Banca de QUALIFICAÇÃO: Reynaldo Magalhães Melo

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Reynaldo Magalhães Melo
DATE: 21/03/2023
TIME: 09:00
LOCAL: Microsoft Teams
TITLE:

"Integration of top-down and bottom-up proteomics for the proteoform characterization of microorganism with medical and biotechnological relevance."

KEY WORDS:

Proteomics, top-down, bottom-up, Post-translational modification, Proteoforms, Corynebacterium glutamicum, Trypanosoma cruz

PAGES: 74
BIG AREA: Ciências Biológicas
AREA: Biologia Geral
SUMMARY:

Proteomics is an approach capable of quantifying proteins and identifying post-translational modifications (PTMs), and widely used for the characterization of biological processes in several organisms. Currently, the most practiced proteomic approaches are bottom-up (BU) and top-down (TD), the former performs the analysis of proteins’ tryptic peptides, while the second analyzes intact proteins directly. The integration of both approaches has improved the identification and characterization of proteoforms, helping to localize PTMs and even identify proteoforms. The integration of BU and TD proteomic data has already been used in microorganisms such as Neisseria meningitidis and Escherichia coli, characterizing new proteoforms with clinical relevance, in N. meningitidis, and with potential biotechnological relevance, in E. coli. The bacterium Corynebacterium glutamicum is an important industrial platform, mainly in the production of amino acids, in addition to having phylogenetic proximity to other bacteria of clinical relevance. Chagas disease, caused by the protozoan Trypanosoma cruzi, affects between 6 and 7 million people worldwide, mainly in Latin America. Considering the biotechnological relevance of C. glutamicum, the medical importance of T. cruzi, and the potential of integration of BU and TD approaches, this study performed qualitative and quantitative proteomic analyzes on these two microorganisms, using both proteomic approaches. In C. glutamicum, the TD proteomic analysis was performed, revealing new proteoforms of the OdhI protein, with putative crotonaldehyde or butyrylation, revealing possible implications in the glutamate metabolism of this organism. In addition, other proteins with biotechnological relevance such as mepB were identified by a truncated proteoform, suggesting an activation mechanism from the cleavage of its Nterminus. Furthermore, some oxidative stress response proteins were also identified by new proteoforms, suggesting regulatory mechanisms not described in them. Quantitative BU proteomic analysis of T. cruzi amastigote cells under replicative and non-replicative conditions revealed 1106 regulated proteins (q-value < 0.05), and a large number of proteins with highly different abundance between conditions. Among the highly regulated proteins present are trans-sialidases, Leishmanolysin-like peptidases, and kDNA-associated proteins.

BANKING MEMBERS:
Externa à Instituição - LYRIS MARTINS FRANCO DE GODOY - FIOCRUZ
Interna - 2222088 - ELIANE FERREIRA NORONHA
Externo ao Programa - 404947 - MARCELO VALLE DE SOUSA
Presidente - 2594909 - SEBASTIEN OLIVIER CHARNEAU