RESUMO
Faced with the emergence of multiresistant microorganisms that affect human health, microbial agents have become a serious global threat, affecting human health and plant crops. Antimicrobial peptides have attracted significant attention in research for the development of new microbial control agents. This work's goal was the structural characterization and analysis of antifungal activity of chitin-binding peptides from Capsicum baccatum and Capsicum frutescens seeds on the growth of Candida and Fusarium species. Proteins were initially submitted to extraction in phosphate buffer pH 5.4 and subjected to chitin column chromatography. Posteriorly, two fractions were obtained for each species, Cb-F1 and Cf-F1 and Cb-F2 and Cf-F2, respectively. The Cb-F1 (C. baccatum) and Cf-F1 (C. frutescens) fractions did not bind to the chitin column. The electrophoresis results obtained after chromatography showed two major protein bands between 3.4 and 14.2 kDa for Cb-F2. For Cf-F2, three major bands were identified between 6.5 and 14.2 kDa. One band from each species was subjected to mass spectrometry, and both bands showed similarity to nonspecific lipid transfer protein. Candida albicans and Candida tropicalis had their growth inhibited by Cb-F2. Cf-F2 inhibited the development of C. albicans but did not inhibit the growth of C. tropicalis. Both fractions were unable to inhibit the growth of Fusarium species. The toxicity of the fractions was tested in vivo on Galleria mellonella larvae, and both showed a low toxicity rate at high concentrations. As a result, the fractions have enormous promise for the creation of novel antifungal compounds.
Assuntos
Antifúngicos , Candida , Quitina , Fusarium , Simulação de Acoplamento Molecular , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Quitina/química , Quitina/metabolismo , Fusarium/efeitos dos fármacos , Candida/efeitos dos fármacos , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Animais , Capsicum/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Proteínas de Plantas/farmacologia , Testes de Sensibilidade Microbiana , Ligação Proteica , Conformação ProteicaRESUMO
Chitin is a polymer of N-acetylglucosamine and an essential component of the fungal cell wall. Chitosan is the deacetylated form of chitin and is also important for maintaining the integrity of this structure. Both polysaccharides are widely distributed in nature and have been shown to have a variety of applications in biomedicine, including their potential in immune sensing and as potential antifungal agents. In addition, chitin has been reported to play an important role in the pathogen-host interaction, involving innate and adaptive immune responses. This paper will explore the role of chitin and chitosan when incorporated into nanobiocomposites to improve their efficacy in detecting fungi of medical interest and inhibiting their growth. Potential applications in diagnostic and therapeutic medicine will be discussed, highlighting their promise in the development of more sensitive and effective tools for the early diagnosis of fungal infections. This review aims to highlight the importance of the convergence of nanotechnology and biology in addressing public health challenges.
Assuntos
Antifúngicos , Quitina , Quitosana , Fungos , Quitina/química , Quitina/farmacologia , Quitosana/química , Quitosana/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Fungos/efeitos dos fármacos , Fungos/química , Humanos , Nanocompostos/química , Micoses/imunologia , Micoses/tratamento farmacológico , Micoses/diagnósticoRESUMO
Chitosan is a cationic polysaccharide derived from chitin deacetylation. This polysaccharide and its oligosaccharides have many biological activities and can be used in several fields due to their favorable characteristics, such as biodegradability, biocompatibility, and nontoxicity. This review aims to explore the antifungal potential of chitosan and chitooligosaccharides along with the conditions used for the activity and mechanisms of action they use to kill fungal cells. The sources, chemical properties, and applications of chitosan and chitooligosaccharides are discussed in this review. It also addresses the threat fungi pose to human health and crop production and how these saccharides have proven to be effective against these microorganisms. The cellular processes triggered by chitosan and chitooligosaccharides in fungal cells, and prospects for their use as potential antifungal agents are also examined.
