Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.1 (phosphodiesterase)
 18,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Denaturation of recombinant sarcosine oxidase or the natural enzyme isolated from Corynebacterium sp. P-1 with guanidine hydrochloride releases noncovalently bound FAD and a second UV-absorbing component (peak 2) which comigrates with NAD+ during reversed-phase HPLC. Both FAD and peak 2 are also found in extracts prepared by incubating sarcosine oxidase at 37 degrees C for 30 min, a procedure which causes partial (approximately 50%) release of the enzyme's noncovalently bound FAD. Peak 2 in the 37 degrees C extract is heat labile and decomposes upon boiling for 5 min at pH 8.0. A similar instability was observed with NAD+. Reaction of the 37 degrees C extract from sarcosine oxidase with phosphodiesterase yields nicotinamide mononucleotide, AMP, and FMN, as expected for a mixture containing NAD+ and FAD. Peak 2 was converted to NADH upon reaction of the 37 degrees C extract with yeast alcohol dehydrogenase in the presence of ethanol. Guanidine hydrochloride extracts, prepared from recombinant or natural enzyme, contain 1 mol of NAD+/mol of FAD. Since sarcosine oxidase contains 1 mol of noncovalently bound FAD, the results show that the enzyme also contains 1 mol of NAD+. The NAD+ is tightly bound and is not lost during enzyme purification. It is not susceptible toward hydrolysis by NADase, reduction by alcohol dehydrogenase, or nucleophilic attack by cyanide. Unlike the flavins in sarcosine oxidase, NAD+ is not reduced by sarcosine and is not in redox equilibrium with the flavins.
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PMID:Discovery of a third coenzyme in sarcosine oxidase. 852 44

Sarcosine oxidase from Corynebacterium sp. P-1 is a heterotetrameric protein containing three different enzymes: noncovalent FAD, noncovalent NAD+, and covalently bound flavin which is released as 8 alpha-(N3-histidyl)riboflavin upon complete hydrolysis of the protein. The following results show that the covalent flavin is not at the FAD level, as previously proposed, but it is rather as 8 alpha-(N3- histidyl)FMN coenzyme. First, no AMP is released when the protein moiety is treated with phosphodiesterase or subjected to mild acid hydrolysis. The enzyme contains a total of 5 mol of phosphate. Only one phosphate is covalently bound. The other four phosphates are noncovalent and attributed to noncovalently bound FAD and NAD+. The 31P NMR spectrum of native enzyme exhibits resonances due to a single phosphate monoester an two pyrophosphates. Only a resonance due to phosphate monoester is observed after removal of the noncovalent cofactors and proteolytic digestion of the protein moiety. The 8 alpha-(N3-histidyl)FMN found in corynebacterial sarcosine oxidase represents a novel type of covalent flavin. Studies with sarcosine oxidases from Arthrobacter sp. and Pseudomonas sp. show that these heterotetrameric enzymes also contain covalently bound FMN plus noncovalently bound FAD and NAD+, similar to corynebacterial sarcosine oxidase. In contrast, two monomeric sarcosine oxidases (from Bacillus sp. and an unidentified microorganism) were found to contain only covalently bound FAD.
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PMID:Sarcosine oxidase contains a novel covalently bound FMN. 861 16

Monomeric sarcosine oxidase (MSOX) and N-methyltryptophan oxidase (MTOX) are homologous enzymes that catalyze the oxidative demethylation of sarcosine (N-methylglycine) and N-methyl-L-tryptophan, respectively. MSOX is induced in various bacteria upon growth on sarcosine. MTOX is an E. coli enzyme of unknown metabolic function. Both enzymes contain covalently bound flavin. The covalent flavin is at the FAD level as judged by electrospray mass spectrometry. The data provide the first evidence that MTOX is a flavoprotein. The following observations indicate that 8alpha-(S-cysteinyl)FAD is the covalent flavin in MSOX from Bacillus sp. B-0618 and MTOX. FMN-containing peptides, prepared by digestion of MSOX or MTOX with trypsin, chymotrypsin, and phosphodiesterase, exhibited absorption and fluorescence properties characteristic of an 8alpha-(S-cysteinyl)flavin and could be bound to apo-flavodoxin. The thioether link in the FMN-containing peptides was converted to the sulfone by performic acid oxidation, as judged by characteristic absorbance changes and an increase in flavin fluorescence. The sulfone underwent a predicted reductive cleavage reaction upon treatment with dithionite, releasing unmodified FMN. Cys315 was identified as the covalent FAD attachment site in MSOX from B. sp. B-0618, as judged by the sequence obtained for a flavin-containing tryptic peptide (GAVCMYT). Cys315 aligns with a conserved cysteine in MSOX from other bacteria, MTOX (Cys308) and pipecolate oxidase, a homologous mammalian enzyme known to contain covalently bound flavin. There is only one conserved cysteine found among these enzymes, suggesting that Cys308 is the covalent flavin attachment site in MTOX.
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PMID:Structure of the flavocoenzyme of two homologous amine oxidases: monomeric sarcosine oxidase and N-methyltryptophan oxidase. 1022 Mar 47