Open AccessReactive blue 2 is a potent inhibitor of a thylakoid protein kinase
Author(s) -
COUGHLAN Sean J.,
DAVENPORT James W.,
HIND Geoffrey
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb15933.x
Subject(s) - biochemistry , protein kinase a , chemistry , enzyme , thylakoid , kinase , membrane , protein kinase inhibitor , substrate (aquarium) , non competitive inhibition , biophysics , biology , chloroplast , gene , ecology
The anthraquinone dye reactive blue 2 was found to be a potent inhibitor of a protein kinase isolated and purified from thylakoids. This enzyme was also inhibited in situ , with corresponding inhibition of ATP‐dependent quenching of the chlorophyll fluorescence. The mode of inhibition was noncompetitive, with a K i of 8 μM for the membrane‐bound kinase, and 6 μM for the purified kinase. The inhibitor did not modify the substrate preference of the endogenous kinase and could be removed from the membrane by washing. Unlike reactive blue 2, the enzyme did not partition into detergent micelles and is therefore presumably not a hydrophobic, intrinsic membrane protein.