Banca de QUALIFICAÇÃO: PRISCILA SABBAG FERREIRA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PRISCILA SABBAG FERREIRA
DATE: 13/07/2023
TIME: 14:00
LOCAL: Banca a ser realizada no campus de Santo André
TITLE:

STUDY OF CHOLESTEROL PRESENCE IN MONOLAYERS OF DIPALMITOYLPHOSPHATIDYLCHOLINE AND INTERACTION OF PROTEINS RELATED TO SARS-CoV-2

PAGES: 90
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Físico-Química
SPECIALTY: Química de Interfaces
SUMMARY:

In 2019 the novel coronavirus, SARS-CoV-2, was identified as the pathogen of coronavirus disease 2019 (COVID-19) and has spread worldwide, becoming a public health emergency of international concern. Recent studies show that patients who have a high level of cholesterol in the body are more likely to contract this disease (ZAKI; ALASHWAL; IBRAHIM, 2020). The biochemical and biophysical processes related to this disease are highly complex, so studying model systems capable of mimicking the interaction between cell membranes and proteins associated with the SARS-CoV-2 coronavirus has proved to be unpredictable. Thus, in this work we propose to study changes in the interface of monolayers composed of DPPC that serve as a cell membrane model in the presence and absence of cholesterol (SUBCZYNSKI; PASENKIEWICZ-GIERULA; WIDOMSKA; MAINALI et al., 2017) with Spike proteins and the receptor binding domain (RBD). For this, the Langmuir and Langmuir-Blodgett (LB) techniques were used, as well as atomic force microscopy (AFM) small angle X-ray scattering (SAXS) and electrochemical techniques.

We observed the presence of cholesterol in the DPPC monolayers promotes local modification inducing the formation of more rigid membrane regions. All the results obtained in this work led us to the conclude lipid membranes cholesterol-rich promotes an increase in protein incorporation in the membrane, especially the Spike protein. Combining the results of the adsorption isotherms together with the structural SAXS parameters we were able to suggest a structural model of how these proteins were immersed in the membrane. In the case of the Spike protein is more capable to incorporating into the lipid membrane while the RBD tends to be allocated in the interfacial region of the membrane, corroborating the AFM images and surface potential data. The electrochemistry experiments helped us confirm that the lipid membrane can be used as a template model for organizations of these proteins and that increasing their concentration can self-assemble at the membrane interface.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1309493 - PEDRO ALVES DA SILVA AUTRETO
Membro Titular - Examinador(a) Interno ao Programa - 050.966.059-22 - MURILO SANTHIAGO - CNPEM
Membro Titular - Examinador(a) Externo ao Programa - 1544365 - GISELLE CERCHIARO
Membro Suplente - Examinador(a) Interno ao Programa - 2605463 - JOSE ANTONIO SOUZA
Membro Suplente - Examinador(a) Interno ao Programa - 1734908 - FABIO FURLAN FERREIRA
Membro Suplente - Examinador(a) Externo ao Programa - 1909336 - ALEXANDRE ZATKOVSKIS CARVALHO