A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling
Abstract The enzyme cholesterol lecithin acyl transferase (LCAT) shares the Ser/Asp‐Glu/His triad with lipases, esterases and proteases, but the low level of sequence homology between LCAT and these enzymes did not allow for the LCAT fold to be identified yet. We, therefore, relied upon structural h...
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crwiley:10.1002/pro.5560070307 2024-06-02T07:58:04+00:00 A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling Peelman, F. Vinaimont, N. Vanloo, B. Labeur, C. Rosseneu, M. Verhee, A. Verschelde, J‐L. Vanderckove, J. Tavernier, J. Seguret‐Mace, S. Duverger, N. Hutchinson, G. Quiochoat Baylor College of Medicine Lawrence Livermore National Laboratory NIH 1998 http://dx.doi.org/10.1002/pro.5560070307 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fpro.5560070307 https://onlinelibrary.wiley.com/doi/pdf/10.1002/pro.5560070307 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Protein Science volume 7, issue 3, page 587-599 ISSN 0961-8368 1469-896X journal-article 1998 crwiley https://doi.org/10.1002/pro.5560070307 2024-05-03T11:06:22Z Abstract The enzyme cholesterol lecithin acyl transferase (LCAT) shares the Ser/Asp‐Glu/His triad with lipases, esterases and proteases, but the low level of sequence homology between LCAT and these enzymes did not allow for the LCAT fold to be identified yet. We, therefore, relied upon structural homology calculations using threading methods based on alignment of the sequence against a library of solved three‐dimensional protein structures, for prediction of the LCAT fold. We propose that LCAT, like lipases, belongs to the α/β hydrolase fold family, and that the central domain of LCAT consists of seven conserved parallel beta‐strands connected by four α‐helices and separated by loops. We used the conserved features of this protein fold for the prediction of functional domains in LCAT, and carried out site‐directed mutagenesis for the localization of the active site residues. The wild‐type enzyme and mutants were expressed in Cos‐1 cells. LCAT mass was measured by ELISA, and enzymatic activity was measured on recombinant HDL, on LDL and on a monomelic substrate. We identified D345 and H377 as the catalytic residues of LCAT, together with F103 and L182 as the oxyanion hole residues. In analogy with lipases, we further propose that a potential “lid” domain at residues 50‐74 of LCAT might be involved in the enzyme‐substrate interaction. Molecular modeling of human LCAT was carried out using human pancreatic and Candida antarctica lipases as templates. The three‐dimensional model proposed here is compatible with the position of natural mutants for either LCAT deficiency or Fish‐eye disease. It enables moreover prediction of the LCAT domains involved in the interaction with the phospholipid and cholesterol substrates. Article in Journal/Newspaper Antarc* Antarctica Wiley Online Library Protein Science 7 3 587 599 |
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Open Polar |
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Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract The enzyme cholesterol lecithin acyl transferase (LCAT) shares the Ser/Asp‐Glu/His triad with lipases, esterases and proteases, but the low level of sequence homology between LCAT and these enzymes did not allow for the LCAT fold to be identified yet. We, therefore, relied upon structural homology calculations using threading methods based on alignment of the sequence against a library of solved three‐dimensional protein structures, for prediction of the LCAT fold. We propose that LCAT, like lipases, belongs to the α/β hydrolase fold family, and that the central domain of LCAT consists of seven conserved parallel beta‐strands connected by four α‐helices and separated by loops. We used the conserved features of this protein fold for the prediction of functional domains in LCAT, and carried out site‐directed mutagenesis for the localization of the active site residues. The wild‐type enzyme and mutants were expressed in Cos‐1 cells. LCAT mass was measured by ELISA, and enzymatic activity was measured on recombinant HDL, on LDL and on a monomelic substrate. We identified D345 and H377 as the catalytic residues of LCAT, together with F103 and L182 as the oxyanion hole residues. In analogy with lipases, we further propose that a potential “lid” domain at residues 50‐74 of LCAT might be involved in the enzyme‐substrate interaction. Molecular modeling of human LCAT was carried out using human pancreatic and Candida antarctica lipases as templates. The three‐dimensional model proposed here is compatible with the position of natural mutants for either LCAT deficiency or Fish‐eye disease. It enables moreover prediction of the LCAT domains involved in the interaction with the phospholipid and cholesterol substrates. |
author2 |
Quiochoat Baylor College of Medicine Lawrence Livermore National Laboratory NIH |
format |
Article in Journal/Newspaper |
author |
Peelman, F. Vinaimont, N. Vanloo, B. Labeur, C. Rosseneu, M. Verhee, A. Verschelde, J‐L. Vanderckove, J. Tavernier, J. Seguret‐Mace, S. Duverger, N. Hutchinson, G. |
spellingShingle |
Peelman, F. Vinaimont, N. Vanloo, B. Labeur, C. Rosseneu, M. Verhee, A. Verschelde, J‐L. Vanderckove, J. Tavernier, J. Seguret‐Mace, S. Duverger, N. Hutchinson, G. A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
author_facet |
Peelman, F. Vinaimont, N. Vanloo, B. Labeur, C. Rosseneu, M. Verhee, A. Verschelde, J‐L. Vanderckove, J. Tavernier, J. Seguret‐Mace, S. Duverger, N. Hutchinson, G. |
author_sort |
Peelman, F. |
title |
A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
title_short |
A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
title_full |
A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
title_fullStr |
A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
title_full_unstemmed |
A proposed architecture for lecithin cholesterol acyl transferase (LCAT): Identification of the catalytic triad and molecular modeling |
title_sort |
proposed architecture for lecithin cholesterol acyl transferase (lcat): identification of the catalytic triad and molecular modeling |
publisher |
Wiley |
publishDate |
1998 |
url |
http://dx.doi.org/10.1002/pro.5560070307 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fpro.5560070307 https://onlinelibrary.wiley.com/doi/pdf/10.1002/pro.5560070307 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Protein Science volume 7, issue 3, page 587-599 ISSN 0961-8368 1469-896X |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/pro.5560070307 |
container_title |
Protein Science |
container_volume |
7 |
container_issue |
3 |
container_start_page |
587 |
op_container_end_page |
599 |
_version_ |
1800741330813452288 |