ABSTRACT
BACKGROUND: Human infectious diseases caused by bacteria are a worldwide health problem due to the increased resistance of these microorganisms to conventional antibiotics. For this reason, the identification of novel molecular targets and the discovery of new antibacterial compounds are urgently required. Metalo-aminopeptidases are promising targets in bacterial infections. They participate in crucial processes for bacterial growth and pathogenesis, such as protein and peptide degradation to supply amino acids, protein processing, access to host tissues, cysteine supply for redox control, transcriptional regulation, site-specific DNA recombination, and hydrogen sulfide production. Although several of these enzymes are not essential, they are required for virulence and maximal growth in conditions of nutrient limitation and high temperatures. OBJECTIVE: In this review, we describe the structural, functional, and kinetic properties of some examples of bacterial metalo-aminopeptidases, in the context of their use as antibacterial targets. In addition, we present some inhibitors reported for these enzymes. CONCLUSION: It is necessary to conduct a meticulous work to validate these peptidases as good/bad targets and to identify inhibitors with potential therapeutic use.
Subject(s)
Communicable Diseases , Hydrogen Sulfide , Aminopeptidases , Anti-Bacterial Agents/pharmacology , Bacteria/metabolism , Cysteine , DNA , Humans , Peptide Hydrolases , PeptidesABSTRACT
Contamination by heavy metal ions, particularly in water resources, is a severe environmental problem. In this study, the interaction of metal ions, namely, Cadmium Cd(II), Mercury Hg(II), and Lead Pb(II), on lignin matrices was investigated based on theoretical calculations. Binding energy (ΔEBind) values proved that the Pb(II) interacted better with lignin matrices than Cd(II) or Hg(II), having energy values between -8.4 kcal mol-1 to -20.2 kcal mol-1. The Gibbs energy (ΔG) and enthalpy (ΔH) values for Pb(II) were <0, indicating that the process was spontaneous and released heat. However, the lignin matrices studied in this work did not interact efficiently with Cd(II) and Hg(II) ions because almost all ΔEBind, ΔG, and ΔH values were positive. The bond length of the interaction proved that the Pb ions yielded the smallest values, ratifying the values for the interaction energy. Analyses based on the quantum theory of atoms in molecules showed that the interactions between Pb(II) and the matrices were partially covalent, whereas the interactions of Cd(II) and Hg(II) were predominantly electrostatic, justifying the positive values of ΔEBind, ΔG, and ΔH. The natural bond orbital results showed that the ligand orbitals of the matrix interacted with the lone pair antibonding orbital (LP*) of the metal ions. The theoretical results of the study show the possibility of applying lignin to remove heavy metal ions, especially Pb, and providing information for research related to wastewater treatment.
Subject(s)
Mercury , Metals, Heavy , Adsorption , Cadmium , Ions , Kinetics , Lead , LigninABSTRACT
The decisive role of metallic cations in the formation of supramolecular clusters involving lignin, cellulose, and hemi-cellulose and its relationship to energy losses in ruminants associated with fibrous feed resources is still not well understood. Indeed, interactions between lignin, cellulose and metallic cations generate highly stable clusters that significantly decrease the capability of cellulase to break bonds between sugar units in order to facilitate the absorption of a great quantity of cellulose, which is ingested by ruminants as forage. Furthermore, several metallic cations cannot be absorbed as a consequence of the formation of coordinated ligations with the oxygen atoms of the lignocellulosic cluster. The loss of lignocellulose-metal clusters by ruminants is responsible for a substantial waste of nutrients, which is a significant problem in animal science. Moreover, the chemical structure of these relevant supramolecular systems is poorly understood. In the present review, we discussed this topic in detail in reference to relevant literature from the chemical and animal sciences in order to analyze the perspectives associated with the improvement of nutritional absorption from feed resources by ruminants.
O papel decisivo de cátions metálicos na formação de cluster supramoleculares envolvendo lignina, celulose e hemi-celulose and sua relação a perdas energéticas em ruminantes associadas com fontes de alimentação fibrosas não é ainda bem compreendida. De fato, interações entre lignina, celulose e cátions metálicos geram clusters altamente estáveis diminuem significativamente a capacidade da celulase quebrar ligações entre unidades sacarídicas com o objetivo de facilitar a absorção de uma grande quantidade de celulose, a qual é ingerida por ruminantes na forma de forragem. Além disso, diversos cátions metálicos não podem ser absorvidos como uma conseqüência da formação de ligações coordenadas com os átomos de oxigênio do cluster lignocelulósico. A perda de clusters lignocelulósico-metálicos por ruminantes é responsável por um substancial desperdício de nutrientes, o que é um problema significativo em zootecnia. Ademais, a estrutura química destes relevantes sistemas supramoleculares é pobremente compreendida. No presente artigo, nós discutimos esse tópico em detalhes, em concordância com relevante literatura química e zootécnica, objetivando analisar as perspectivas relacionadas com a melhoria com a absorção nutricional a partir de fontes alimentares por ruminantes.
