Biomaterial Database

Citrate lyase deacetylase of Rhodopseudomonas gelatinosa. Isolation of the enzyme and studies on the inhibition by L-glutamate. 1980

F Giffhorn, and H Rode, and A Kuhn, and G Gottschalk

Citrate lyase deacetylase or acetyl-S-(acyl-carrier protein) enzyme thioester hydrolase (acetate) (EC 3.1.2-), was purified 3100-fold with a yield of 3.8% from cell extracts of Rhodopseudomonas gelatinosa. The final enzyme preparation gave a single protein band upon polyacrylamide-gel electrophoresis in the absence or in the presence of sodium dodecylsulfate. The molecular weight of the native enzyme was estimated by gel filtration to be 14 300 +/- 1000. Sodium dodecylsulfate/polyacrylamide gel electrophoresis yielded a molecular weight of 7300 +/- 600 indicating that the enzyme consisted of two subunits. Citrate lyase deacetylase acted as an S-acetyl enzyme thioesterhydrolase because it catalyzed the conversion of citrate lyase (S-acetyl form) into citrate lyase (sulfhydryl form) and acetate. Citrate lyase deacetylase was strongly inhibited by L-glutamate. The half-maximal inhibitor concentration was 7.5 X 10(-4) M. and a Ki-value of 1.2 X 10(-4) M was determined. The mode of inhibition appeared to be of the linear mixed type. L-Glutamate was bound by citrate lyase deacetylase but not by citrate lyase. The pool concentrations of L-glutamate in R. gelatinosa were 10 mM when citrate was present in substrate amounts and 2.7 mM after total consumption of citrate. Simulation of conditions in vivo using homogeneous enzyme preparations of citrate lyase and citrate lyase deacetylase, and glutamate concentrations of 10 mM and 2.7 mM respectively, revealed that the rate of citrate lyase inactivation increased from 8% within 15 min during growth on citrate to 50% within 15 min in the absence of citrate.

UI	MeSH Term	Description	Entries
D007652	Oxo-Acid-Lyases	Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.	Ketoacid-Lyases,Ketoacid Lyases,Oxo Acid Lyases
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D005971	Glutamates	Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.	Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D012241	Rhodopseudomonas	A genus of gram-negative, rod-shaped, phototrophic bacteria found in aquatic environments. Internal photosynthetic membranes are present as lamellae underlying the cytoplasmic membrane.
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D013869	Thiolester Hydrolases		Hydrolases, Thiolester