Mestrado em Bioquímica
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- ItemLectinas do muco cutâneo do peixe-escorpião Scorpaena plumieri : caracterização bioquímica e investigação do potencial biotecnológico(Universidade Federal do Espírito Santo, 2025-12-08) Souza, Pricila Meier; Gonçalves, Juliana Barbosa Coitinho ; https://orcid.org/0000-0002-5892-050X; http://lattes.cnpq.br/3448669742301744; Figueiredo, Suely Gomes de ; https://orcid.org/0000-0002-5363-8329; http://lattes.cnpq.br/5470652664331084; https://orcid.org/0009-0000-8214-7871; http://lattes.cnpq.br/6231516957082476; Pires, Rita Gomes Wanderley ; https://orcid.org/0000-0002-4739-8349; http://lattes.cnpq.br/8356031036198869; Campos, Fabiana Vasconcelos ; https://orcid.org/0000-0002-1132-3257; http://lattes.cnpq.br/8900863576455523Lectins are proteins that recognize carbohydrates, especially those present in glycoconjugates, and participate in essential biological processes such as cell communication, immune response, infections, apoptosis, and metastasis, which makes them molecules of high biotechnological potential. Considering that fish skin mucus is a promising source of these proteins, this study aimed to purify and characterize lectins present in the mucus of Scorpaena plumieri. Two isolectins, designated LecSpM-I and LecSpM-II, were purified by gel filtration chromatography (Sephacryl S-200). Analyses by MALDI-TOF MS and LC-MS/MS revealed that both lectins form homodimers, whose monomers exhibit molecular masses of 15,858 Da (LecSpM-I) and 13,022 Da (LecSpM-II), and indicated that they are isoforms homologous to plumieribetin, a type B lectin previously described in the venom of this fish species. SDS-PAGE/PAS and immunoblot assays confirmed the glycoprotein nature and oligomeric state of the purified proteins. The LecSpMs exhibited moderate cytotoxicity, promoting a reduction in metabolic cell viability (MCV) in tumor (C6 and RKO) and non-tumor (HEK293 and RAW) cell lines, as demonstrated in resazurin assays. In addition, they displayed antithrombotic activity by inhibiting collagen induced platelet aggregation, suggesting a possible functional interaction with key mediators of hemostasis. The purification and initial characterization of these lectins represent an essential step toward understanding their chemical and biological properties. The results obtained reinforce the biotechnological potential of fish mucus lectins, with possible applications in oncology, hemostasis, and glycobiology, as well as expanding knowledge on the molecular diversity of skin mucus and highlighting marine organisms as relevant sources of bioactive biomolecules
- ItemEstratégias para quantificar Ocratoxina A em amostras de café: estudo de interferentes, pré-tratamentos e análise computacional(Universidade Federal do Espírito Santo, 2025-07-29) Mancini, Isabela Fracalossi; Santos, Gabriel Fernandes Souza dos ; https://orcid.org/0000-0002-8798-6428; http://lattes.cnpq.br/2884729106673212; Oliveira, Jairo Pinto de; https://orcid.org/0000-0001-7595-1183; http://lattes.cnpq.br/2228283301316218; https://orcid.org/0009-0006-2698-6957; http://lattes.cnpq.br/5521119724911165; Guimarães, Marco Cesar Cunegundes; https://orcid.org/0000-0003-2146-0180; http://lattes.cnpq.br/0261991057482057; Antunes, Paulo Wagnner Pereira; http://lattes.cnpq.br/5259147170249880Ochratoxin A (OTA) is a mycotoxin produced by fungi of the Aspergillus and Penicillium genera that can be found in various food products and is particularly relevant in the context of coffee production. Due to its high toxicity, each region has its own regulations to ensure safe maximum consumption limits of this substance in coffee beans. The quantification of OTA is commonly performed using methodologies that involve immunoaffinity columns (IACs) as a pre-treatment step, followed by high performance liquid chromatography with fluorescence detection (HPLC-FL). However, components of the coffee matrix can directly influence the efficiency of OTA recognition by IAC antibodies. Therefore, the present study investigated individually the influence of some coffee markers (caffeine, caffeic acid, chlorogenic acid, cafestol, acrylamide, and melanoidins) on OTA detection, as well as their effects in different types of coffee. The assays were performed by pre-treating the samples using IACs followed by HPLCFL detection, and also employing rapid tests (Lateral Flow Immunoassay, LFIA). The results showed that nearly all interferents were capable of reducing OTA recovery in the tests. Caffeine and caffeic acid yielded the lowest recoveries in the HPLC-FL tests, with values of 65.17% and 69.39%, respectively. In the LFIA tests, chlorogenic acid and melanoidins resulted in the lowest recoveries, with only 48.45% and 35.74%, respectively. Computational molecular docking studies were carried out, and the in silico results were compared with the tests performed. The findings indicate that the reduction in toxin recovery may be related to possible interactions with OTA, mainly through hydrogen interactions or π-π bonds.
