The anionic conjugates of bilirubin and bile acids stimulate ATP hydrolysis by S-(dinitrophenyl)glutathione ATPase of human erythrocyte.
These studies demonstrate that bilirubin-ditaurate (an analog of bilirubin-diglucuronide), lithocholic acid 3-O-sulfate, and lithocholic acid 3-O-glucuronide, which are believed to be transported from liver into bile through an active transport process stimulate ATP hydrolysis by purified dinitrophenylglutathione ATPase of human erythrocytes. The Km and Vmax values of the enzyme for these substrates are similar to those for dinitrophenylglutathione indicating the transport mechanisms for bilirubin conjugates, and anionic bile acid-conjugates from hepatocytes to bile and transport of GSH-conjugates from erythrocytes may be mediated by similar mechanisms.
Singhal
S S
SS
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77550.
Sharma
R
R
Gupta
S
S
Ahmad
H
H
Zimniak
P
P
Radominska
A
A
Lester
R
R
Awasthi
Y C
YC
D000251:Adenosine Triphosphatases / Q000097:blood* / Q000302:isolation & purification; D000255:Adenosine Triphosphate / Q000097:blood*; D001647:Bile Acids and Salts / Q000097:blood*; D004910:Erythrocyte Membrane / Q000201:enzymology*; D005965:Glucuronates / Q000097:blood*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D013379:Substrate Specificity; D013464:Sulfuric Acids / Q000097:blood
D001647:Bile Acids and Salts; D005965:Glucuronates; D013464:Sulfuric Acids; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C068387:S-(dinitrophenyl)glutathione ATPase