A bi-site mechanism for Escherichia coli F-1-ATPase accounts for the observed positive catalytic cooperativity

作者：Bulygin Vladimir V; Milgrom Yakov M^*

来源：Biochimica et Biophysica Acta-Bioenergetics, 2009, 1787(8): 1016-1023.

DOI：10.1016/j.bbabio.2009.02.025

• ATP synthase
• Catalytic cooperativity
• Bi-site catalysis
• Tri-site catalysis
• Nucleotide binding
• Centrifugal filtration

Nucleotide binding to nucleotide-depleted F-1-ATPase from Escherichia coli (EcF(1)) during MgATP hydrolysis in the presence of excess e subunit has been studied using a combination of centrifugal filtration and column-centrifugation methods. The results show that nucleotide-binding properties of catalytic sites on EcF(1) are affected by the state of occupancy of noncatalytic sites. The ATP-concentration dependence of catalytic-site occupancy during MgATP hydrolysis demonstrates that a bi-site mechanism is responsible for the positive catalytic cooperativity observed during multi-site catalysis by EcF(1). The results suggest that a bi-site mechanism is a general feature of F-1 catalysis.

• 出版日期2009-8