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A minimum catalytic unit of F 1 ‐ATPase shows non‐cooperative ATPase activity inherent in a single catalytic site with a K m 70 μ M
Author(s) -
Saika Koji,
Yoshida Masasuke
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00644-o
Subject(s) - atpase , catalysis , kinetics , protein subunit , chemistry , enzyme , enzyme kinetics , thermophile , stereochemistry , biophysics , active site , crystallography , biochemistry , biology , physics , quantum mechanics , gene
F 1 ‐ATPase has three interacting catalytic sites and shows complicated kinetics. Here, we report reconstitution of a complex, most likely composed of one α subunit and one β subunit, with a single catalytic site from thermophilic Bacillus PS3 F 1 ‐ATPase on the solid surface. The complex has an ATPase activity which obeys a simple non‐cooperative kinetics with a K m (ATP) of 70 μ M and a V max of 0.1 unit/mg. Different from F 1 ‐ATPase, the complex is not inactivated by 7‐chrolo‐4‐nitrobenzofrazan. Thus, the inherent activity attributable to a single catalytic site unaffected by other catalytic sites of F 1 ‐ATPase is characterized.