• Bulletin of the Korean Chemical Society
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• 제27권6호
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• pp.947-950
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• 2006

• Journal of Nutrition and Health
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• 제28권4호
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• pp.321-330
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• 1995

Concentrations of total vitamin B-6 in human milk as well as individual, B-6 vitamers have important implications for the nutritional management of breast-fed(BF) infants. Vitamin B-6 status was assessed in 3 groups of infants : two groups preterm (PT) BF infants whose mothers were supplemented with 2 or 27mg pyridoxine(PN)-HCI ; a sub group of formula-fed (FF) PT infants. Mothers and infants were assessed weekly during the 28-day post feeding. Throughout the neonatal period, levels of total vitamin B-6 and percentages of pyridoxal(PL) in breast milk were lower in PT than T mothers, even in mothers supplemented with 27mg PN-HCI. Total vitamin B-6 levels in PT milk paralleled maternal supplementation but percentage distributions of B-6 vitamers did not change. Vitamin B-6 intakes of BF preterm infants paralleled their mothers' level of infants in the 2mg group was suggested by vitamin status parameters. Vitamin B-6 inadequacy of infants correlated with their plasma pyridoxal-5-phosphate(PLP) levels and erythrocyte alanine aminotransferase(E-ALAT) activity; all parameters such as plasma PLP, PL/PLP ratio and stimulation % of E-ALAT were highest for FF PT infants. The positive correlation of vitamin B-6 levels in breast milk gestational age may contraindicate its adequacy for some PT infants.

• BMB Reports
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• 제29권4호
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• pp.335-342
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• 1996

Porcine liver cysteinesulfinic acid decarboxylase was purified approximately 460-fold by means of ammonium sulfate fractionation and sequential column chromatographic separation with Sephadex G-100, DEAE-cellulose and hydroxylapatite. The enzyme has a flat pH profile with maximum activity occurring between pH 6.0 and 7.6. Pyridoxal 5'-phosphate must be present in all buffers used for purification procedures in order to stabilize the enzyme. Addition of sulfhydryl reagents such as 2-mercaptoethanol are also necessary to maintain maximum enzyme activity throughout purification. The absorption spectrum shows that cysteinesulfinic acid decarboxylase is a pyridoxal 5' -phosphate-containing protein. The major absorption is at 280 nm with two smaller absorption regions, one at 425 nm which is ascribed to a Schiffs base between pyridoxal phosphate and protein, and another at 325 nm which is thought to be due to the interaction of 2-mercaptoethanol with the Schiffs base. A number of divalent cations tested did not affect enzyme activity with the exception of mercury, copper, and zinc which are inhibitory. The partially purified enzyme has an apparent $K_m$ of 0.94 mM for cysteinesulfinate. Cysteic acid is a competitive inhibitor of the enzyme with a $K_i$ of 1.32 mM. The molecular weight of the enzyme was estimated to be about 79,600 by using Sephadex G-200 column chromatography.

• The Plant Pathology Journal
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• 제39권3호
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• pp.235-244
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• 2023

Acidovorax citrulli (Ac) is a phytopathogenic bacterium that causes bacterial fruit blotch (BFB) in cucurbit crops, including watermelon. However, there are no effective methods to control this disease. YggS family pyridoxal phosphate-dependent enzyme acts as a coenzyme in all transamination reactions, but its function in Ac is poorly understood. Therefore, this study uses proteomic and phenotypic analyses to characterize the functions. The Ac strain lacking the YggS family pyridoxal phosphate-dependent enzyme, AcΔyppAc(EV), virulence was wholly eradicated in geminated seed inoculation and leaf infiltration. AcΔyppAc(EV) propagation was inhibited when exposed to L-homoserine but not pyridoxine. Wild-type and mutant growth were comparable in the liquid media but not in the solid media in the minimal condition. The comparative proteomic analysis revealed that YppAc is primarily involved in cell motility and wall/membrane/envelop biogenesis. In addition, AcΔyppAc(EV) reduced biofilm formation and twitching halo production, indicating that YppAc is involved in various cellular mechanisms and possesses pleiotropic effects. Therefore, this identified protein is a potential target for developing an efficient anti-virulence reagent to control BFB.

