Proteins in the insulin-secreting cell line MIN6 bind the imidazoline compound BL11282

The imidazoline BL11282 stimulates insulin release and alters islet proteomes. Subcellular fractions of MIN6 cells showed that the membrane fraction exhibited binding to BL11282 on a Biacore chip and to BL11282-labelled magnetic beads. Bound material extracted from the beads showed a ∼50 kDa differential band upon SDS–PAGE and a weaker 100 kDa band. The former was sensitive to competitive removal by preincubation of the fraction with BL11282, then highlighting the ∼100 kDa band. Masspectrometric analysis revealed the ∼50 kDa band to be EF1A and the ∼100 kDa band to be glucose regulated P94, both of interest in insulin synthesis and secretion.