Split intein converting peptide protein interaction into electrochemically assisted metal ion catalytic signal in the prenatal screening of pediatric epilepsy.

ABSTRACT

Dravet syndrome is a rare form of epilepsy starting from infancy that can plaque the affected individuals all though his/her life with repeated seizures, and this condition is currently without a complete cure. So prenatal screening of molecular markers of this condition is urgently needed to help couples conceiving new lives to steer clear of this potential danger. And such an assay should ideally be of low cost and could be completed in a point-of-care fashion. This work reports an attempt to construct such an assay using simple peptides in the place of conventional biosensing macro-molecules such as antibodies and enzymes. Specifically, a marker protein of this syndrome can bring the two pieces of a self-splitting peptide "intein" together, which in turn facilitate the formation of metal ion coordination site, recruiting cupric ion to generate catalytically amplified signal readout. Using this method, disease marker protein Nav of this syndrome can be quantitatively detected directly in amniotic fluid samples, and samples associated with potential risk factors such as family history of this syndrome shows statistically evident decrease of this marker protein. These results may promise future application of the proposed method in clinical practice to reduce the social burden of Dravet syndrome by reducing its actual incident rate.