• 한국식품과학회지
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• 제9권3호
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• pp.183-189
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• 1977

고정화(固定化) 균체(菌體)를 이용(利用)한 pyridoxal 5'-phosphate(pyridoxal-p)의 연속생산(連續生産)에 관(關)해실험(實驗)하였다. pyridoxine 5'-phosphate (pyridoxine-p) oxidase활성(活性)을 갖는 Pseudomonas polycolor 균체(菌體)와 Catalase 활성(活性)을 갖는 Kloeckera sp. No. 2201균체(菌體)를 효소원(酵素源)으로 사용(使用)하였다. 균체(菌體)는 Polyacrylamide gel에 불용화(不溶化) 시켰으며 동시고정균체(同時固定菌體)의 활성(活性)이 Pseudomonas Polycoler단독고정균체(單獨固定菌體)의 활성(活性)보다 강(强)하였다. 이 결과(結果)는 동시고정균체(同時固定菌體)의 Pyridoxine-p oxidase-cat-alase system은 Pyridoxine-p 산화(酸化)의 부산물(副産物)인 $H_2O_2$를 분해(分解)하므로서 보호효과를 얻을 수 있음을 의미(意味)한다. 동시고정균체(同時固定菌體)와 생균체(生菌體)의 효소활성(酵素活性)에 미치는 최적(最適)pH는 9.0이었고 동시고정균체(同時固定菌體)의 최적온도(最適溫度)는 $45^{\circ}C$로 생균체(生菌體)보다 $5^{\circ}C$높았다. 고정균체(固定菌體)의 Pyridoxine-p oxidase는 $Hg^{2+}$와 몇몇 SH-화합물(化合物)에 의(依)하여 활성화(活性化)되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.736-738
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• 2003

Ornithine decarboxylase (ODC) is the key enzyme in the synthetic pathway of polyamines. This enzyme is a homodimeric and a pyridoxal 5-phosphate (PLP) dependent enzyme. We have isolated, a cDNA clone encoding ODC from brain cDNA library constructed from flounder (Paralichthys olivaceus). The ODC cDNA contained a complete ORF consisting of 460 amino acids and one stop codon with comparison to nucleotide sequences of the flounder, zebrafish and rat ODC genes, the ODC genes were highly conserved. The transcription of ODC was analyzed with reverse transcription-polymerase chain reaction (RT-PCR) species in brain, kidney, liver, and embryo.

• BMB Reports
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• 제55권9호
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• pp.439-446
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• 2022

Pyridoxal 5'-phosphate (PLP)-dependent enzymes are ubiquitous, catalyzing various biochemical reactions of approximately 4% of all classified enzymatic activities. They transform amines and amino acids into important metabolites or signaling molecules and are important drug targets in many diseases. In the crystal structures of PLP-dependent enzymes, organic cofactor PLP showed diverse conformations depending on the catalytic step. The conformational change of PLP is essential in the catalytic mechanism. In the study, we review the sophisticated catalytic mechanism of PLP, especially in transaldimination reactions. Most drugs targeting PLP-dependent enzymes make a covalent bond to PLP with the transaldimination reaction. A detailed understanding of organic cofactor PLP will help develop a new drug against PLP-dependent enzymes.

• Journal of Nutrition and Health
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• 제28권5호
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• pp.426-434
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• 1995

