An essential arginine residue at the substrate-binding site of p-hydroxybenzoate hydroxylase.
نویسندگان
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 کاملConformational dynamics of the isoalloxazine in substrate-free p-hydroxybenzoate hydroxylase: single-molecule studies.
p-Hydroxybenzoate hydroxylase (PHBH) is a homodimeric enzyme in which each subunit noncovalently binds one molecule of FAD in the active site. PHBH is a model system for how flavoenzymes regulate reactions with oxygen. We report single-molecule fluorescence studies of PHBH in the absence of substrate that provide data consistent with the hypothesis that a critical step in substrate binding is t...
متن کاملAn Essential Arginine Residue in Porcine Phospholipase
Reaction of phenylglyoxal, a reagent specific for arginine residues, with porcine phospholipase Az results in complete elimination of catalytic activity. The modification reaction is markedly dependent on pH. Other dicarbonyl compounds such as 2,3-butanedione and 1,2cyclohexanedione also react with the enzyme to cause loss of activity but at significantly slower rates. At pH 7.0, the inactivati...
متن کاملOn the stable enzyme-substrate complex of p-hydroxybenzoate hydroxylase. Evidences for the proton uptake from the substrate.
p-Hydroxybenzoate hydroxylase (EC 1.14.13.2) from Pseudomonas desmolytica is known to form a stable complex with its substrate. Investigations were made on properties of the complex by spectrophotometric measurements and photooxidation. The addition ofp-hydroxybenzoate or benzoate to the oxidized (with respect to bound FAD) enzyme solution caused changes in absorption, fluorescence, and CD spec...
متن کاملEvidence for an essential arginine residue at the active site of ATP citrate lyase from rat liver.
Rat liver ATP citrate lyase was inactivated by 2, 3-butanedione and phenylglyoxal. Phenylglyoxal caused the most rapid and complete inactivation of enzyme activity in 4-(2-hydroxyethyl)-1-piperazine-ethanesulphonic acid buffer, pH 8. Inactivation by both butanedione and phenylglyoxal was concentration-dependent and followed pseudo- first-order kinetics. Phenylglyoxal also decreased autophosphor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1980
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(19)70564-x