title: Structural studies of the protein endostatin in fusion with BAX BH3 death domain, a hybrid that presents enhanced antitumoral activity.
abstract: Endostatin (ES) is an antiangiogenic protein that exhibits antitumor activity in animal models. However, the activity observed in animals was not observed in human clinical trials. ES-BAX is a fusion protein composed of two functional domains: ES, which presents specificity and is internalized by activated endothelial cells and the proapoptotic BH3 domain of the protein BAX, a peptide inductor of cellular death when internalized. We have previously shown (Chura-Chambi et al., Cell Death Dis, 5, e1371, 2014) that ES-BAX presents improved antitumor activity in relation to wild-type ES. Secondary and tertiary structures of ES-BAX are similar to ES, as indicated by homology-modeling studies and molecular dynamics simulations. Tryptophan intrinsic fluorescence and circular dichroism spectroscopy corroborate these data.15N HSQC NMR indicates that ES-BAX is structured, but some ES residues have suffered chemical shift perturbations, suggesting that the BH3 peptide interacts with some parts of the ES protein. ES and ES-BAX present similar stability to thermal denaturation. The production of stable hybrid proteins can be a new approach to the development of therapeutic agents presenting specificity for tumoral endothelium and improved antitumor effect.
authors.affiliation: Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, São Paulo, Brazil.
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Chura-Chambi
authors.affiliation: Departamento de Imunologia Clínica e Alergia da Faculdade de Medicina da USP, São Paulo, Brazil.
authors.forename: Helen Andrade
authors.initials: HA
authors.lastname: Arcuri
authors.affiliation: Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, São Paulo, Brazil.
authors.forename: Felipe
authors.initials: F
authors.lastname: Lino
authors.affiliation: Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, São Paulo, Brazil.
authors.forename: Natan
authors.initials: N
authors.lastname: Versati
authors.affiliation: Centro de Estudos de Insetos Sociais, Instituto de Biociências de Rio Claro, UNESP, Rio Claro, São Paulo, Brazil.
authors.forename: Mario Sergio
authors.initials: MS
authors.lastname: Palma
authors.affiliation: Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Denize C
authors.initials: DC
authors.lastname: Favaro
authors.affiliation: Centro de Biotecnologia, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP, São Paulo, Brazil.
authors.forename: Ligia
authors.initials: L
authors.lastname: Morganti
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D043169:Endostatins / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D000072417:Protein Domains; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics; D051028:bcl-2-Associated X Protein / Q000737:chemistry* / Q000235:genetics
chemical_list: D000970:Antineoplastic Agents; C494826:BAX protein, human; D043169:Endostatins; D011993:Recombinant Fusion Proteins; D051028:bcl-2-Associated X Protein
keywords: BAX; BH3 domain; angiogenesis; apoptosis; circular dichroism; endostatin; molecular modeling