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Projeto de investigação
RedoxMaze – Understanding bacterial extracellular electron transfer for sustainable bio-based solutions
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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.
Tethered heme domains in a triheme cytochrome allow for increased electron transport distances
Publication . Nash, Benjamin W.; Fernandes, Tomás M.; Burton, Joshua A.J.; Morgado, Leonor; van Wonderen, Jessica H.; Svistunenko, Dimitri A.; Edwards, Marcus J.; Salgueiro, Carlos A.; Butt, Julea N.; Clarke, Thomas A.; UCIBIO - Applied Molecular Biosciences Unit; DQ - Departamento de Química; Faculdade de Ciências e Tecnologia (FCT); Wiley-Blackwell
Decades of research describe myriad redox enzymes that contain cofactors arranged in tightly packed chains facilitating rapid and controlled intra-protein electron transfer. Many such enzymes participate in extracellular electron transfer (EET), a process which allows microorganisms to conserve energy in anoxic environments by exploiting mineral oxides and other extracellular substrates as terminal electron acceptors. In this work, we describe the properties of the triheme cytochrome PgcA from Geobacter sulfurreducens. PgcA has been shown to play an important role in EET but is unusual in containing three CXXCH heme binding motifs that are separated by repeated (PT)x motifs, suggested to enhance binding to mineral surfaces. Using a combination of structural, electrochemical, and biophysical techniques, we experimentally demonstrate that PgcA adopts numerous conformations stretching as far as 180 Å between the ends of domains I and III, without a tightly packed cofactor chain. Furthermore, we demonstrate a distinct role for its domain III as a mineral reductase that is recharged by domains I and II. These findings show PgcA to be the first of a new class of electron transfer proteins, with redox centers separated by some nanometers but tethered together by flexible linkers, facilitating electron transfer through a tethered diffusion mechanism rather than a fixed, closely packed electron transfer chain.
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Fundação para a Ciência e a Tecnologia
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CEEC IND4ed
Número da atribuição
2021.02185.CEECIND/CP1657/CT0008