Subject(s)
Animals , Digestion , Dietary Fiber , Dietary Fiber/administration & dosage , Dietary Fiber/analysis , Ruminants/metabolism , CelluloseABSTRACT
The decisive role of metallic cations in the formation of supramolecular clusters involving lignin, cellulose, and hemi-cellulose and its relationship to energy losses in ruminants associated with fibrous feed resources is still not well understood. Indeed, interactions between lignin, cellulose and metallic cations generate highly stable clusters that significantly decrease the capability of cellulase to break bonds between sugar units in order to facilitate the absorption of a great quantity of cellulose, which is ingested by ruminants as forage. Furthermore, several metallic cations cannot be absorbed as a consequence of the formation of coordinated ligations with the oxygen atoms of the lignocellulosic cluster. The loss of lignocellulose-metal clusters by ruminants is responsible for a substantial waste of nutrients, which is a significant problem in animal science. Moreover, the chemical structure of these relevant supramolecular systems is poorly understood. In the present review, we discussed this topic in detail in reference to relevant literature from the chemical and animal sciences in order to analyze the perspectives associated with the improvement of nutritional absorption from feed resources by ruminants.(AU)
O papel decisivo de cátions metálicos na formação de cluster supramoleculares envolvendo lignina, celulose e hemi-celulose and sua relação a perdas energéticas em ruminantes associadas com fontes de alimentação fibrosas não é ainda bem compreendida. De fato, interações entre lignina, celulose e cátions metálicos geram clusters altamente estáveis diminuem significativamente a capacidade da celulase quebrar ligações entre unidades sacarídicas com o objetivo de facilitar a absorção de uma grande quantidade de celulose, a qual é ingerida por ruminantes na forma de forragem. Além disso, diversos cátions metálicos não podem ser absorvidos como uma conseqüência da formação de ligações coordenadas com os átomos de oxigênio do cluster lignocelulósico. A perda de clusters lignocelulósico-metálicos por ruminantes é responsável por um substancial desperdício de nutrientes, o que é um problema significativo em zootecnia. Ademais, a estrutura química destes relevantes sistemas supramoleculares é pobremente compreendida. No presente artigo, nós discutimos esse tópico em detalhes, em concordância com relevante literatura química e zootécnica, objetivando analisar as perspectivas relacionadas com a melhoria com a absorção nutricional a partir de fontes alimentares por ruminantes.(AU)
Subject(s)
Animals , Ruminants/metabolism , Digestion , Dietary Fiber/administration & dosage , Dietary Fiber/analysis , Dietary Fiber , CelluloseABSTRACT
The decisive role of metallic cations in the formation of supramolecular clusters involving lignin, cellulose, and hemi-cellulose and its relationship to energy losses in ruminants associated with fibrous feed resources is still not well understood. Indeed, interactions between lignin, cellulose and metallic cations generate highly stable clusters that significantly decrease the capability of cellulase to break bonds between sugar units in order to facilitate the absorption of a great quantity of cellulose, which is ingested by ruminants as forage. Furthermore, several metallic cations cannot be absorbed as a consequence of the formation of coordinated ligations with the oxygen atoms of the lignocellulosic cluster. The loss of lignocellulose-metal clusters by ruminants is responsible for a substantial waste of nutrients, which is a significant problem in animal science. Moreover, the chemical structure of these relevant supramolecular systems is poorly understood. In the present review, we discussed this topic in detail in reference to relevant literature from the chemical and animal sciences in order to analyze the perspectives associated with the improvement of nutritional absorption from feed resources by ruminants.
O papel decisivo de cátions metálicos na formação de cluster supramoleculares envolvendo lignina, celulose e hemi-celulose and sua relação a perdas energéticas em ruminantes associadas com fontes de alimentação fibrosas não é ainda bem compreendida. De fato, interações entre lignina, celulose e cátions metálicos geram clusters altamente estáveis diminuem significativamente a capacidade da celulase quebrar ligações entre unidades sacarídicas com o objetivo de facilitar a absorção de uma grande quantidade de celulose, a qual é ingerida por ruminantes na forma de forragem. Além disso, diversos cátions metálicos não podem ser absorvidos como uma conseqüência da formação de ligações coordenadas com os átomos de oxigênio do cluster lignocelulósico. A perda de clusters lignocelulósico-metálicos por ruminantes é responsável por um substancial desperdício de nutrientes, o que é um problema significativo em zootecnia. Ademais, a estrutura química destes relevantes sistemas supramoleculares é pobremente compreendida. No presente artigo, nós discutimos esse tópico em detalhes, em concordância com relevante literatura química e zootécnica, objetivando analisar as perspectivas relacionadas com a melhoria com a absorção nutricional a partir de fontes alimentares por ruminantes.