A B S T R A C T Although pyridoxal phosphate is known to inhibit gelation of purified hemoglobin S, antisickling activity has never been demonstrated for intact erythrocytes. We incubated washed erythrocytes at 370C either in buffer alone, or with added pyridoxal phosphate or pyridoxal, washed these cells, suspended them in untreated buffer, and compared the percent modified hemoglobin, the oxy...

SUMMARY The searchable mutant database PLPMDB has been developed to provide rapid and simple access to relevant mutant information on pyridoxal-5'-phosphate dependent enzymes. All data have been extracted from publications and publicly available databases, then organized in a relational database to enable searching via a web-based search form. The current version of PLPMDB contains 688 mutants ...

BACKGROUND There have been many studies of the effect of high-dose supplementation of vitamin B6 on children and adults with autism, with all but one reporting benefits. OBJECTIVE The aim of this study was to investigate the biochemical basis for vitamin B6 therapy by measuring the level of total vitamin B6 in the plasma of unsupplemented children with autism spectrum disorder compared to uns...

5-Aminolevulinate synthase of Rhodopseudomonas spheroides interacts with its cofactor, pyridoxal phosphate, and shows an absorption maximum at 430 nm with a probable shoulder at 320--330 nm. The enzyme-PLP complex absorbing at 430 nm is the predominant species at pH 7.2 and can be reduced by NaBH4 at neutral pH with a spectral shift of the absorption maximum to 325 nm. These data suggests the f...

Tyrosine phenol-lyase (EC 4.1.99.2) from Citrobacter freundii has been cloned and the primary sequence deduced from the DNA sequence. From the BrCN digest of the NaBH4-reduced holoenzyme, five peptides were purified and sequenced. The amino acid sequences of the peptides agreed with the corresponding parts of the tyrosine phenol-lyase sequence obtained from the gene structure. K257 is the pyrid...

F’yridoxal kinase has been purified 2,000-fold from pig brain. The enzyme preparation migrates as a single protein and activity band on analytical gel electrophoresis. Pyridoxal kinase, 60,000 molecular weight, catalyzes the phosphorylation of pyridoxal (K,,, = 2.5 x 10m5 M) and pyridoxine (K, = 1.7 X lo-’ M). Pyridoxamine is not a substrate of the purified kinase. Irradiation of the kinase in ...

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)-...

Glutamine synthetase (Escherichia coli) was incubated with three different reagents that react with lysine residues, viz. pyridoxal phosphate, 5'-p-fluorosulfonylbenzoyladenosine, and thiourea dioxide. The latter reagent reacts with the epsilon-nitrogen of lysine to produce homoarginine as shown by amino acid analysis, nmr, and mass spectral analysis of the products. A variety of differential l...