The purpose of this study were to investigate the effect of fasting and vitamin B6 repletion on tissue concentration of pyridoxal 5-phosphate and urinary excreteion of 4-pyridoxic acid in vitamin B6 deficient rats. Sixty six rats(6 per group) were fed either a vitamin B6 deficient diet (-B6) or a control diet (+B6) for 6 weeks and then rats were repleted with +B6 diet for 2 weeks. Rats were fasted for 1 and 3 days and for 3 days after repletion. Pyridoxal 5-phosphate (PLP) concentration in plasma, liver, skeletal muscle, and heart muscle and urinary 4-pyridoxic acid (4-PA) excretion were compared. Fasting resulted in a significant increase in PLP concentration in the plasma, liver and heart muscle of rats fed the -B6 diet. Skeletal muscle PLP concentration was significantly decreased in +B6 rats but not in -B6 rats. Following vitamin B6 repletion, PLP concentration in the plasma, liver and heart muscle in previously -B6 rats was similar to the respective concentration in +B6 rats while PLP concentration in the skeletal muscle of previously -B6 rats increased, but it was not reached to that of +B6 rats. At day 1 and 2 of the fast, urinary 4-PT excretion increased in both +B6 and -B6 rats although there was no supply of vitamin B6 due to fasting. These results suggest that vitami B6 is redistributed as PLP when there is a caloric deficit and PLP is supplied by an endogenous source, possibly PLP bound to skeletal muscle glycogen phosphorylase.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.695-703
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• 1999

We have studied the stereospecificities of various pyridoxal 5'-phosphate (PLP) dependent enzymes for the hydrogen transfer between the C-4' of a bound coenzyme and the C-2 of a substrate in the transamination catalyzed by the enzymes. Stereospecificities reflect the structures of enzyme active-sites, in particular the geometrical relationship between the coenzyme-substrate Schiff base and the active site base participating in an $\alpha$-hydrogen abstraction. The PLP enzymes studied so far catalyze only a si-face specific (pro-S) hydrogen transfer. This stereochemical finding suggests that the PLP enzymes have the same topological active-site structures, and that the PLP enzymes have evolved divergently from a common ancestral protein. However, we found that o-amino acid aminotransferase, branched chain L-amino acid aminotransferase, and 4-amino-4-deoxychorismate lyase, which have significant sequence homology with one another, catalyze a re-face specific (pro-R) hydrogen transfer. We also showed that PLP-dependent amino acid racemases, which have no sequence homology with any aminotransferases, catalyze a non-stereospecific hydrogen transfer: the hydrogen transfer occurs on both faces of the planar intermediate. Crystallographical studies have shown that the catalytic base is situated on the re-face of the C-4' of the bound coenzyme in o-amino acid aminotransferase and branched chain L-amino acid aminotransferase, whereas the catalytic base is situated on the si-face in other aminotransferases (such as L-aspartate aminotransferase) catalyzing the si-face hydrogen transfer. Thus, we have clarified the stereospecificities of PLP enzymes in relation with the primary structures and three-dimensional structures of the enzymes. The characteristic stereospecificities of these enzymes for the hydrogen transfer suggest the convergent evolution of PLP enzymes.

• Nutritional Sciences
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• 제3권1호
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• pp.31-35
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• 2000

The purpose of this study was to compare the changes in PLP concentrations induced by regular, moderate, and abrupt, high-intensity exercise in the plasma and tissues of vitamin B6 deficient and normal rats. Forty-eight rats were fed either a vitamin B6 deficient (-B6) diet or a normal (+B6) diet for 5 weeks and were subdivided into 4 groups:non-exercise(NE) group: regular, moderate-intensity exercise (RME) group; abrupt, high-intensity exercise (AIE) group; abrupt, high-intensity exercise and recuperation(IRE) group. The RME group was exercised on treadmill ($10^{\circ}$, 0.5-0.8km/h) for 2 hours just before sacrifice at the end of 5th week on the diet and the IER group was recuperated for three days on the diet after being exercised like the AIE group. Pyridoxal 5 -phosphate(PLP) levels were compared in the plasma, liver and skeletal muscle of the rats. Plasma PLP concentration tended to decrease in -B6 rats and tended to increase in +B6 rats with AIE. Plasma PLP concentration in both +B6 rats with AIE and no change in both -B6 and +B6 rats with RME. Muscle PLP concentration decreased in +B6 rats, showed no change in -B6 rats with AIE. Muscle PLP concentrations in both +B6 and -B6 rats did not change with RME. Plasma PLP, liver PLP and muscle PLP concentration of IER returned to those of NE in both +B6 and -B6 rats. These results suggest that changes in PLP concentration in plasma, liver and muscle occur with exercise and are affected by exercise intensity and vitamin B6 status. These changes may be due to interorgan redistribution of PLP.