• Journal of Nutrition and Health
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• 제27권9호
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• pp.930-939
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• 1994

Vitamin B-6 nutrition has been shown to be inadequate in many population groups including pregnant and lactating women, and in infants. Vitamin B-6 intake was measured in 98 pregnant mothers and a total of 172 cord blood samples of their and other new born infants were analyzed for erythrocyte alanine aminotransferase(EALAT) activities with or without the addition of pyridoxal-5-phosphate to assess vitamin B-6 status of the infants. The average daily vitamin B-6 intake of the pregnant mothers was 1.79mg$\pm$0.88(81.4% of the Recommended Dietary Allowances ; RDA) and vitamin B-6 to protein intake ration was 0.017mg vitamin B-6/g protein. Thirty-eight percent of the pregnant women consumed diets which provided less than the RDA for vitamin B-6 during pregnancy. Seventy-two percent of the dietary pyridoxine intake was provided by the plant food source whose bioavailability was reported to be lower when compared to that of the animal food. The average activity coefficient(AC) values of the cord blood EALAT was 1.41$\pm$0.11, and 32% of the blood samples had EALATAC values greater than 1.25, suggesting that vitamin B-6 status of the newborns might be less than adequate.

• Journal of Microbiology and Biotechnology
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• 제17권9호
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• pp.1579-1584
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• 2007

5-Aminolevulinate (ALA) synthase (E.C. 2.3.1.37), which mediates the pyridoxal phosphate-dependent condensation of glycine and succinyl-CoA, encoded by the Rhodobacter sphaeroides hemA gene, enables Escherichia coli strains to produce ALA at a low level. To study the effect of the enhanced C4 metabolism of E. coli on ALA biosynthesis, NADP-dependent malic enzyme (maeB, E.C. 1.1.1.40) was coexpressed with ALA synthase in E. coli. The concentration of ALA was two times greater in cells coexpressing maeB and hemA than in cells expressing hemA alone under anaerobic conditions with medium containing glucose and glycine. Enhanced ALA synthase activity via coupled expression of hemA and maeB may lead to metabolic engineering of E. coli capable of large-scale ALA production.

• Clinical and Experimental Pediatrics
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• 제58권11호
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• pp.407-414
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• 2015

Early-onset epileptic encephalopathies are one of the most severe early onset epilepsies that can lead to progressive psychomotor impairment. These syndromes result from identifiable primary causes, such as structural, neurodegenerative, metabolic, or genetic defects, and an increasing number of novel genetic causes continue to be uncovered. A typical diagnostic approach includes documentation of anamnesis, determination of seizure semiology, electroencephalography, and neuroimaging. If primary biochemical investigations exclude precipitating conditions, a trial with the administration of a vitaminic compound (pyridoxine, pyridoxal-5-phosphate, or folinic acid) can then be initiated regardless of presumptive seizure causes. Patients with unclear etiologies should be considered for a further workup, which should include an evaluation for inherited metabolic defects and genetic analyses. Targeted next-generation sequencing panels showed a high diagnostic yield in patients with epileptic encephalopathy. Mutations associated with the emergence of epileptic encephalopathies can be identified in a targeted fashion by sequencing the most likely candidate genes. Next-generation sequencing technologies offer hope to a large number of patients with cryptogenic encephalopathies and will eventually lead to new therapeutic strategies and more favorable long-term outcomes.

• Journal of Nutrition and Health
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• 제43권3호
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• pp.315-323
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• 2010

The purpose of this study was to establish the selection of indicators for estimating and factors affecting the requirement of vitamin B6. There has been a need to establish the human requirements of vitamin $B_6$ since vitamin $B_6$ is thought to be involved in more than one hundred biochemical reactions as a coenzyme in the metabolism of amino acids, glucose, and lipid, and the synthesis of neurotransmitters. For the review of the literature, this study included from early findings of the sixties to studies of 2009. This study suggests that plasma pyridoxal 5' phosphate (PLP) is the best single indicator of vitamin $B_6$ status for the healthy but not for the non-healthy. Erythrocyte aspartate aminotransferase and alanine aminotransferase activation by PLP as an indirect measure and urinary 4-pyridoxic acid excretion as a direct measure are useful as supporting indicators. Bioavailability, nutrient interaction, physiological need, and chronic diseases may increase the requirement for vitamin $B_6$. However, these effects can not be quantified due to insufficient evidences.

