Cloning, expression and purification of proteins of surface, PsaA and fragments of PspA from Streptococcus pneumoniae / Clonagem, expressão e purificação das proteínas de superfície, PsaA e fragmentos de PspA de Streptococcus pneumoniae

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Streptococcus pneumoniae is the main causative agent of bacterial pneumonia. The current vaccines available contain capsular polysaccharide conjugated or not with carrier proteins. However these are either too expensive or do not protect the high-risk groups. Surface proteins of S. pneumoniae, such as PsaA and PspA, are considered strong vaccine candidates. With the aim of developing a broad-coverage and low-cost vaccine against pneumococcus, the psaA and pspA genes were cloned in E. coli expression vectors, pAE and pET and the expressed proteins were purified through affinity and anion exchange chromatography. The yield of the recombinant protein obtained with the construction based in pET was 3-fold higher than that obtained with pAE. Culture conditions were established using defined media with IPTG and/or lactose induction. The recombinant strains are now ready to undergo studies for scale-up of production in bioreactors.

ASSUNTO(S)

vaccines streptococcus steptococcus pneumococos pneumonia clonagem purificação de psaa e pspa vacinas genic expression pneumococcus proteínas recombinantes cloning purification of psaa and pspa recombinant proteins

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