (LpL) is to hydrolyze triacylglycerols in chylomicrons and very low density lipoproteins. We have examined the binding of purified milk lipoprotein lipase to homogeneous synthetic lipid emulsions. Emulsions composed of either naturally occurring ester-linked lipids or the non-hydrolyzable ether analogues were prepared by sonication and pressure extrusion, and fractionated by sucrose density gradient centrifugation. Flotation analysis using the analytical ultracentrifuge indicated that the individual fractions were relatively homogeneous with respect to size with flotation coefficients and molecular weights for the separated fractions ranging from 100 to 1100 S and 5.2 x 10(7) to 6.0 x 10(8), respectively. Purified milk lipoprotein lipase bound with high affinity and in a saturable manner to emulsions prepared from the non-hydrolyzable ether-linked lipid analogues of 1-oleoyl, 2-palmitoyl phosphatidylcholine and triolein. At low concentrations of LpL, the enzyme caused aggregation of the emulsion particles by interparticle cross-linking. At higher LpL concentrations, the flotation coefficient of the emulsions decreased significantly with a concomitant increase in particle density. At saturation, the number of LpL monomers bound to lipid particles of radii 67, 75, and 79 nm was 1315, 1449, and 1466, respectively. The results demonstrate close packing of LpL on the lipid surface and are consistent with there being little disruption to the overall structure of the emulsion particle.http://www.sciencedirect.com/science/article/pii/S0022227520371832 |
| spellingShingle | C E MacPhee R Y Chan W H Sawyer W F Stafford G J Howlett Interaction of lipoprotein lipase with homogeneous lipid emulsions Journal of Lipid Research |
| title | Interaction of lipoprotein lipase with homogeneous lipid emulsions |
| title_full | Interaction of lipoprotein lipase with homogeneous lipid emulsions |
| title_fullStr | Interaction of lipoprotein lipase with homogeneous lipid emulsions |
| title_full_unstemmed | Interaction of lipoprotein lipase with homogeneous lipid emulsions |
| title_short | Interaction of lipoprotein lipase with homogeneous lipid emulsions |
| title_sort | interaction of lipoprotein lipase with homogeneous lipid emulsions |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520371832 |
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