scholarly journals Product inhibition studies on bovine liver carbamoyl phosphate synthetase

1974 ◽  
Vol 141 (3) ◽  
pp. 817-824 ◽  
Author(s):  
Keith R. F. Elliott ◽  
Keith F. Tipton
Keyword(s):  
Inorganic Phosphate ◽  
Substrate Binding ◽  
Inorganic Ions ◽  
Bovine Liver ◽  
Product Inhibition ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate ◽  
Product Release ◽  
Proposed Model ◽  
Inhibition Studies

A study of the product-inhibition patterns of carbamoyl phosphate synthetase from bovine liver is reported. Inhibition by adenosine, AMP and inorganic ions is also reported. The results are in agreement with the previously proposed model in which the order of substrate binding is ATPMg, followed by HCO3−, ATPMg and NH4+. The order of product release on the basis of the reported results is carbamoyl phosphate, followed by ADPMg, ADPMg and inorganic phosphate.

scholarly journals A catalytic mechanism for the enzyme benzylamine oxidase from pig plasma

1972 ◽  
Vol 130 (3) ◽  
pp. 713-728 ◽  
Author(s):  
C. E. Taylor ◽  
R. S. Taylor ◽  
C. Rasmussen ◽  
P. F. Knowles
Keyword(s):  
Catalytic Mechanism ◽  
Product Inhibition ◽  
Chemical Mechanism ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Independent Evidence ◽  
Product Release ◽  
Benzylamine Oxidase ◽  
Inhibition Studies ◽  
Substrate Addition

Initial-velocity and product-inhibition studies on the enzyme benzylamine oxidase from pig plasma indicate that the order of substrate addition and product release is benzylamine on, ammonia off, oxygen on, hydrogen peroxide off, benzaldehyde off. Ammonia, but not benzaldehyde, is released under strictly anaerobic conditions which provides independent evidence for this order. Benzyl alcohol is a substrate for the enzyme. A chemical mechanism consistent with all the data is proposed.

Characterization of the reaction mechanism for the XL-I form of bovine liver xenobiotic/medium-chain fatty acid:CoA ligase

2001 ◽  
Vol 357 (1) ◽  
pp. 283-288 ◽  
Author(s):  
Donald A. VESSEY ◽  
Michael KELLEY
Keyword(s):  
Reaction Mechanism ◽  
Bovine Liver ◽  
Liver Mitochondria ◽  
Product Inhibition ◽  
Bivalent Cation ◽  
Medium Chain ◽  
Apparent Homogeneity ◽  
Ping Pong ◽  
Inhibition Studies

The XL-I form of xenobiotic/medium-chain fatty acid:CoA ligase was purified to apparent homogeneity from bovine liver mitochondria and used to determine the reaction mechanism. A tersubstrate kinetic analysis was conducted by varying the concentrations of ATP, benzoate and CoA in turn. Both ATP and benzoate gave parallel double-reciprocal plots against CoA, which indicates a Ping Pong mechanism, with either pyrophosphate or AMP leaving before the binding of CoA. Addition of pyrophosphate to the assays changed the plots from parallel to intersecting; addition of AMP did not. This indicates that pyrophosphate is the product that leaves before binding of CoA. Based on end-product inhibition studies, it was concluded that the reaction follows a Bi Uni Uni Bi Ping Pong mechanism, with ATP binding first, followed in order by benzoate binding, pyrophosphate release, CoA binding, benzoyl-CoA release and AMP release. A similar mechanism was obtained when the ligase was examined with butyrate as substrate. However, butyrate activation was characterized by a much higher affinity for CoA. This is attributed to steric factors resulting from the bulkier nature of the benzoate molecule. Also, with butyrate there is a bivalent cation activation distinct from that associated with binding to ATP. This activation by excess Mg2+ results in non-linear plots of 1/v against 1/[ATP] for butyrate unless the concentrations of Mg2+ and ATP are varied together.

scholarly journals Kinetic studies of bovine liver carbamoyl phosphate synthetase

1974 ◽  
Vol 141 (3) ◽  
pp. 807-816 ◽  
Author(s):  
Keith R. F. Elliott ◽  
Keith F. Tipton
Keyword(s):  
Initial Rate ◽  
Kinetic Studies ◽  
Bovine Liver ◽  
Kinetic Mechanism ◽  
Rate Equations ◽  
British Library ◽  
Rate Data ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate ◽  
Lending Library

A through study of initial-rate data has been made on carbamoyl phosphate synthetase from bovine liver. On the basis of the results the order of substrate binding to the enzyme is ATPMg followed by HCO3−, ATPMg and NH4+. A model for the enzymic mechanism is proposed, and the rate equations describing it are presented. Details of the derivation of the initial-rate equation for the kinetic mechanism proposed have been deposited as Supplementary Publication SUP 50032 (6 pages) at the British Library, Lending Division (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7QB, U.K., from whom copies may be obtained on the terms indicated in Biochem. J. (1973), 131, 5.

Inactivation by acivicin of carbamoyl-phosphate synthetase II of human colon carcinoma

1985 ◽  
Vol 34 (1) ◽  
pp. 97-100 ◽  
Author(s):  
Judith S. Sebolt ◽  
Takashi Aoki ◽  
John N. Eble ◽  
John L Glover ◽  
George Weber
Keyword(s):  
Colon Carcinoma ◽  
Human Colon ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate ◽  
Human Colon Carcinoma

Spatial relationships among the active and allosteric sites of carbamoyl-phosphate synthetase

1985 ◽  
Vol 13 (2) ◽  
pp. 98-109 ◽  
Author(s):  
Philip G. Kasprzyk ◽  
Eric Whalen-Pederson ◽  
Paul M. Anderson ◽  
Joseph J. Villafranca
Keyword(s):  
Spatial Relationships ◽  
Carbamoyl Phosphate Synthetase ◽  
Carbamoyl Phosphate ◽  
Allosteric Sites
Sign in / Sign up

Export Citation Format

Share Document