Abstract
Lipoprotein lipase (LPL) purified from bovine milk showed variable abilities to stimulate the binding of low density lipoprotein (LDL) to J774 macrophages. The presence of a 37 kDa protein in the LPL sample seemed to be of importance for its stimulatory capacity. In order to investigate this, we isolated LPL from bovine milk via heparin Sepharose chromatography using a continuous salt gradient. Fractions containing the 37 kDa protein (as shown by SDS/PAGE under reducing conditions) eluted first from the column, followed by the 56 kDa LPL protein. The LPL enzymatic activity co-eluted with the 56 kDa protein, whereas the amount of 37 kDa protein fully paralleled the stimulatory effect on the binding of LDL to J774 cells. Samples not containing the 37 kDa protein were far less effective in stimulating the binding. Western blotting using a monoclonal antibody 5D2 against amino acids 396-405 in the carboxy-terminal domain of LPL, showed that the 37 kDa protein may be the C-terminal domain of LPL, presumably generated by proteolytic degradation of the mature LPL protein by milk proteases during its isolation. Furthermore, the functional mass of LPL for stimulation of the binding of LDL, as determined by radiation inactivation, was shown to be 30.9+/-1.8 kDa. We therefore suggest that cleavage of LPL at protease-sensitive sites causes a conformational change, generating an LPL protein which is more effective in mediating the binding and uptake of lipoproteins by cells.
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- Argraves K. M., Battey F. D., MacCalman C. D., McCrae K. R., Gåfvels M., Kozarsky K. F., Chappell D. A., Strauss J. F., 3rd, Strickland D. K. The very low density lipoprotein receptor mediates the cellular catabolism of lipoprotein lipase and urokinase-plasminogen activator inhibitor type I complexes. J Biol Chem. 1995 Nov 3;270(44):26550–26557. doi: 10.1074/jbc.270.44.26550. [DOI] [PubMed] [Google Scholar]
- Beisiegel U., Weber W., Bengtsson-Olivecrona G. Lipoprotein lipase enhances the binding of chylomicrons to low density lipoprotein receptor-related protein. Proc Natl Acad Sci U S A. 1991 Oct 1;88(19):8342–8346. doi: 10.1073/pnas.88.19.8342. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bengtsson-Olivecrona G., Olivecrona T., Jörnvall H. Lipoprotein lipases from cow, guinea-pig and man. Structural characterization and identification of protease-sensitive internal regions. Eur J Biochem. 1986 Dec 1;161(2):281–288. doi: 10.1111/j.1432-1033.1986.tb10444.x. [DOI] [PubMed] [Google Scholar]
- Bilheimer D. W., Eisenberg S., Levy R. I. The metabolism of very low density lipoprotein proteins. I. Preliminary in vitro and in vivo observations. Biochim Biophys Acta. 1972 Feb 21;260(2):212–221. doi: 10.1016/0005-2760(72)90034-3. [DOI] [PubMed] [Google Scholar]
- Chappell D. A., Fry G. L., Waknitz M. A., Muhonen L. E., Pladet M. W., Iverius P. H., Strickland D. K. Lipoprotein lipase induces catabolism of normal triglyceride-rich lipoproteins via the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor in vitro. A process facilitated by cell-surface proteoglycans. J Biol Chem. 1993 Jul 5;268(19):14168–14175. [PubMed] [Google Scholar]
- Chappell D. A., Inoue I., Fry G. L., Pladet M. W., Bowen S. L., Iverius P. H., Lalouel J. M., Strickland D. K. Cellular catabolism of normal very low density lipoproteins via the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor is induced by the C-terminal domain of lipoprotein lipase. J Biol Chem. 1994 Jul 8;269(27):18001–18006. [PubMed] [Google Scholar]
- Edwards I. J., Goldberg I. J., Parks J. S., Xu H., Wagner W. D. Lipoprotein lipase enhances the interaction of low density lipoproteins with artery-derived extracellular matrix proteoglycans. J Lipid Res. 1993 Jul;34(7):1155–1163. [PubMed] [Google Scholar]
- Eisenberg S., Sehayek E., Olivecrona T., Vlodavsky I. Lipoprotein lipase enhances binding of lipoproteins to heparan sulfate on cell surfaces and extracellular matrix. J Clin Invest. 1992 Nov;90(5):2013–2021. doi: 10.1172/JCI116081. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hendriks W. L., van der Boom H., van Vark L. C., Havekes L. M. Lipoprotein lipase stimulates the binding and uptake of moderately oxidized low-density lipoprotein by J774 macrophages. Biochem J. 1996 Mar 1;314(Pt 2):563–568. doi: 10.1042/bj3140563. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kempner E. S., Schlegel W. Size determination of enzymes by radiation inactivation. Anal Biochem. 1979 Jan 1;92(1):2–10. doi: 10.1016/0003-2697(79)90617-1. [DOI] [PubMed] [Google Scholar]
- Krapp A., Zhang H., Ginzinger D., Liu M. S., Lindberg A., Olivecrona G., Hayden M. R., Beisiegel U. Structural features in lipoprotein lipase necessary for the mediation of lipoprotein uptake into cells. J Lipid Res. 1995 Nov;36(11):2362–2373. [PubMed] [Google Scholar]
- LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
