Disruption of active site interactions with pyridoxal 5'-phosphate and substrates by conservative replacements in the glycine-rich loop of Escherichia coli D-serine dehydratase
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چکیده
منابع مشابه
D-Serine dehydratase from Escherichia coli. Essential arginine residue at the pyridoxal 5'-phosphate binding site.
D-Serine apodehydratase from Escherichia coli is rapidly inactivated by butanedione in K+ borate buffer or by phenylglyoxal in K+ phosphate buffer at pH 8, 25 degrees. Pyridoxal-P protects against the inactivation. Modification of the apoenzyme abolishes its ability to bind the cofactor, pyridoxal-P, but the apparent Km for the substrate, D-serine, is not altered. The concentration dependence o...
متن کاملThe mechanism of addition of pyridoxal 5'-phosphate to Escherichia coli apo-serine hydroxymethyltransferase.
Previous studies suggest that the addition of pyridoxal 5'-phosphate to apo-serine hydroxymethyltransferase from Escherichia coli is the last event in the enzyme's folding process. We propose a mechanism for this reaction based on quenched-flow, stopped-flow and rapid-scanning stopped-flow experiments. All experiments were performed with an excess of apo-enzyme over cofactor, since excess pyrid...
متن کاملAspartate transcarbamylase from Escherichia coli. The use of pyridoxal 5'-phosphate as a probe in the active site.
Spectrophotometric titration studies at pH 8.0 have revealed that pyridoxal 5’-phosphate binds as a Schiff base to the catalytic subunit of Escherichia coli aspartate transcarbamylase with a stoichiometry of 3 pyridoxal phosphates per trimer and a dissociation constant of 0.9 pM. The ultraviolet absorption of the Schiff base near 430 nm is lost upon addition of the inhibitor N-(phosphonacetyl)-...
متن کاملInteractions between tryptophan synthase from Escherichia coli and derivatives of the coenzyme pyridoxal 5'-phosphate.
Coenzyme Derivatives, Pyridoxal 5'-Phosphate, Tryptophan Synthase The interaction of the coenzyme analogues pyridoxal (A), pyridoxine 5'-phosphate (B), pyridoxic acid 5'-phosphate (Q and N-phosphopyridoxyl-L-serine (D) with both the isolated apo ß2 subunit and the native <x2 apo ß2 bienzyme complex of tryptophan synthase from Escherichia coli has been investigated using enzyme kinetics and CD s...
متن کاملCrystal structure of the pyridoxal-5'-phosphate-dependent serine dehydratase from human liver.
L-serine dehydratase (SDH), a member of the beta-family of pyridoxal phosphate-dependent (PLP) enzymes, catalyzes the deamination of L-serine and L-threonine to yield pyruvate or 2-oxobutyrate. The crystal structure of L-serine dehydratase from human liver (hSDH) has been solved at 2.5 A-resolution by molecular replacement. The structure is a homodimer and reveals a fold typical for beta-family...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1990
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(17)30521-5