Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/32040
Title: Conformational analysis of Pneumococcal Surface Antigen A (PsaA) upon zinc binding by fluorescence spectroscopy
Authors: Ano Bom, Ana Paula D.
Corrêa, Izabella B.S. Correa
Argondizzo, Ana Paula C.
Medeiros, Marco Alberto
Santos, Roger B. dos
Souza, Theo Luiz F. de
Silva Junior, Jose G. da
Affilliation: Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.
Universidade Federal do Rio de Janeiro. Faculdade de Farmácia. Rio de Janeiro, RJ, Brasil.
Universidade Federal do Rio de Janeiro. Faculdade de Farmácia. Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz. Instituto de Tecnologia em Imunobiológicos. Rio de Janeiro, RJ, Brasil.
Abstract: PsaA (pneumococcal surface antigen A) is a S. pneumoniae virulence factor that belongs to the metal transport system. The Manganese PsaA binding has been associated with oxidative stress resistance becoming a pivotal element in the bacteria virulence. It has been shown that Zinc inhibits the Manganese acquisition and promotes bacteria toxicity. We have performed a PsaA conformational analysis both in the presence (Zn-rPsaA) and in the absence of Zinc (free-rPsaA). We performed experiments in the presence of different Zinc concentrations to determine the metal minimum concentration which induced a conformational change. The protein in free and Zn-binding condition was also studied in pH ranging 2.6-8.0 and in temperature ranging 25oC-85oC. pH experiments showed a decrease of fluorescence intensity only in acidic medium. Analysis of the heat-induced denaturation demonstrated that Zinc-binding promoted an increase in melting temperature from 55oC (free-rPsaA) to 78.8oC (Zn-rPsaA) according to fluorescence measurements. In addition, the rPsaA stabilization by Zinc was verified through analysis of urea and guanidine hydrochloride denaturation. Data showed that Zinc promoted an increase in the rPsaA stability and its removal by EDTA can lead to a PsaA intermediate conformation. These findings can be considered in the development of vaccines containing PsaA as antigen.
Keywords: Conformational analysis
rPsaA
Zinc
Stability
Streptococcus Pneumoniae
Issue Date: 2018
Citation: ANO BOM, Ana Paula D. et al . Conformational analysis of Pneumococcal Surface Antigen A (PsaA) upon zinc binding by fluorescence spectroscopy. An. Acad. Bras. Ciênc., Rio de Janeiro, v. 90, n. 2, supl. 1, p. 2299-2310, 2018 .
DOI: 10.1590/0001-3765201820170151
ISSN: 1678-2690
Copyright: open access
Appears in Collections:Biomanguinhos - Artigos de Periódicos

Files in This Item:
File Description SizeFormat 
0001-3765-aabc-201820170151.pdf2.4 MBAdobe PDFView/Open


FacebookTwitterDeliciousLinkedInGoogle BookmarksBibTex Format mendeley Endnote DiggMySpace

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.