tailieunhanh - Báo cáo khoa học: Modeling of ATP–ADP steady-state exchange rate mediated by the adenine nucleotide translocase in isolated mitochondria

A computational model for the ATP–ADP steady-state exchange rate med-iated by adenine nucleotide translocase (ANT) versus mitochondrial mem-brane potential dependence in isolated rat liver mitochondria is presented. The model represents the system of three ordinary differential equations, and the basic components included are ANT, F0 ⁄F1 -ATPase, and the phos-phate carrier. | Modeling of ATP-ADP steady-state exchange rate mediated by the adenine nucleotide translocase in isolated mitochondria Eugeniy Metelkin1 Oleg Demin1 2 Zsuzsanna Kovacs3 and Christos Chinopoulos4 1 Institute for Systems Biology SPb Moscow Russia 2 A. N. Belozersky Institute of Physico-ChemicalBiology Moscow State University Russia 3 Department of PharmaceuticalChemistry Semmelweis University Budapest Hungary 4 Department of MedicalBiochemistry Semmelweis University Budapest Hungary Keywords adenine nucleotide carrier adenine nucleotide translocator ATP synthasome ATP ADP carrier systems biology Correspondence C. Chinopoulos Department of Medical Biochemistry Semmelweis University Tuzolto st. 37-47 1094 Budapest Hungary Fax 361 2670031 Tel 361 4591500 ext. 60024 E-mail Received 3 June 2009 revised 20 September 2009 accepted 23 September 2009 doi A computational model for the ATP-ADP steady-state exchange rate mediated by adenine nucleotide translocase ANT versus mitochondrial membrane potential dependence in isolated rat liver mitochondria is presented. The model represents the system of three ordinary differential equations and the basic components included are ANT Fq F1-ATPase and the phosphate carrier. The model reproduces quantitatively the relationship between mitochondrial membrane potential and the ATP-ADP steady-state exchange rate mediated by the ANT operating in the forward mode with the assumption that the phosphate carrier functions under rapid equilibrium. Furthermore the model can simulate the kinetics of experimentally measured data on mitochondrial membrane potential titrated by an uncoupler. Verified predictions imply that the ADP influx rate is highly dependent on the mitochondrial membrane potential and in the 0-100 mV range it is close to zero owing to extremely low matrix ATP values. In addition to providing theoretical values of free matrix ATP and ADP the model explains the .