FLAVOENZYME CATALYSIS. SUBSTRATE-COMPETITIVE INHIBITION OF d-AMINO ACID OXIDASE

On the Interpretation of the Absorption Spectra of Flavoproteins with Special Reference to D-Amino Acid Oxidase*

“…While it is considered that the primary binding force in complex formation is a salt linkage involving a positively charged group of the protein and an ionized carboxyl group of the complexing agent, the binding strength of many derivatives appears too great for this to be the only linkage involved. In agreement with the inhibition studies of Frisell et al (1956), the com- pounds that are most strongly bound to the enzyme are those with an ,/3-unsaturated conjugation. It is perhaps some interaction between such a linkage and the conjugated ring structure of the flavin that is the cause of the enhanced binding strength of this group of compounds.…”

Light-mediated reduction of flavoproteins with flavins as catalysts

“…Influence of the Competitive Inhibitor, Benzoate, on the Photoreduction of d-Amino Acid Oxidase. Benzoate is a potent competitive inhibitor of D-amino acid oxidase (Frisell et al, 1956) and its effects on the physical properties of the enzyme have been studied in some detail (Yagi and Ozawa, 1962; elsdenii, 19-20 µ with respect to FMN content, in 0.05 M phosphate, pH 6.5, and 0.025 M EDTA, was made anaerobic and subjected to 15-s illumination periods at 25 °C as described under Materials and Methods. It was necessary to wait 5-10 min after each irradiation for dark changes to become complete.…”

Design and Synthesis of Enantiomers of 3,5-Dinitro-o-tyrosine: α-Amino-3-hydroxy-5-methyl-4-isoxazolepropanoic Acid (AMPA) Receptor Antagonists

“…17 However Parikh et al have shown that attempts to prepare the L-isomers of phenylalanine, tryptophan, tyrosine, and hydroxyproline by using D-AAOx led to products largely contaminated with the respective D-isomers. 14 Hellermann et al 18 have shown that D-AAOx is considerably inhibited by many aromatic compounds such as benzoic acid, phenylpyruvic acid, and indole-2-carboxylic acid. Therefore, we predicted that the oxidation of (R)-o-tyrosine with the D-AAOx would be effectively hindered by the products of the reaction.…”

“…After the column was loaded and washed it with H2O (2 L) and EtOH (500 mL), the amino acid was eluted with 0.3 M NH4OH. The eluent was concentrated under reduced pressure to 5 mL, pH was adjusted to ∼3.5 with 1 N HCl, and 6a was crystallized as yellow crystals which had optical purity of >99% ee: yield 0.19 g (31%); mp 235-240 °C; 1 H NMR (DMSO-d6, 300 MHz) δ 8.54-8.53 (d, 1H, J ) 3.1 Hz, ArH), 7.89-7.88 (d, 1H, ArH), 4.14-4.11 (m, 1H, CH), 3.12-3.06 (dd, 1H, Jvic ) 3.8 Hz, Jgem ) 14.0 Hz, CH2), 2.89-2.82 (dd, 1H, Jvic ) 7.4 Hz, CH2); 13 (R,S)-N-(tert-Butoxycarbonyl)-o-tyrosine (18). o-Tyrosine (13) (1.0 g, 5.5 mmol) was dissolved in a mixture of H2O (30 mL), 2 N NaOH (10 mL), and THF (30 mL).…”