• 미생물학회지
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• 제35권2호
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• pp.133-138
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• 1999

Bacillus subtilis ED 213의 cytidine deaminase 의 활성부위에 존재하는 필수 아미노산잔기를 화학수식 방법으로 측정하였다. 본 효소는 1mM o-phenanthroline 에 의하여 효소활성이 43% 저해되어 효소활성 발현에 Fe\sup 2+\가 요구된다고 추정되며, 1mM ethylenediaminetetraacetic acid 에 의해서는 효소활성이 오히려 28% 정도 촉진되었다. 본 효소는 1mM N-bromosuccinimide, 1mM chloramine-T 와 1mM $\rho$-chloromercuribenzoic acid에 의하여 100% 저해되었으며, 그의 저해 양상은 경쟁적 저해 양상을 나타내었다. 본 효소의 효소활성은 1mM pyridoxal-5-phosphate 에 의항 36% 저해되었으며, 1mM 1ethyl-3-carbodiamide 와 1mM glycine methylester에 의해 저해된 효소활성이 5mM cysteine에 의해 완전히 회복되었다. 이상의 결과로부터 Bacillus subtilis ED 213 cytidine deaminase의 활성부위에는 tyrosine, methionine, cysteine 과 serine 잔기가 관여할 뿐만 아니라 lysine 과 glycine 도 효소활성에 관여하는 것으로 추정된다.

• Journal of Applied Biological Chemistry
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• 제53권3호
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• pp.132-138
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• 2010

B. pseudomycoides로 부터 alanine racemase로 추정되는 유전자를 분리한 다음 6xHistidine 이 결합된 pET-21 운반체를 이용하여 E. coli BL21(DE3)에서 발현시키고 생화학 특성을 조사하였다. 재조합된 alanine racemase는 affinity chromatography를 이용하여 분리하였으며 SDS-PAGE 분석에서 약 46 kDa의 단일밴드를 나타내었다. 분리된 효소는 여러 아미노산 중에서 L-alanine에 대하여 가장 높은 활성도를 보이고 D-alanine에 대하여 두번째로 높은 활성도를 보였다. 따라서 분리된 효소는 alanine racemase로 판단되었다. 분리된 효소는 D-cysteine에 하여 상당히 저해가 되었다. 효소의 최적 활성도는 pH 9.0 근처에서 관찰되었고 산성의 조건보다는 알칼리의 조건에서 보다 안정하였다. 보효소인 PLP 0.3mM의 첨가에 의해 효소의 활성도는 약 70% 가량 증대되었다.

• BMB Reports
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• 제32권5호
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• pp.480-485
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• 1999

Tyrosine phenol-lyase of thermophilic Symbiobacterium sp. SC-1, which is obligately and symbiotically dependent on thermophilic Bacillus sp. SK-1, was purified and characterized. The enzyme is composed of four identical subunits and contains approximately 1 mol of pyridoxal 5'-phosphate (PLP) per mol subunit as a cofactor. The enzyme showed absorption maxima at 330 and 420 nm, and lost this absorption profile by treatment with phenylhydrazine. The apparent dissociation constsnt, $K'_D$, for PLP was determined with the apoenzyme to be about $1.2\;{\mu}M$. The isoelectric point was 4.9. The optimal temperature and pH for the $\alpha,\beta$-elimination of L-tyrosine were found to be $80^{\circ}C$ and pH 8.0, respectively. The substrate specificity of the enzyme was very broad: L-amino acids including L-tyrosine, 3,4-dihydroxyphenyl-L-alanine (L-DOPA), L-cysteine, L-serine, S-methyl-L-cysteine, $\beta$-chloro-L-alanine, and S-(o-nitrophenyl)-L-cysteine all served as substrates. D-Tyrosine and D-serine were also decomposed into pyruvic acid and ammonia at rates of 7% and 31% relative to their corresponding L-enantiomers, respectively. D-Alanine, which was inert as a substrate in a, $\beta$-elimination, was the only D-amino acid racemized by the enzyme. The $K_m$ values for L-tyrosine, L-DOPA, S-(o-nitrophenyl)-L-cysteine, $\beta$-chloro-L-alanine, and S-methyl-L-cysteine were 0.19, 9.9, 0.36, 12, and 5.5 mM, respectively.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.505.2-506
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• 1986