- ItemPurificação e caracterização de lectina(s) de Xanthosoma sagittifolium (L.) Schott (taioba): hemaglutinina(s) com potencial efeito citotóxico(Universidade Federal do Espírito Santo, 2025-03-19) Paiva, Ana Paula Passos de; Gonçalves, Juliana Barbosa Coitinho; https://orcid.org/0000-0002-5892-050X; http://lattes.cnpq.br/3448669742301744; https://orcid.org/0009-0000-7612-0090; http://lattes.cnpq.br/1797554469669361; Oliveira, Jairo Pinto de; https://orcid.org/0000-0001-7595-1183; http://lattes.cnpq.br/2228283301316218; Costa, Mariana Amalia Figueiredo; https://orcid.org/0000-0002-8539-3063; http://lattes.cnpq.br/2806425060879128Lectins are carbohydrate-binding proteins that appear in all domains of life and, due to their ability to bind specifically and reversibly to carbohydrate glycoconjugates through specific sites/domains - being known as agglutinins - they play an essential role in various biological processes. The antimicrobial and antitumor potential of these proteins has been explored for the development of alternative drugs and/or adjuvants. The presence of lectins in the leaves and roots of various plant species has been described, which are associated with inflammatory responses, antioxidant capacity, antiproliferative and pro-apoptotic effects of these plants. This work aimed to purify and characterize – biochemically and functionally – hemagglutinating fractions - lectin(s) - from Xanthosoma sagittifolium (L.) – Taioba – an Unconventional Food Plant (UFP). The purification process was monitored by hemagglutination and SDS-PAGE assays (presence of bands with a molecular mass between 12-14 kDa - the monomeric unit of lectins). Hemagglutinating fractions were obtained by sequenced saline precipitation ((NH4)2SO4 15% and 35%) from the protein extract of leaves and roots. The fraction of the leaf extract precipitated at 15% was selected for the continuation of the purification process – molecular exclusion chromatography in an HPLC system – from which two partially purified hemagglutinating fractions were obtained. The protein profile of these fractions showed bands with the molecular mass of the monomeric unit and its multiples, suggesting the formation of supramolecular arrangements, a common characteristic of lectins. It was shown that the hemagglutinating fractions (P15 and P35 from leaves) have mannose binding specificity and do not differentiate between blood types (ABO). P15 from the taioba leaf also showed an optimum pH between 7,5 and 7,9 and an optimum temperature of 37°C, being dependent on the magnesium ion. Using the resazurin-based cell viability assay, it was shown that the hemagglutinating fractions - from molecular exclusion - were cytotoxic in a dose-dependent manner (~ 0. 1 µg to 53 µg), 1 µg to 53 µg) for the cancerous cell lines of rat glioma (C6), human colon carcinoma (RKO) and primary malignant human ovarian adenocarcinoma (TOV-21G), except for the human glioblastoma tumor line (U373), reducing viability by up to 78%. Preliminary tests did not identify any antifungal activity for Trichoderma reesei. In this work, two hemagglutinating fractions with cytotoxic potential were partially purified, which represents the first steps towards their complete biochemical andfunctional characterization, as well as the exploration of their biotechnological potential.
