Banca de QUALIFICAÇÃO: YAMARA ARRUDA SILVA DE MENEZES
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.DISCENTE : YAMARA ARRUDA SILVA DE MENEZES
DATA : 29/06/2018
HORA: 15:00
LOCAL: Sala SS1 - Departamento de Biologia Celular e Genética
TÍTULO:
PROTEOMIC AND BIOLOGICAL CHARACTERIZATION OF SCORPIONS VENOM OF THE GENUS Tityus
PALAVRAS-CHAVES:
Tityus stigmurus. Scorpion venom. Bottom-up proteomics. Biological characterization.
PÁGINAS: 135
GRANDE ÁREA: Ciências Biológicas
ÁREA: Bioquímica
RESUMO:
Scorpions of the genus Tityus belong to the Buthidae family and are responsible for most of the reported envenomation accidents in Brazil. Envenomation is often characterized by local symptoms as pain, paresthesia, edema and erythema. Scorpion venoms are complex mixtures containing many toxic peptides and proteins. The study of toxic composition of scorpion venoms are especially important for the development of effective treatments for cases of scorpionism. Additionally, toxins are molecules that may to have potential biotechnological applications. In this study, we present the proteomic and functional characterization of the Brazilian scorpion venom Tityus stigmurus. T. stigmurus is widely distributed in the northeastern region of the country and recognized as the main species responsible for envenomation of medical importance and although studies for this species have been carried out, a large number of venom components remain unknown. The proteomic characterization of soluble fraction of T. stigmurus venom (TstiV) was performed by bottom-up proteomics using liquid chromatography tandem mass spectrometry (LC-MS/MS) performed in a LTQ (Linear Trap Quadrupole) Orbitrap Velos. Peptide spectrum matching (PSM) search was performed using the PatternLab platform, and de novo sequencing using PEAKS Studio 8.0. The databases containing all the protein entries for order Scorpiones from UniProtKB (UniPro Knowledgebase) and NCBI (National Center for Biotechnology Information), and protein amounts was estimated using the normalized spectral abundance factor (NSAF). For the functional characterization, enzymatic assays as phospholipase A2, hyaluronidase and fibrinogenolytic, PT and aPTT tests, antimicrobial activity, cell viability assay, nitric oxide (NO) production, lethality determination and evaluation of effects of envenomation were performed. Proteomic analyzes for TstiV showed the presence of 6 new families of toxins, including calcine, calcium channel toxins, bradykinin potentiating peptide, serine proteases, protease inhibitor and phospholipases A2. The ion channel toxins account for approximately 70% of the peptides identified. No toxic effects were observed in RAW 264.7, VERO E6 and 3T3 cells, as well as modulating effect of nitric oxide production on macrophages. However, TstiV showed high toxicity for BALB/c mice (LD50 = 0.575 mg/kg). TstiV presented hyaluronidase, anticoagulant and fibrinogenolytic activity, the latter with the important participation of metalloprotease enzymes. The biological tests associated with the technology of proteomic analysis contributed to a better elucidation of the composition and characterization of T. stigmurus venom. This approach presents the most complete depiction of the molecular repertoire for TstiV, source of molecules with potential biotechnological application.
MEMBROS DA BANCA:
Externo à Instituição - ARIANE FERREIRA LACERDA - UFRN
Externo ao Programa - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR
Presidente - 2085604 - SUSANA MARGARIDA GOMES MOREIRA