- Liu M. S., Ma Y., Hayden M. R., Brunzell J. D. Mapping of the epitope on lipoprotein lipase recognized by a monoclonal antibody (5D2) which inhibits lipase activity. Biochim Biophys Acta. 1992 Sep 22;1128(1):113–115. doi: 10.1016/0005-2760(92)90264-v. [DOI] [PubMed] [Google Scholar]
- Medh J. D., Bowen S. L., Fry G. L., Ruben S., Andracki M., Inoue I., Lalouel J. M., Strickland D. K., Chappell D. A. Lipoprotein lipase binds to low density lipoprotein receptors and induces receptor-mediated catabolism of very low density lipoproteins in vitro. J Biol Chem. 1996 Jul 19;271(29):17073–17080. doi: 10.1074/jbc.271.29.17073. [DOI] [PubMed] [Google Scholar]
- Mulder M., Lombardi P., Jansen H., van Berkel T. J., Frants R. R., Havekes L. M. Heparan sulphate proteoglycans are involved in the lipoprotein lipase-mediated enhancement of the cellular binding of very low density and low density lipoproteins. Biochem Biophys Res Commun. 1992 Jun 15;185(2):582–587. doi: 10.1016/0006-291x(92)91664-c. [DOI] [PubMed] [Google Scholar]
- Mulder M., Lombardi P., Jansen H., van Berkel T. J., Frants R. R., Havekes L. M. Low density lipoprotein receptor internalizes low density and very low density lipoproteins that are bound to heparan sulfate proteoglycans via lipoprotein lipase. J Biol Chem. 1993 May 5;268(13):9369–9375. [PubMed] [Google Scholar]
- Nilsson-Ehle P., Schotz M. C. A stable, radioactive substrate emulsion for assay of lipoprotein lipase. J Lipid Res. 1976 Sep;17(5):536–541. [PubMed] [Google Scholar]
- Nykjaer A., Bengtsson-Olivecrona G., Lookene A., Moestrup S. K., Petersen C. M., Weber W., Beisiegel U., Gliemann J. The alpha 2-macroglobulin receptor/low density lipoprotein receptor-related protein binds lipoprotein lipase and beta-migrating very low density lipoprotein associated with the lipase. J Biol Chem. 1993 Jul 15;268(20):15048–15055. [PubMed] [Google Scholar]
- Nykjaer A., Nielsen M., Lookene A., Meyer N., Røigaard H., Etzerodt M., Beisiegel U., Olivecrona G., Gliemann J. A carboxyl-terminal fragment of lipoprotein lipase binds to the low density lipoprotein receptor-related protein and inhibits lipase-mediated uptake of lipoprotein in cells. J Biol Chem. 1994 Dec 16;269(50):31747–31755. [PubMed] [Google Scholar]
- O'Brien K. D., Gordon D., Deeb S., Ferguson M., Chait A. Lipoprotein lipase is synthesized by macrophage-derived foam cells in human coronary atherosclerotic plaques. J Clin Invest. 1992 May;89(5):1544–1550. doi: 10.1172/JCI115747. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Politis I. Plasminogen activator system: implications for mammary cell growth and involution. J Dairy Sci. 1996 Jun;79(6):1097–1107. doi: 10.3168/jds.S0022-0302(96)76463-9. [DOI] [PubMed] [Google Scholar]
- Redgrave T. G., Roberts D. C., West C. E. Separation of plasma lipoproteins by density-gradient ultracentrifugation. Anal Biochem. 1975 May 12;65(1-2):42–49. doi: 10.1016/0003-2697(75)90488-1. [DOI] [PubMed] [Google Scholar]
- Rumsey S. C., Obunike J. C., Arad Y., Deckelbaum R. J., Goldberg I. J. Lipoprotein lipase-mediated uptake and degradation of low density lipoproteins by fibroblasts and macrophages. J Clin Invest. 1992 Oct;90(4):1504–1512. doi: 10.1172/JCI116018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Salinelli S., Lo J. Y., Mims M. P., Zsigmond E., Smith L. C., Chan L. Structure-function relationship of lipoprotein lipase-mediated enhancement of very low density lipoprotein binding and catabolism by the low density lipoprotein receptor. Functional importance of a properly folded surface loop covering the catalytic center. J Biol Chem. 1996 Sep 6;271(36):21906–21913. doi: 10.1074/jbc.271.36.21906. [DOI] [PubMed] [Google Scholar]
- Saxena U., Klein M. G., Vanni T. M., Goldberg I. J. Lipoprotein lipase increases low density lipoprotein retention by subendothelial cell matrix. J Clin Invest. 1992 Feb;89(2):373–380. doi: 10.1172/JCI115595. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schoonderwoerd K., Hom M. L., Luthjens L. H., Vieira van Bruggen D., Jansen H. Functional molecular mass of rat hepatic lipase in liver, adrenal gland and ovary is different. Biochem J. 1996 Sep 1;318(Pt 2):463–467. doi: 10.1042/bj3180463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Socorro L., Green C. C., Jackson R. L. Preparation of a homogeneous and stable form of bovine milk lipoprotein lipase. Prep Biochem. 1985;15(3):133–143. doi: 10.1080/10826068508062267. [DOI] [PubMed] [Google Scholar]
- Socorro L., Jackson R. L. Monoclonal antibodies to bovine milk lipoprotein lipase. Evidence for proteolytic degradation of the native enzyme. J Biol Chem. 1985 May 25;260(10):6324–6328. [PubMed] [Google Scholar]
- Williams S. E., Inoue I., Tran H., Fry G. L., Pladet M. W., Iverius P. H., Lalouel J. M., Chappell D. A., Strickland D. K. The carboxyl-terminal domain of lipoprotein lipase binds to the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) and mediates binding of normal very low density lipoproteins to LRP. J Biol Chem. 1994 Mar 25;269(12):8653–8658. [PubMed] [Google Scholar]