- ItemAção da mitoquinona, um antioxidante mitocondrial, sobre o metabolismo mitocondrial cardíaco após infarto agudo do miocárdio(Universidade Federal do Espírito Santo, 2025-02-26) Traichel, Geórgia Azevedo Oliveira; Stefanon, Ivanita ; https://orcid.org/0000-0003-2638-5183; http://lattes.cnpq.br/8456612999765726; Fernandes, Aurélia Araújo; https://orcid.org/0000-0001-9945-1909; http://lattes.cnpq.br/5478728158150003; https://orcid.org/0009-0002-9695-3414; http://lattes.cnpq.br/0106389990223853; Vieira, Maicon Landim; https://orcid.org/0000-0002-6696-8888; http://lattes.cnpq.br/5216391153452438; Amorim, Girlandia Alexandre Brasil ; https://orcid.org/0000-0002-5455-7141; http://lattes.cnpq.br/1402295792093274Ischemic heart disease is one of the leading causes of heart failure (HF), with mitochondria playing a central role in the progression of this condition. Mitochondrial oxidative stress, alterations in cardiac bioenergetic pathways, and the activation of apoptotic signaling in cardiac tissue are key contributors of this process. In this context, identifying therapeutic strategies capable of directly targeting mitochondrial dysfunction is essential. This study aimed to evaluate the effects of mitoquinone (MitoQ) on mitochondrial function in infarcted rats treated for seven days. Male Wistar rats (aged 10 to 12 weeks) were randomly assigned to three groups: Sham, MI and MI MitoQ. Animals underwent surgery for myocardial infarction (MI) induction or a sham surgical procedure. Mitoquinone (MitoQ) treatment was administered in drinking water for seven days. Cardiac function was assessed by echocardiography, and weight data were analysed. As expected, the MI group showed a reduced ejection fraction and right ventricular hypertrophy, effects that were not reversed by the treatment. However, MitoQ attenuated pulmonary congestion. Additionally, the MI group exhibited an approximately 50% reduction in mitochondrial protein yield (YIELD), which was not restored with short-term treatment. Nevertheless, MitoQ improved mitochondrial calcium retention, enhanced mitochondrial coupling and ATP synthesis capacity, optimized complex I function, and reestablished beta-oxidation. Therefore, our findings suggest that MitoQ was effective in mitigating changes associated with mitochondrial dysfunction and may represent a promising complementary therapeutic strategy for ischemic heart disease, potentially supporting cardiac remodeling after infarction
- ItemPotencial efeito neuroprotetor do canabidiol em um modelo pré-clínico da doença de parkinson(Universidade Federal do Espírito Santo, 2024-10-18) Toledo, João Gabriel Assis; Pires, Rita Gomes Wanderley; https://orcid.org/0000-0002-4739-8349; https://orcid.org/http://lattes.cnpq.br/8356031036198869; https://orcid.org/0009-0008-9696-8679; http://lattes.cnpq.br/1148485070900089; Hollais, André Willian; https://orcid.org/0000-0002-2991-8646; http://lattes.cnpq.br/0068789063590867; Silva, Sarah Martins Presti da; https://orcid.org/0000-0003-2579-4866; http://lattes.cnpq.br/0768873502799973Parkinson's disease (PD) is the second most common neurodegenerative disease, second only to Alzheimer's disease. PD is characterized by the death of dopaminergic neurons in the substantia nigra pars compacta, leading to a decrease in dopamine release in the striatum region. The increase in cases of death and disability from PD has increased more than any other neurodegenerative disease, however, there is still no cure or treatment that reduces the progression of PD, making the search for new treatment methods and drug candidates that promote such effects imperative. The gold standard medication for the treatment of Parkinson's disease, levodopa, brings with it some problems with prolonged use, such as levodopa-induced dyskinesia, which is often worse than the disease itself. In this context, Cannabidiol (CBD), a non-psychoactive compound extracted from the Cannabis sativa plant, has shown promise, as there are several studies demonstrating its potential neuroprotective effect in different neurological diseases and also a possible indication for the treatment of levodopa-induced dyskinesia. Swiss mice were treated for 21 days with rotenone and two hours later cannabidiol was administered, and at the end of the treatment motor tests (open field and rotarod) were performed for biochemical analyses of the content of dopamine, serotonin and their metabolites by HPLC, in addition to the expression of tyrosine hydroxylase by Western Blotting. From the results obtained, there was no statistical difference in the results found in the open field test, however there was a significant difference in the latency to fall from the rotarod test apparatus, however, this difference was not found with the biochemical parameters both by Western Blotting and by HPLC. The data found in this work suggest a behavioral alteration that was not reflected in biochemical alterations and new experiments should be carried out with other doses of both rotenone and CBD.