Screening assay for inhibitors of a recombinant Streptococcus pneumoniae UDP-glucose pyrophosphorylase

Abstract

The UDP-glucose pyrophosphorylase of Streptococcus pneumoniae (GalU_Spn) is absolutely required for the biosynthesis of capsular polysaccharide, the sine qua non virulence factor of pneumococcus. Since the eukaryotic enzymes are completely unrelated to their prokaryotic counterparts, we propose that the GalU enzyme is a critical target to fight the pneumococcal disease. A recombinant GalU_Spn was overexpressed and purified. An enzymatic assay that is rapid, sensitive and easy to perform was developed. This assay was appropriate for screening chemical libraries for searching GalU inhibitors. This work represents a fundamental step in the exploration of novel antipneumococcal drugs.

Keywords:

• Antibacterial target
• pneumococcus
• UTP:glucose 1-phosphate uridylyltransferase
• virulence inhibitors

Acknowledgements

The CIBER de Enfermedades Respiratorias (CIBERES) is an initiative of the Instituto de Salud Carlos III (ISCIII). We thank A. Iglesias and C. Figueroa for providing advice in the enzymatic assay.

Disclosure statement

The authors report no competing interests.

Additional information

Funding

This work has been sponsored by grants from Universidad de Buenos Aires, Agencia Nacional de Promoción Científica y Tecnológica, ANPCYT and Dirección General de Investigación Científica y Técnica (SAF2012-39444-C02-01). LB, MM, GL, MVM and AM are members of “Carrera del Investigador”, CONICET, Argentina. Consejo Nacional de Investigaciones Científica y Técnicas [11220110100707CO], Agencia Nacional de Promoción Científica y Tecnológica, ANPCYT [PICT-2008- 2214], Dirección General de Investigación Científica y Técnica [SAF2012-39444-C02-01], Secretaria de Ciencia y Tecnica, Universidad de Buenos Aires [20020090300074].