Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins
Autor(a) principal: | |
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Data de Publicação: | 2023 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10362/160974 |
Resumo: | Cancer cells overexpress tumour-associated O-glycans that interact with immune lectins leading to antitumour immune suppression. In this context, the rational design of molecules to block these aberrant interactions is an attractive strategy for the development of novel immunotherapies. Herein, the molecular recognition process of different tumour associated O-glycans (Tn, STn and TF), analogues, and mimetics, including those with trivalent presentation, by two immune lectins, Siglec-7 and MGL, was scrutinized. Ligand- and protein-based Nuclear Magnetic Resonance (NMR) binding methods assisted with molecular dynamics (MD) simulations were integrated to investigate this molecular recognition event. STn-Thr and STn-analogue similarly interact with the carbohydrate recognition domain (CRD) of Siglec-7, the Siglec-7d1, in the same binding site and mainly through the Neu5Ac moiety. The tail of STn-analogue does not interfere with the binding, being oriented towards the solvent, and therefore suitable for derivatization. Our NMR integrative approach (1H,15N-HSQC based titration, Tr-ROESY, STD-NMR) indicate that both Tn-analogue and STn-analogue bind to MGL-CRD and that the binding mode orientation of GalNAc towards MGL is similar in both structures. Additionally, the tail does not interact significantly with MGL-CRD, as determined in the Tr-ROESY and STD-NMR, and thus suitable for derivatization and dendrimerization since the tail is oriented towards the solvent, as revealed in the MD simulation. The binding of a trimer of Tn-antigen was also investigated. Our NMR data shows that Tn-Trimer competes with α-MeGalNAc for the same binding site in MGL-CRD in the competition titration assay. DOSY-NMR experiments suggests that Tn-Trimer can bind to more than one MGL-CRD simultaneously. With the obtained results it was not possible to infer if the affinity/avidity was improved with the multivalent presentation of Tn-antigen. Finally, 1H,15N-HSQC-based titration with a TF-mimetic and its corresponding trimer shows an increased binding affinity due to multivalent presentation, highlighting the importance of multivalency when creating mimetics. |
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Molecular recognition of tumour-associated O-glycans and mimetics by imune lectinsMolecular recognitionNMRMGLSiglec-7GlycomimeticscancerDomínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e TecnologiasCancer cells overexpress tumour-associated O-glycans that interact with immune lectins leading to antitumour immune suppression. In this context, the rational design of molecules to block these aberrant interactions is an attractive strategy for the development of novel immunotherapies. Herein, the molecular recognition process of different tumour associated O-glycans (Tn, STn and TF), analogues, and mimetics, including those with trivalent presentation, by two immune lectins, Siglec-7 and MGL, was scrutinized. Ligand- and protein-based Nuclear Magnetic Resonance (NMR) binding methods assisted with molecular dynamics (MD) simulations were integrated to investigate this molecular recognition event. STn-Thr and STn-analogue similarly interact with the carbohydrate recognition domain (CRD) of Siglec-7, the Siglec-7d1, in the same binding site and mainly through the Neu5Ac moiety. The tail of STn-analogue does not interfere with the binding, being oriented towards the solvent, and therefore suitable for derivatization. Our NMR integrative approach (1H,15N-HSQC based titration, Tr-ROESY, STD-NMR) indicate that both Tn-analogue and STn-analogue bind to MGL-CRD and that the binding mode orientation of GalNAc towards MGL is similar in both structures. Additionally, the tail does not interact significantly with MGL-CRD, as determined in the Tr-ROESY and STD-NMR, and thus suitable for derivatization and dendrimerization since the tail is oriented towards the solvent, as revealed in the MD simulation. The binding of a trimer of Tn-antigen was also investigated. Our NMR data shows that Tn-Trimer competes with α-MeGalNAc for the same binding site in MGL-CRD in the competition titration assay. DOSY-NMR experiments suggests that Tn-Trimer can bind to more than one MGL-CRD simultaneously. With the obtained results it was not possible to infer if the affinity/avidity was improved with the multivalent presentation of Tn-antigen. Finally, 1H,15N-HSQC-based titration with a TF-mimetic and its corresponding trimer shows an increased binding affinity due to multivalent presentation, highlighting the importance of multivalency when creating mimetics.As células do cancro sobreexpressam O-glicanos associados a tumores que interagem com lectinas presente em células do sistema imunitário levando a supressão da imunidade anti-tumoral. Neste contexto, o desenho racional de moléculas que bloqueiam estas interações é uma estratégia atrativa para desenvolver novas imunoterapias. Neste trabalho, o processo de reconhecimento molecular de diferentes O-glicanos associados a tumores (Tn, STn e TF), análogos e miméticos, incluindo apresentação trivalente, por duas lectinas, Siglec-7 e MGL, foi estudado por métodos de RMN e modelação molecular. O STn-Thr e STn-análogo interagem de forma semelhante com a Siglec-7d1, no mesmo local de ligação e maioritariamente