L-Azetidine-2-carboxylic acid (A-2-C), a four-membered cyclic imino acid has been identified in certain plants, and the microorganism Actinoplanes ferrugineus. The imino acid A-2-C has a physiological significance as an antgaonist of proline during peptide synthesis. The biosynthetic mechanism for the formation of A-2-C has not been studied in any detail. By using various amino acids such as methionine and S-adenosyl-L-methionine labeled with deuterium or carbon-14, the details of the biosynthetic pathway and a possible mechanism for the formation of L-A-2-C in .4. ferrugineus have been unravelled, Both in vivo and in vitro experimental results suggest the biosynthesis of L-A-2-C is mediated by a confactor containing a carbonyl group, probably pyridoxal Phosphate. S-Adenosyl-L-methionine, which seems to be the direct biosynthetic substrate, has undergone a f-displacement by an ${\alpha}$-amino group of the amino acid portion of the substrate S-adenosyl-L-methionine potentially via a vinylglycine intermediate. The overall stereochemical events at the ${\beta}$-carbon of the substrate have been shown to inversion of configuration. The overall stereochemical events at the -position of the sub- strate have also been shown to occur with inversion of configuration. The ${\beta}$, ${\gamma}$-elimination reaction of the substrate seems to follow a cisoidal-type mechanism and the addition portion of the reaction a transoidal-type mechanism . The assignment of the proton NMR of A-2-C has been deduced by apply- ing NOE difference experiments, Gd(III) line-broadening experiments and 2D-NOESY experiments of regio-and stereospecificially deuterated A-2-C's.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1586-1592
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• 2016

Klebsiella pneumoniae is a gram-negative, non-motile, rod-shaped, and encapsulated bacterium in the normal flora of the intestines, mouth, skin, and food, and has decarboxylation activity, which results in generation of diamines (cadaverine, agmatine, and putrescine). However, there is no specific information on the exact mechanism of decarboxylation in K. pnuemoniae. Specifically lysine decarboxylases that generate cadaverine with a wide range of applications has not been shown. Therefore, we performed a functional study of lysine decarboxylases. Enzymatic characteristics such as optimal pH, temperature, and substrates were examined by overexpressing and purifying CadA and LdcC. CadA and LdcC from K. pneumoniae had a preference for L-lysine, and an optimal reaction temperature of 37℃ and an optimal pH of 7. Although the activity of purified CadA from K. pneumoniae was lower than that of CadA from E. coli, the activity of K. pneumoniae CadA in whole cell bioconversion was comparable to that of E. coli CadA, resulting in 90% lysine conversion to cadaverine with pyridoxal 5'-phosphate L-lysine.

• Journal of Microbiology and Biotechnology
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• 제18권6호
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• pp.1136-1140
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• 2008

The Rhodopseudomonas palustris KUGB306 hemA gene codes for 5-aminolevulinic acid (ALA) synthase. This enzyme catalyzes the condensation of glycine and succinyl-CoA to yield ALA in the presence of the cofactor pyridoxal 5'-phosphate. The R. palustris KUGB306 hemA gene in the pGEX-KG vector system was transformed into Escherichia coli BL21. The effects of physiological factors on the extracellular production of ALA by the recombinant E. coli were studied. Terrific Broth (TB) medium resulted in significantly higher cell growth and ALA production than did Luria-Bertani (LB) medium. ALA production was significantly enhanced by the addition of succinate together with glycine in the medium. Maximal ALA production (2.5 g/l) was observed upon the addition of D-glucose as an ALA dehydratase inhibitor in the late-log culture phase. Based on the results obtained from the shake-flask cultures, fermentation was carried out using the recombinant E. coli in TB medium, with the initial addition of 90 mM glycine and 120 mM succinate, and the addition of 45 mM D-glucose in the late-log phase. The extracellular production of ALA was also influenced by the pH of the culture broth. We maintained a pH of 6.5 in the fermenter throughout the culture process, achieving the maximal levels of extracellular ALA production (5.15 g/l, 39.3 mM).