Biomaterial Database

Modification of Rhodospirillum rubrum ribulose bisphosphate carboxylase with pyridoxal phosphate. 2. Stoichiometry and kinetics of inactivation. 1978

W B Whitman, and F R Tabita

Rhodospirillum rubrum ribulose bisphosphate carboxylase contains two high affinity binding sites for pyridoxal phosphate and two catalytic sites per dimer. However, pyridoxal phosphate binding at only one site is sufficient for inactivation of both catalytic sites. In the presence of 20 mM bicarbonate, 10 mM magnesium, and pyridoxal phosphate, the rates of inactivation and Schiff base formation are pseudo-first-order and show saturation kinetics. These observations provide additional evidence that pyridoxal phosphate binds at the active site of the R. rubrum carboxylase. It is also proposed that the large subunit may contain regulatory as well as catalytic properties.

UI	MeSH Term	Description	Entries
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
D011732	Pyridoxal Phosphate	This is the active form of VITAMIN B 6 serving as a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. During transamination of amino acids, pyridoxal phosphate is transiently converted into pyridoxamine phosphate (PYRIDOXAMINE).	Pyridoxal 5-Phosphate,Pyridoxal-P,Phosphate, Pyridoxal,Pyridoxal 5 Phosphate,Pyridoxal P
D002262	Carboxy-Lyases	Enzymes that catalyze the addition of a carboxyl group to a compound (carboxylases) or the removal of a carboxyl group from a compound (decarboxylases). EC 4.1.1.	Carboxy-Lyase,Decarboxylase,Decarboxylases,Carboxy Lyase,Carboxy Lyases
D000494	Allosteric Regulation	The modification of the reactivity of ENZYMES by the binding of effectors to sites (ALLOSTERIC SITES) on the enzymes other than the substrate BINDING SITES.	Regulation, Allosteric,Allosteric Regulations,Regulations, Allosteric
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D012247	Rhodospirillum rubrum	Vibrio- to spiral-shaped phototrophic bacteria found in stagnant water and mud exposed to light.
D012273	Ribulose-Bisphosphate Carboxylase	A carboxy-lyase that plays a key role in photosynthetic carbon assimilation in the CALVIN-BENSON CYCLE by catalyzing the formation of 3-phosphoglycerate from ribulose 1,5-biphosphate and CARBON DIOXIDE. It can also utilize OXYGEN as a substrate to catalyze the synthesis of 2-phosphoglycolate and 3-phosphoglycerate in a process referred to as photorespiration.	Carboxydismutase,Ribulose Biphosphate Carboxylase-Oxygenase,Ribulose Diphosphate Carboxylase,Ribulosebiphosphate Carboxylase,Rubisco,1,5-Biphosphate Carboxylase-Oxygenase,Ribulose Biphosphate Carboxylase,Ribulose Bisphosphate Carboxylase,Ribulose-1,5-Biphosphate Carboxylase,Ribulose-1,5-Biphosphate Carboxylase-Oxygenase,Ribulose-1,5-Bisphosphate Carboxylase Small-Subunit,Ribulose-Bisphosphate Carboxylase Large Subunit,Ribulose-Bisphosphate Carboxylase Small Subunit,Rubisco Small Subunit,1,5 Biphosphate Carboxylase Oxygenase,Biphosphate Carboxylase-Oxygenase, Ribulose,Carboxylase Small-Subunit, Ribulose-1,5-Bisphosphate,Carboxylase, Ribulose Bisphosphate,Carboxylase, Ribulose Diphosphate,Carboxylase, Ribulose-1,5-Biphosphate,Carboxylase, Ribulose-Bisphosphate,Carboxylase, Ribulosebiphosphate,Carboxylase-Oxygenase, 1,5-Biphosphate,Carboxylase-Oxygenase, Ribulose Biphosphate,Carboxylase-Oxygenase, Ribulose-1,5-Biphosphate,Diphosphate Carboxylase, Ribulose,Ribulose 1,5 Biphosphate Carboxylase,Ribulose 1,5 Biphosphate Carboxylase Oxygenase,Ribulose 1,5 Bisphosphate Carboxylase Small Subunit,Ribulose Biphosphate Carboxylase Oxygenase,Ribulose Bisphosphate Carboxylase Large Subunit,Ribulose Bisphosphate Carboxylase Small Subunit,Small Subunit, Rubisco,Small-Subunit, Ribulose-1,5-Bisphosphate Carboxylase