Atomistic description of the OCTN1 recognition mechanism via in silico methods.

The Organic Cation Transporter Novel 1 (OCTN1), also known as SLC22A4, is widely expressed in various human tissues, and involved in numerous physiological and pathological processes remains. It facilitates the transport of organic cations, zwitterions, with selectivity for positively charged solute...

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Main Authors: Omar Ben Mariem, Luca Palazzolo, Beatrice Torre, Yao Wei, Davide Bianchi, Uliano Guerrini, Tommaso Laurenzi, Simona Saporiti, Emma De Fabiani, Lorena Pochini, Cesare Indiveri, Ivano Eberini
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2024-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0304512&type=printable
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author Omar Ben Mariem
Luca Palazzolo
Beatrice Torre
Yao Wei
Davide Bianchi
Uliano Guerrini
Tommaso Laurenzi
Simona Saporiti
Emma De Fabiani
Lorena Pochini
Cesare Indiveri
Ivano Eberini
author_facet Omar Ben Mariem
Luca Palazzolo
Beatrice Torre
Yao Wei
Davide Bianchi
Uliano Guerrini
Tommaso Laurenzi
Simona Saporiti
Emma De Fabiani
Lorena Pochini
Cesare Indiveri
Ivano Eberini
author_sort Omar Ben Mariem
collection DOAJ
description The Organic Cation Transporter Novel 1 (OCTN1), also known as SLC22A4, is widely expressed in various human tissues, and involved in numerous physiological and pathological processes remains. It facilitates the transport of organic cations, zwitterions, with selectivity for positively charged solutes. Ergothioneine, an antioxidant compound, and acetylcholine (Ach) are among its substrates. Given the lack of experimentally solved structures of this protein, this study aimed at generating a reliable 3D model of OCTN1 to shed light on its substrate-binding preferences and the role of sodium in substrate recognition and transport. A chimeric model was built by grafting the large extracellular loop 1 (EL1) from an AlphaFold-generated model onto a homology model. Molecular dynamics simulations revealed domain-specific mobility, with EL1 exhibiting the highest impact on overall stability. Molecular docking simulations identified cytarabine and verapamil as highest affinity ligands, consistent with their known inhibitory effects on OCTN1. Furthermore, MM/GBSA analysis allowed the categorization of substrates into weak, good, and strong binders, with molecular weight strongly correlating with binding affinity to the recognition site. Key recognition residues, including Tyr211, Glu381, and Arg469, were identified through interaction analysis. Ach demonstrated a low interaction energy, supporting the hypothesis of its one-directional transport towards to outside of the membrane. Regarding the role of sodium, our model suggested the involvement of Glu381 in sodium binding. Molecular dynamics simulations of systems at increasing levels of Na+ concentrations revealed increased sodium occupancy around Glu381, supporting experimental data associating Na+ concentration to molecule transport. In conclusion, this study provides valuable insights into the 3D structure of OCTN1, its substrate-binding preferences, and the role of sodium in the recognition. These findings contribute to the understanding of OCTN1 involvement in various physiological and pathological processes and may have implications for drug development and disease management.
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spelling doaj-art-142668bdd25f42b9ae9ac75c8fd01b1e2024-12-13T05:31:51ZengPublic Library of Science (PLoS)PLoS ONE1932-62032024-01-01196e030451210.1371/journal.pone.0304512Atomistic description of the OCTN1 recognition mechanism via in silico methods.Omar Ben MariemLuca PalazzoloBeatrice TorreYao WeiDavide BianchiUliano GuerriniTommaso LaurenziSimona SaporitiEmma De FabianiLorena PochiniCesare IndiveriIvano EberiniThe Organic Cation Transporter Novel 1 (OCTN1), also known as SLC22A4, is widely expressed in various human tissues, and involved in numerous physiological and pathological processes remains. It facilitates the transport of organic cations, zwitterions, with selectivity for positively charged solutes. Ergothioneine, an antioxidant compound, and acetylcholine (Ach) are among its substrates. Given the lack of experimentally solved structures of this protein, this study aimed at generating a reliable 3D model of OCTN1 to shed light on its substrate-binding preferences and the role of sodium in substrate recognition and transport. A chimeric model was built by grafting the large extracellular loop 1 (EL1) from an AlphaFold-generated model onto a homology model. Molecular dynamics simulations revealed domain-specific mobility, with EL1 exhibiting the highest impact on overall stability. Molecular docking simulations identified cytarabine and verapamil as highest affinity ligands, consistent with their known inhibitory effects on OCTN1. Furthermore, MM/GBSA analysis allowed the categorization of substrates into weak, good, and strong binders, with molecular weight strongly correlating with binding affinity to the recognition site. Key recognition residues, including Tyr211, Glu381, and Arg469, were identified through interaction analysis. Ach demonstrated a low interaction energy, supporting the hypothesis of its one-directional transport towards to outside of the membrane. Regarding the role of sodium, our model suggested the involvement of Glu381 in sodium binding. Molecular dynamics simulations of systems at increasing levels of Na+ concentrations revealed increased sodium occupancy around Glu381, supporting experimental data associating Na+ concentration to molecule transport. In conclusion, this study provides valuable insights into the 3D structure of OCTN1, its substrate-binding preferences, and the role of sodium in the recognition. These findings contribute to the understanding of OCTN1 involvement in various physiological and pathological processes and may have implications for drug development and disease management.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0304512&type=printable
spellingShingle Omar Ben Mariem
Luca Palazzolo
Beatrice Torre
Yao Wei
Davide Bianchi
Uliano Guerrini
Tommaso Laurenzi
Simona Saporiti
Emma De Fabiani
Lorena Pochini
Cesare Indiveri
Ivano Eberini
Atomistic description of the OCTN1 recognition mechanism via in silico methods.
PLoS ONE
title Atomistic description of the OCTN1 recognition mechanism via in silico methods.
title_full Atomistic description of the OCTN1 recognition mechanism via in silico methods.
title_fullStr Atomistic description of the OCTN1 recognition mechanism via in silico methods.
title_full_unstemmed Atomistic description of the OCTN1 recognition mechanism via in silico methods.
title_short Atomistic description of the OCTN1 recognition mechanism via in silico methods.
title_sort atomistic description of the octn1 recognition mechanism via in silico methods
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0304512&type=printable
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