Anion atpases from rainbow trout gills showing high and low anion affinity.
1. Chloride-bicarbonate ATPase shows two affinity constants for the bicarbonate ion; a low affinity constant (Km=12.5mEq/1) and a high affinity constant (Km=0.17mEq/1), suggesting that two separate enzymes may exist. 2. In the presence of 5mEq/1 Cl- the low affinity Km is increased to 2.5mEq/1. 3. Chloride alone does not activate the enzyme, but in the presence of 4mEq/1 HCO3- the Km value is 5mEq/1.
Battram
J C
JC
Department of Biological Sciences, The University, Dundee, Scotland.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D027321:Anion Transport Proteins; D001639:Bicarbonates / Q000378:metabolism* / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism* / Q000494:pharmacology; D004789:Enzyme Activation; D005880:Gills / Q000201:enzymology*; D007700:Kinetics; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*
D027321:Anion Transport Proteins; D001639:Bicarbonates; D002712:Chlorides; D000251:Adenosine Triphosphatases; C031652:anion-sensitive ATPases