Assuntos
Antifúngicos , Quitosana , Fungos , Oligossacarídeos , Quitosana/química , Quitosana/farmacologia , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/síntese química , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Fungos/efeitos dos fármacos , Humanos , Quitina/química , Quitina/farmacologia , Quitina/análogos & derivados , Testes de Sensibilidade MicrobianaRESUMO
This work aimed to obtain and characterize chitin and chitosan extracted from the rearing residues of Tenebrio molitor, Zophobas morio, and Blaptica dubia insects in different growth stages in the same rearing cycles chitin and chitosan yielded 11.21 %-20.89 % and 6.26 %-7.07 %, respectively. The deacetylation degrees of chitosan ranged from 75.75 %-89.21 %, and the solubilities from 69.88 %-94.39 %. Infrared spectroscopy corroborated the acquisition of chitin and chitosan and can be used as a semi-quantitative technique for determining the degree of chitosan deacetylation. The X-ray diffraction profiles revealed the presence of α-chitin, and the relative crystalline indices ranged from 65.9 %-89.2 %. Typical TG profiles with two thermal events are observed for chitin and chitosan samples with different residue contents from the extraction procedure. The chitosan solutions exhibited pseudoplastic behavior, with apparent viscosities ranging from 195.96 to 249.86 mPa.s. The characterization results of the biopolymers extracted from insect residues were similar to those obtained from conventional sources. The growth stage influenced the chitin yield and crystallinity index. The results of this study reinforce the feasibility of using alternative sources of chitin and chitosan, providing the use of waste from insect farms and contributing to sustainability and a circular economy.
Assuntos
Quitosana , Besouros , Animais , Quitosana/química , Quitina/química , Insetos , Besouros/química , Difração de Raios XRESUMO
Chitin is a biopolymer profusely present in nature and of pivotal importance as a structural component in cells. It is degraded by chitinases, enzymes naturally produced by different organisms. Chitinases are proteins enrolled in many cellular mechanisms, including the remodeling process of the fungal cell wall, the cell growth process, the autolysis of filamentous fungi, and cell separation of yeasts, among others. These enzymes also have properties with different biotechnological applications. They are used to produce polymers, for biological control, biofilm formation, and as antitumor and anti-inflammatory target molecules. Chitinases are classified into different glycoside hydrolase (GH) families and are widespread in microorganisms, including viruses. Among them, the GH18 family is highly predominant in the viral genomes, being present and active enzymes in baculoviruses and nucleocytoplasmic large DNA viruses (NCLDV), especially chloroviruses from the Phycodnaviridae family. These viral enzymes contain one or more GH domains and seem to be involved during the viral replication cycle. Curiously, only a few DNA viruses have these enzymes, and studying their properties could be a key feature for biological and biotechnological novelties. Here, we provide an overview of viral chitinases and their probable function in viral infection, showing evidence of at least two distinct origins for these enzymes. Finally, we discuss how these enzymes can be applied as biotechnological tools and what one can expect for the coming years on these GHs.
Assuntos
Quitinases , Humanos , Quitinases/química , Quitinases/genética , Quitinases/metabolismo , Proteínas , Quitina/química , Quitina/metabolismo , Biotecnologia , FungosRESUMO
Chitinases are enzymes that degrade chitin, a polysaccharide found in the exoskeleton of insects, fungi, yeast, and internal structures of other vertebrates. Although chitinases isolated from bacteria, fungi and plants have been reported to have antifungal or insecticide activities, chitinases from insects with these activities have been seldomly reported. In this study, a leaf-cutting ant Atta sexdens DNA fragment containing 1623 base pairs was amplified and cloned into a vector to express the protein (AsChtII-C4B1) in Pichia pastoris. AsChtII-C4B1, which contains one catalytic domain and one carbohydrate-binding module (CBM), was secreted to the extracellular medium and purified by ammonium sulfate precipitation followed by nickel column chromatography. AsChtII-C4B1 showed maximum activity at pH 5.0 and 55 °C when tested against colloidal chitin substrate and maintained >60% of its maximal activity in different temperatures during 48 h. AsChtII-C4B1 decreased the survival of Spodoptera frugiperda larvae fed with an artificial diet that contained AsChtII-C4B1. Our results have indicated that AsChtII-C4B1 has a higher effect on larva-pupa than larva-larva molts. AsChtII-C4B1 activity targets more specifically the growth of filamentous fungus than yeast. This work describes, for the first time, the obtaining a recombinant chitinase from ants and the characterization of its insecticidal and antifungal activities.
Assuntos
Formigas , Quitinases , Animais , Antifúngicos/química , Formigas/enzimologia , Formigas/genética , Formigas/metabolismo , Quitina/química , Quitinases/química , Quitinases/genética , Quitinases/farmacologia , Clonagem Molecular , Fungos/metabolismo , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Catálise , Domínio CatalíticoRESUMO
An experimental study on the evolution of the physicochemical, thermal and nanostructural properties of chitosan samples obtained from squid pens as the deacetylation treatment proceeds is presented. To this aim, potentiometric titration, capillary viscosimetry, infrared spectroscopy, differential scanning calorimetry and positron annihilation lifetime spectroscopy were used. The results obtained are discussed in terms of the influence of the deacetylation time on the deacetylation degree, average molecular weight, thermal parameters and average free nanohole size of the different samples. A way of preparing chitosan matrices with tailored nanostructural characteristics for specific applications through the deacetylation process is explored.
