Biomaterial Database

The kinetics of Schiff-base formation during reconstitution of D-serine apodehydratase from Escherichia coli with pyridoxal 5'-phosphate. 1979

T A Reed, and K D Schnackerz

Schiff base formation during reconstitution of D-serine dehydratase (Escherichia coli) from its apoenzyme and pyridoxal 5'-phosphate (pyridoxal-P) has been studied by rapid kinetic techniques using absorbance changes at 436 nm. Three distinct reaction phases have been observed. The first is a very rapid change during which pyridoxal-P is initially bound to the apoenzyme. This step has an equilibrium constant of 1500 M-1 and a forward reaction rate of the order of 2.6 x 10(6) M-1 s-1. The second phase shows a first-order rate constant with a value dependent on pyridoxal-P and corresponds to a first-order step with a forward rate constant of 3.04 s-1 interacting with the initial equilibrium. The final phase is a slow first-order reaction, the rate constant of which is approximately 0.01 s-1 and is independent of pyridoxal-P concentration. The active pyridoxal species has been shown to be the free pyridoxal-P as opposed to hemiacetal or hemimercaptal forms.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008239	Lysine	An essential amino acid. It is often added to animal feed.	Enisyl,L-Lysine,Lysine Acetate,Lysine Hydrochloride,Acetate, Lysine,L Lysine
D008623	Mercaptoethanol	A water-soluble thiol derived from hydrogen sulfide and ethanol. It is used as a reducing agent for disulfide bonds and to protect sulfhydryl groups from oxidation.	2-ME,2-Mercaptoethanol,2 Mercaptoethanol
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
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D001051	Apoenzymes	The protein components of enzyme complexes (HOLOENZYMES). An apoenzyme is the holoenzyme minus any cofactors (ENZYME COFACTORS) or prosthetic groups required for the enzymatic function.	Apoenzyme
D012545	Schiff Bases	Condensation products of aromatic amines and aldehydes forming azomethines substituted on the N atom, containing the general formula R-N:CHR. (From Grant & Hackh's Chemical Dictionary, 5th ed)	Schiff Base,Base, Schiff,Bases, Schiff
D012695	L-Serine Dehydratase	A PYRIDOXAL-phosphate containing enzyme that catalyzes the dehydration and deamination of L-serine to form pyruvate. This enzyme was formerly listed as EC 4.2.1.13.	Serine Deaminase,Serine Dehydratase,L-Serine Ammonia-Lyase,Serine-Threonine Dehydratase,Ammonia-Lyase, L-Serine,Deaminase, Serine,Dehydratase, L-Serine,Dehydratase, Serine,Dehydratase, Serine-Threonine,L Serine Ammonia Lyase,L Serine Dehydratase,Serine Threonine Dehydratase
D013057	Spectrum Analysis	The measurement of the amplitude of the components of a complex waveform throughout the frequency range of the waveform. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Spectroscopy,Analysis, Spectrum,Spectrometry
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures