TY - JOUR
T1 - Succinic Thiokinase of Escherichia Coli. Purification, Phosphorylation of the Enzyme, and Exchange Reactions Catalyzed by the Enzyme
AU - Grinnell, Frederick Lawrence
AU - Nishimura, Jonathan S.
PY - 1969/12/1
Y1 - 1969/12/1
N2 - Succinic thiokinase (succinate:coenzyme A ligase (adenosine diphosphate, EC 6.2.1.5) has been isolated in highly purified form from Escherichia coli (ATCC 4157) by a procedure which includes DEAEcellulose chromatography and gel filtration on Sephadex G-150. Assuming a molecular weight of141,000 (Ramaley, R. F., Bridger, W. A., Moyer, R. W., and Boyer, P. D. (1967), J. Biol. Chem. 242 (4287), close to two phosphoryl groups are incorporated per mole of enzyme, whether the phosphorylating agent is adenosine triphosphate or inorganic phosphate (in the presence of succinyl-coenzyme A). Capability for phosphorylation appears to be related to enzyme activity and extent of phosphorylation by adenosine triphosphate is not significantly affected by coenzyme A at 2.5 × 10-5 m. At this concentration coenzyme A strongly stimulates the adenosine triphosphate ⇄ adenosine diphosphate exchange reaction catalyzed by the enzyme. It has been concluded that under these conditions coenzyme A is not bound covalently or involved in a high-energy nonphosphorylated form of the enzyme. It has also been found that inorganic phosphate is an almost complete requirement for the succinate ⇄ succinyl coenzyme A exchange reaction catalyzed by the enzyme, adding support to the hypothesis that enzyme-bound succinyl phosphate is an intermediate in the over-all reaction.
AB - Succinic thiokinase (succinate:coenzyme A ligase (adenosine diphosphate, EC 6.2.1.5) has been isolated in highly purified form from Escherichia coli (ATCC 4157) by a procedure which includes DEAEcellulose chromatography and gel filtration on Sephadex G-150. Assuming a molecular weight of141,000 (Ramaley, R. F., Bridger, W. A., Moyer, R. W., and Boyer, P. D. (1967), J. Biol. Chem. 242 (4287), close to two phosphoryl groups are incorporated per mole of enzyme, whether the phosphorylating agent is adenosine triphosphate or inorganic phosphate (in the presence of succinyl-coenzyme A). Capability for phosphorylation appears to be related to enzyme activity and extent of phosphorylation by adenosine triphosphate is not significantly affected by coenzyme A at 2.5 × 10-5 m. At this concentration coenzyme A strongly stimulates the adenosine triphosphate ⇄ adenosine diphosphate exchange reaction catalyzed by the enzyme. It has been concluded that under these conditions coenzyme A is not bound covalently or involved in a high-energy nonphosphorylated form of the enzyme. It has also been found that inorganic phosphate is an almost complete requirement for the succinate ⇄ succinyl coenzyme A exchange reaction catalyzed by the enzyme, adding support to the hypothesis that enzyme-bound succinyl phosphate is an intermediate in the over-all reaction.
UR - http://www.scopus.com/inward/record.url?scp=0014473632&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0014473632&partnerID=8YFLogxK
U2 - 10.1021/bi00830a015
DO - 10.1021/bi00830a015
M3 - Article
C2 - 4240087
AN - SCOPUS:0014473632
SN - 0006-2960
VL - 8
SP - 562
EP - 568
JO - Biochemistry
JF - Biochemistry
IS - 2
ER -