Assuntos
Quitosana , Animais , Varredura Diferencial de Calorimetria , Quitina/química , Quitosana/química , Decapodiformes/química , Peso Molecular , PósRESUMO
BACKGROUND: Chitinases are plant defense-related proteins with a high biotechnological potential to be applied in agriculture. OBJECTIVES: This study aimed to purify a chitinase from the latex of Ficus benjamina. METHODS: An antifungal class I chitinase, named FbLx-Chi-1, was purified from the latex of Ficus benjamina after precipitation with 30-60% ammonium sulfate and affinity chromatography on a chitin column and antifungal potential assay against phytopathogenic fungi important to agriculture. RESULTS: FbLx-Chi-1 has 30 kDa molecular mass, as estimated by SDS-PAGE and the optimal pH and temperature for full chitinolytic activity were 5.5 and 60ºC, respectively. FbLx-Chi-1 is a high pH-, ion-tolerant and thermostable protein. Importantly, FbLx-Chi-1 hindered the growth of the phytopathogenic fungi Colletotrichum gloeosporioides, Fusarium pallidoroseum, and Fusarium oxysporum. The action mode of FbLx-Chi-1 to hamper F. pallidoroseum growth seems to be correlated with alterations in the morphology of the hyphal cell wall, increased plasma membrane permeability, and overproduction of reactive oxygen species. CONCLUSION: These findings highlight the biotechnological potential of FbLx-Chi-1 to control important phytopathogenic fungi in agriculture. In addition, FbLx-Chi-1 could be further explored to be used in industrial processes such as the large-scale environmentally friendly enzymatic hydrolysis of chitin to produce its monomer N-acetyl-ß-D-glucosamine, which is employed for bioethanol production, in cosmetics, in medicine, and for other multiple applications.
Assuntos
Quitinases , Ficus , Antifúngicos/farmacologia , Antifúngicos/química , Látex , Ficus/metabolismo , Espécies Reativas de Oxigênio , Quitinases/farmacologia , Quitinases/química , Quitinases/metabolismo , Quitina/farmacologia , Quitina/química , Parede Celular/metabolismo , Membrana Celular/metabolismoRESUMO
BACKGROUND AND OBJECTIVE: Residues from shrimp farming have a great potential for sugar production and the production of derivatives for the low-carbon chemical industry. Obtainment of bioactives from chitosan has been extensively investigated using different methodologies. The purpose of this work was to study the chitosan depolymerization reaction aiming at the production of monomers without the use of additional enzymes or mineral acids. MATERIALS AND METHODS: In this work, we systematically study the effect of sodium nitrite concentration and reaction conditions (pH and temperature ranges) with acetic acid as the solvent on the chitosan depolymerization reaction aiming at the production of monomers, specifically 2,5- anhydromannose, without the use of additional enzymes or mineral acids. RESULTS: The results indicate that only a small range of reaction conditions and nitrite concentrations allow for obtaining the monomer, while in most combinations of these parameters, oligomers are obtained. We found that the temperature decisively affects the reaction yield, with the attainment of 2,5-anhydromannose favored at lower temperatures. CONCLUSION: The method proved to be simple and easy to perform allowing to obtain 2,5- anhydromannose with the use of low-cost reagents. This monomer can be converted into several derivatives for industrial application (5-Hydroxymethylfurfural, ethanol, etc.).
Assuntos
Quitosana , Ácidos , Quitina/química , Quitosana/química , Hexoses , Ácido Nitroso/químicaRESUMO
This study investigated the biocomposite pectin films enriched with murta (Ugni molinae T.) seed polyphenolic extract and reinforced by chitin nanofiber. The structural, morphological, mechanical, barrier, colorimetric, and antioxidant activity of films were evaluated. The obtained data clearly demonstrated that the addition of murta seed extract and the high load of chitin nanofibers (50%) provided more cohesive and dense morphology of films and improved the mechanical resistance and water vapor barrier in comparison to the control pectin film. The antioxidant activity ranged between 71% and 86%, depending on the film formulation and concentration of chitin nanofibers. The presented results highlight the potential use of chitin nanofibers and murta seed extract in the pectin matrix to be applied in functional food coatings and packaging, as a sustainable solution.