An aldosterone regulated chicken intestine protein with high affinity to amiloride.
The pattern of chicken intestine amiloride-binding proteins was determined using the photoreactive amiloride analogue 2'-methoxy-5'-nitrobenzamil (NMBA) and a polyclonal anti-amiloride antibody. At 10(-7)M, NMBA inhibits approximately 62% of the Na+ channel activity. At this concentration the amiloride analogue labels a number of membrane proteins, and in particular a 40-45 kDa polypeptide denoted ABP40. Incorporation of NMBA into ABP40 could be prevented by a 100-fold excess of benzamil, but not by a 1000-fold excess of 5-(N-ethyl-N-isopropyl)-amiloride. Labeling of ABP40 was intense in membranes derived from salt-deprived chickens and approximately 5-fold weaker in membranes from salt-repleted animals. Because of its small size, ABP40 is not likely to be an avian Na+ channel subunit, yet this amiloride-binding protein could be involved in the response to aldosterone.
Goldstein
O
O
Department of Membrane Research And Biophysics, Weizmann Institute Of Science, Rehovot, Israel.
Asher
C
C
Cragoe
E
E
Kleyman
T R
TR
Garty
H
H
D000450:Aldosterone / Q000502:physiology*; D000584:Amiloride / Q000378:metabolism*; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D004232:Diuretics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding
D004232:Diuretics; D008565:Membrane Proteins; D000450:Aldosterone; D000584:Amiloride