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Projeto de investigação
Investigating the mechanisms underpinning the interaction between autonomous immunity and intracellular S. aureus cell division and persistence.
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A Near InfraRed Emissive Chemosensor for Zn2+ and Phosphate Derivatives Based on a Di-(2-picolyl)amine-styrylflavylium Push-Pull Fluorophore
Publication . Gomes, Liliana J.; Carrilho, João P.; Pereira, Pedro M.; Moro, Artur J.; DQ - Departamento de Química; LAQV@REQUIMTE; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); MDPI - Multidisciplinary Digital Publishing Institute
A new Near InfraRed (NIR) fluorescent chemosensor for metal ions and anions is herein presented. The fluorophore is based on a styrylflavylium dye, a synthetic analogue of the natural anthocyanin family, with a di-(2-picolyl)amine (DPA) moiety as the metal chelating unit. The substitution pattern of the styrylflavylium core (with tertiary amines on positions 7 and 4′) shifts the optical properties of the dye towards the NIR region of the electronic spectra, due to a strong push-pull character over the π-conjugated system. The NIR chemosensor is highly sensitive to the presence of Zn2+, which induces a strong CHelation Enhanced Fluorescence (CHEF) effect upon binding to the DPA unit (2.7 fold increase). The strongest competing ion is Cu2+, with a complete fluorescence quenching, while other metals induce lower responses on the optical properties of the chemosensor. Subsequent anion screening of the Zn2+-chemosensor coordination compound has demonstrated a distinct selectivity towards adenosine 5′-triphosphate (ATP) and adenosine 5′-diphosphate (ADP), with high association constants (K ~ 106 M−1) and a strong CHEF effect (2.4 and 2.9 fold fluorescence increase for ATP and ADP, respectively). Intracellular studies with the Zn2+-complexed sensor showed strong luminescence in the cellular membrane of Gram– bacteria (E. coli) and mitochondrial membrane of mammalian cells (A659), which highlights its possible application for intracellular labelling.
Catalytic peptide-based coacervates for enhanced function through structural organization and substrate specificity
Publication . Reis, David Q.P.; Pereira, Sara; Ramos, Ana P.; Pereira, Pedro M.; Morgado, Leonor; Calvário, Joana; Henriques, Adriano O.; Serrano, Mónica; Pina, Ana S.; Instituto de Tecnologia Química e Biológica António Xavier (ITQB); UCIBIO - Applied Molecular Biosciences Unit; Faculdade de Ciências e Tecnologia (FCT); Nature Portfolio
Liquid-liquid phase separation (LLPS) in living cells provides innovative pathways for synthetic compartmentalized catalytic systems. While LLPS has been explored for enhancing enzyme catalysis, its potential application to catalytic peptides remains unexplored. Here, we demonstrate the use of coacervation, a key LLPS feature, to constrain the conformational flexibility of catalytic peptides, resulting in structured domains that enhance peptide catalysis. Using the flexible catalytic peptide P7 as a model, we induce reversible biomolecular coacervates with structured peptide domains proficient in hydrolyzing phosphate ester molecules and selectively sequestering phosphorylated proteins. Remarkably, these coacervate-based microreactors exhibit a 15,000-fold increase in catalytic efficiency compared to soluble peptides. Our findings highlight the potential of a single peptide to induce coacervate formation, selectively recruit substrates, and mediate catalysis, enabling a simple design for low-complexity, single peptide-based compartments with broad implications. Moreover, LLPS emerges as a fundamental mechanism in the evolution of chemical functions, effectively managing conformational heterogeneity in short peptides and providing valuable insights into the evolution of enzyme activity and catalysis in prebiotic chemistry.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
3599-PPCDT
Número da atribuição
PTDC/BIA-MIC/2422/2020