TY - EJOUR
AU - Mahinpour, Roya
AU - Ghasemi, Majid
AU - Moosavi-Nejad, Zahra
AU - Zahraie, Zohreh
PY - 2024
DA - February
TI - Caffeine effect on adenosine deaminase catalysis: A new look at the effect of caffeine on adenosine deaminase activity
T2 - Iranian Journal of Catalysis
VL - 6
L1 - https://oiccpress.com/iranian-journal-of-catalysis/article/caffeine-effect-on-adenosine-deaminase-catalysis-a-new-look-at-the-effect-of-caffeine-on-adenosine-deaminase-activity/
N2 - The effect of physiological concentrations of caffeine (purified from Persian tea) on adenosine deaminase (ADA) activity at physiological and pathological concentrations of adenosine (as substrate) in 50 mM Tris-HCl buffer (pH 7.3) at 37°C was investigated, using UV-VIS spectroscopy. ADA exhibited a bi-phasic activity behavior and both phases showed positive cooperativities indicating adenosine has at least two regulatory sites on ADA molecule. We proposed a mechanism for the inhibitory effect of caffeine on ADA catalytic activity by analyzing ADA kinetic behavior at various physiological concentrations of caffeine (10, 30, 70 mM): Caffeine dominantly resulted in decreased catalytic activity of ADA via reducing the positive homotropic effect of adenosine on ADA activity. Surprisingly, it also showed a very weak but significant activatory effect on ADA activity in a concentration-dependent manner. To the best of our knowledge, this is the first report on the dual effect of caffeine on ADA activity.  
IS - 5
PB - OICC Press
KW - Inhibition, Homotropic effect, Caffeine, Adenosine deaminase 
EN -