| First Author | Abrams CJ | Year | 1996 |
| Journal | J Physiol | Volume | 493 ( Pt 3) |
| Pages | 643-9 | PubMed ID | 8799888 |
| Mgi Jnum | J:37363 | Mgi Id | MGI:84761 |
| Doi | 10.1113/jphysiol.1996.sp021411 | Citation | Abrams CJ, et al. (1996) The role of a single aspartate residue in ionic selectivity and block of a murine inward rectifier K+ channel Kir2.1. J Physiol 493(Pt 3):643-9 |
| abstractText | 1. The effects of Rb+ and Cs+ as blocking ions were investigated on wild-type and mutant forms of the inward rectifier K+ channel, IRK1 (Kir2.1). 2. In wild-type channels, Rb+ blockage was voltage dependent, increasing and then falling with increasing hyperpolarization. 3. Rb+ blockage was abolished by replacing Asp172 in the M2 domain of the pore-forming subunit by Asn, but was re-established by a change to Gln, narrowing the pore. Blocking affinity was reduced in D172Q, and was also reduced by replacing Gly168 in M2 by Ala. 4. Cs+ blockage was also abolished in D172N but was re-established in D172Q. 5. There appears to be a balance between charge and pore size in determining whether ions block or permeate. A major part of the selectivity of Kir2.1 is associated with Asp172 in the M2 domain. |
