The plant cytolytic protein enterolobin assumes a dimeric structure in solution

Abstract

Enterolobin is a plant cytolytic protein similar to the bacterial cytolysin aerolysin. Biochemical and biophysical techniques were used to verify if enterolobin, like aerolysin, adopts a dimeric structure in solution. SDS-PAGE showed bands corresponding to enterolobin monomer, dimer and oligomers, whilst gel filtration chromatography and electrospray mass spectrometry revealed preferred association of enterolobin as a dimer. Atomic force microscopy (AFM) of enterolobin showed images of a dimer assembly at a concentration as low as 10 microg/ml, similarly to aerolysin. The enterolobin in silico docked structure is coherent with AFM enterolobin dimer shapes.