através da unidade de Neu5Ac. O grupo funcional presente no STn-análogo colocado para futuras derivatizações não interfere com a ligação e está, de acordo com os dados obtidos, orientado para o solvente. A nossa abordagem integrativa de RMN (STD, Tr-ROESY e titulações baseadas em 1H,15N-HSQC) indica que ambos os análogos de Tn e STn ligam-se a MGL-CRD e que o modo de orientação da unidade GalNAc na MGL-CRD é semelhante para ambos os ligandos. Uma vez mais, as experiências de RMN sugerem que o grupo funcional presente nos análogos não interage significativamente com MGL-CRD e, portanto, é adequado para derivatização e dendrimerização. A ligação de um trímero do antigénio contendo Tn também foi explorada. O trímero contendo Tn compete com α-MeGalNAc para o local de ligação na MGL-CRD. As experiências de difusão sugerem que o trímero do Tn consegue ligar mais do que uma unidade de MGL-CRD simultaneamente. Finalmente, os dados de RMN dos complexos de MGL com um TF-mimético monovalente e trivalente, sugerem um aumento da afinidade devido à apresentação multivalente, e demonstram a importância da multivalência na construção de glicomiméticos.Marcelo, FilipaCoelho, HelenaRUNTravecedo, Maria Alejandra De Castro2023-11-082026-08-01T00:00:00Z2023-11-08T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/160974enginfo:eu-repo/semantics/embargoedAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-03-11T05:43:45Zoai:run.unl.pt:10362/160974Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:58:17.938318Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
title |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
spellingShingle |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins Travecedo, Maria Alejandra De Castro Molecular recognition NMR MGL Siglec-7 Glycomimetics cancer Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias |
title_short |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
title_full |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
title_fullStr |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
title_full_unstemmed |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
title_sort |
Molecular recognition of tumour-associated O-glycans and mimetics by imune lectins |
author |
Travecedo, Maria Alejandra De Castro |
author_facet |
Travecedo, Maria Alejandra De Castro |
author_role |
author |
dc.contributor.none.fl_str_mv |
Marcelo, Filipa Coelho, Helena RUN |
dc.contributor.author.fl_str_mv |
Travecedo, Maria Alejandra De Castro |
dc.subject.por.fl_str_mv |
Molecular recognition NMR MGL Siglec-7 Glycomimetics cancer Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias |
topic |
Molecular recognition NMR MGL Siglec-7 Glycomimetics cancer Domínio/Área Científica::Engenharia e Tecnologia::Outras Engenharias e Tecnologias |
description |
Cancer cells overexpress tumour-associated O-glycans that interact with immune lectins leading to antitumour immune suppression. In this context, the rational design of molecules to block these aberrant interactions is an attractive strategy for the development of novel immunotherapies. Herein, the molecular recognition process of different tumour associated O-glycans (Tn, STn and TF), analogues, and mimetics, including those with trivalent presentation, by two immune lectins, Siglec-7 and MGL, was scrutinized. Ligand- and protein-based Nuclear Magnetic Resonance (NMR) binding methods assisted with molecular dynamics (MD) simulations were integrated to investigate this molecular recognition event. STn-Thr and STn-analogue similarly interact with the carbohydrate recognition domain (CRD) of Siglec-7, the Siglec-7d1, in the same binding site and mainly through the Neu5Ac moiety. The tail of STn-analogue does not interfere with the binding, being oriented towards the solvent, and therefore suitable for derivatization. Our NMR integrative approach (1H,15N-HSQC based titration, Tr-ROESY, STD-NMR) indicate that both Tn-analogue and STn-analogue bind to MGL-CRD and that the binding mode orientation of GalNAc towards MGL is similar in both structures. Additionally, the tail does not interact significantly with MGL-CRD, as determined in the Tr-ROESY and STD-NMR, and thus suitable for derivatization and dendrimerization since the tail is oriented towards the solvent, as revealed in the MD simulation. The binding of a trimer of Tn-antigen was also investigated. Our NMR data shows that Tn-Trimer competes with α-MeGalNAc for the same binding site in MGL-CRD in the competition titration assay. DOSY-NMR experiments suggests that Tn-Trimer can bind to more than one MGL-CRD simultaneously. With the obtained results it was not possible to infer if the affinity/avidity was improved with the multivalent presentation of Tn-antigen. Finally, 1H,15N-HSQC-based titration with a TF-mimetic and its corresponding trimer shows an increased binding affinity due to multivalent presentation, highlighting the importance of multivalency when creating mimetics. |
publishDate |
2023 |
dc.date.none.fl_str_mv |
2023-11-08 2023-11-08T00:00:00Z 2026-08-01T00:00:00Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
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publishedVersion |
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http://hdl.handle.net/10362/160974 |
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eng |
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eng |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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