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Lipoprotein lipase is active as a monomer

Lipoprotein lipase (LPL), the enzyme that hydrolyzes triglycerides in plasma lipoproteins, is assumed to be active only as a homodimer. In support of this idea, several groups have reported that the size of LPL, as measured by density gradient ultracentrifugation, is ∼110 kDa, twice the size of LPL...

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Autores principales: Beigneux, Anne P., Allan, Christopher M., Sandoval, Norma P., Cho, Geoffrey W., Heizer, Patrick J., Jung, Rachel S., Stanhope, Kimber L., Havel, Peter J., Birrane, Gabriel, Meiyappan, Muthuraman, Gill, John E., Murakami, Masami, Miyashita, Kazuya, Nakajima, Katsuyuki, Ploug, Michael, Fong, Loren G., Young, Stephen G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: National Academy of Sciences 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442593/
https://www.ncbi.nlm.nih.gov/pubmed/30850549
http://dx.doi.org/10.1073/pnas.1900983116
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author Beigneux, Anne P.
Allan, Christopher M.
Sandoval, Norma P.
Cho, Geoffrey W.
Heizer, Patrick J.
Jung, Rachel S.
Stanhope, Kimber L.
Havel, Peter J.
Birrane, Gabriel
Meiyappan, Muthuraman
Gill, John E.
Murakami, Masami
Miyashita, Kazuya
Nakajima, Katsuyuki
Ploug, Michael
Fong, Loren G.
Young, Stephen G.
author_facet Beigneux, Anne P.
Allan, Christopher M.
Sandoval, Norma P.
Cho, Geoffrey W.
Heizer, Patrick J.
Jung, Rachel S.
Stanhope, Kimber L.
Havel, Peter J.
Birrane, Gabriel
Meiyappan, Muthuraman
Gill, John E.
Murakami, Masami
Miyashita, Kazuya
Nakajima, Katsuyuki
Ploug, Michael
Fong, Loren G.
Young, Stephen G.
author_sort Beigneux, Anne P.
collection PubMed
description Lipoprotein lipase (LPL), the enzyme that hydrolyzes triglycerides in plasma lipoproteins, is assumed to be active only as a homodimer. In support of this idea, several groups have reported that the size of LPL, as measured by density gradient ultracentrifugation, is ∼110 kDa, twice the size of LPL monomers (∼55 kDa). Of note, however, in those studies the LPL had been incubated with heparin, a polyanionic substance that binds and stabilizes LPL. Here we revisited the assumption that LPL is active only as a homodimer. When freshly secreted human LPL (or purified preparations of LPL) was subjected to density gradient ultracentrifugation (in the absence of heparin), LPL mass and activity peaks exhibited the size expected of monomers (near the 66-kDa albumin standard). GPIHBP1-bound LPL also exhibited the size expected for a monomer. In the presence of heparin, LPL size increased, overlapping with a 97.2-kDa standard. We also used density gradient ultracentrifugation to characterize the LPL within the high-salt and low-salt peaks from a heparin-Sepharose column. The catalytically active LPL within the high-salt peak exhibited the size of monomers, whereas most of the inactive LPL in the low-salt peak was at the bottom of the tube (in aggregates). Consistent with those findings, the LPL in the low-salt peak, but not that in the high-salt peak, was easily detectable with single mAb sandwich ELISAs, in which LPL is captured and detected with the same antibody. We conclude that catalytically active LPL can exist in a monomeric state.
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spelling pubmed-64425932019-04-05 Lipoprotein lipase is active as a monomer Beigneux, Anne P. Allan, Christopher M. Sandoval, Norma P. Cho, Geoffrey W. Heizer, Patrick J. Jung, Rachel S. Stanhope, Kimber L. Havel, Peter J. Birrane, Gabriel Meiyappan, Muthuraman Gill, John E. Murakami, Masami Miyashita, Kazuya Nakajima, Katsuyuki Ploug, Michael Fong, Loren G. Young, Stephen G. Proc Natl Acad Sci U S A PNAS Plus Lipoprotein lipase (LPL), the enzyme that hydrolyzes triglycerides in plasma lipoproteins, is assumed to be active only as a homodimer. In support of this idea, several groups have reported that the size of LPL, as measured by density gradient ultracentrifugation, is ∼110 kDa, twice the size of LPL monomers (∼55 kDa). Of note, however, in those studies the LPL had been incubated with heparin, a polyanionic substance that binds and stabilizes LPL. Here we revisited the assumption that LPL is active only as a homodimer. When freshly secreted human LPL (or purified preparations of LPL) was subjected to density gradient ultracentrifugation (in the absence of heparin), LPL mass and activity peaks exhibited the size expected of monomers (near the 66-kDa albumin standard). GPIHBP1-bound LPL also exhibited the size expected for a monomer. In the presence of heparin, LPL size increased, overlapping with a 97.2-kDa standard. We also used density gradient ultracentrifugation to characterize the LPL within the high-salt and low-salt peaks from a heparin-Sepharose column. The catalytically active LPL within the high-salt peak exhibited the size of monomers, whereas most of the inactive LPL in the low-salt peak was at the bottom of the tube (in aggregates). Consistent with those findings, the LPL in the low-salt peak, but not that in the high-salt peak, was easily detectable with single mAb sandwich ELISAs, in which LPL is captured and detected with the same antibody. We conclude that catalytically active LPL can exist in a monomeric state. National Academy of Sciences 2019-03-26 2019-03-08 /pmc/articles/PMC6442593/ /pubmed/30850549 http://dx.doi.org/10.1073/pnas.1900983116 Text en Copyright © 2019 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by-nc-nd/4.0/ This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND) (https://creativecommons.org/licenses/by-nc-nd/4.0/) .
spellingShingle PNAS Plus
Beigneux, Anne P.
Allan, Christopher M.
Sandoval, Norma P.
Cho, Geoffrey W.
Heizer, Patrick J.
Jung, Rachel S.
Stanhope, Kimber L.
Havel, Peter J.
Birrane, Gabriel
Meiyappan, Muthuraman
Gill, John E.
Murakami, Masami
Miyashita, Kazuya
Nakajima, Katsuyuki
Ploug, Michael
Fong, Loren G.
Young, Stephen G.
Lipoprotein lipase is active as a monomer
title Lipoprotein lipase is active as a monomer
title_full Lipoprotein lipase is active as a monomer
title_fullStr Lipoprotein lipase is active as a monomer
title_full_unstemmed Lipoprotein lipase is active as a monomer
title_short Lipoprotein lipase is active as a monomer
title_sort lipoprotein lipase is active as a monomer
topic PNAS Plus
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442593/
https://www.ncbi.nlm.nih.gov/pubmed/30850549
http://dx.doi.org/10.1073/pnas.1900983116
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