There is disclosed a nucleic acid molecule encoding a VMH KATP channel subunit designated SUR1b DELTA 33 comprising the amino acid sequence according to SEQ ID No 2 or the amino acid sequence of a functional equivalent, derivative or bioprecursor thereof. The subunit expressed also forms part of the invention. A VMH KATP channel comprising a Kir6.x subunit and a SUR1b DELTA 33 subunit is also disclosed.
