• BMB Reports
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• v.33 no.1
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• pp.82-88
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• 2000

A homologous gene to alanine racemase was cloned from a hyperthermophilic bacterium, Aquifex pyrophilus. The cloned gene encodes a protein of 341 amino acids, which has a significant homology to alanine racemase of Bacillus stearothermophilus, Lactobacillus brevis, and E. coli. When the gene was expressed in Escherichia coli, it produced a 40 kDa protein. The purified protein contains one mole pyridoxal 5-phosphate per one mole of protein, which is essential for catalytic activity of alanine racemase. The purified protein catalyzed racemization of L-alanine to D-alanine, or vice versa, indicating that the cloned gene encoded alanine racemase. It also showed significant racemization activity against L-serine and ${\alpha}-aminobutylic$ acid. The A. pyrophilus alanine racemase showed strong thermostability, and it maintained catalytic activity in the presence of organic solvents.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.132-138
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• 2010

A gene encoding a putative alanine racemase in B. pseudomycoides was cloned and expressed in Escherichia coli BL21(DE3) using a pET-21 vector harbouring 6xHistidine tag. Affinity purification of the recombinant alanine racemase with a nickel resin resulted in one band by SDS-PAGE analysis. The purified enzyme showed a molecular weight of 46 kDa. The enzyme was the most active toward L-alanine and secondly D-alanine, implying that the enzyme is an alanine racemase. D-cysteine significantly inhibited the enzyme activity and also L-cysteine to a lesser extent. The enzyme was considerably activated by addition of pyridoxal-5'-phosphate (PLP), showing that 73% increase in activity was observed at 0.3 mM, compared to control. The enzyme was the most active at pH 9.0 and more stable at alkaline pHs than acidic pHs.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.130-131
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• 2014

자동용접용 솔리드와이어를 위한 치환동도금층 밀착력 향상을 위해 착화제로 Alanine을 사용하였다. 테이프 시험결과 Alanine 첨가에 따라 밀착력이 현저히 증가하였다. 또한 도금층내에 혼입되는 H와 Fe 분석결과 Alanine을 첨가하지 않았을 때 도금층 전체 영역에서 H와 Fe의 검출강도가 높게 나타났으나, Alanine 10g/l추가시 도금층내에서 미량 검출되었다.

• Journal of Applied Biological Chemistry
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• v.53 no.4
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• pp.195-201
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• 2010

A gene encoding an alanine racemase in B. pseudomycoides was cloned and one (Cys316) or both of two cysteines (Cys316 and Cys365) was (were) substituted with alanine. The cysteine (-) alanine racemases were expressed in E. coli BL21 (DE3) using a pET-21 vector. The expressed enzymes were purified through affinity chromatography using 6xHis ligand. The purified enzymes all showed major one bands by SDS-PAGE analysis, corresponding to 46 kDa. The cysteine (-) alanine racemases as well as the wild type enzyme showed alanine racemase activities, indicating that the enzyme is an alanine racemase and the cysteines in the enzyme may not be involved in the catalysis and/or substrate binding. Thermal stabilities of Cys (-) alanine racemases decreased considerably and half-lives were 26 (wild type), 21 (C316A) and 18 min (C316-365A), respectively at $60^{\circ}C$ pH 8.0, suggesting that cysteine is considerably contributive to the thermal stability of the alanine racemase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.2
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• pp.314-319
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• 2001

In the present study, effects of $\beta$-alanine, a known taurine antagonist for its structural similarity, on the adaptive regulation and kinetic behavior of the taurine transporter were investigated in the HT-29, human colon carcinoma cell line. Pretreatment of the cell with $\beta$-alanine(10mM) for varying periods from 3 to 30 hrs significantly reduced the taurine uptake compared to the value for control cells. This decrease in the taurine transporter activity was dependent on the incubation time with $\beta$-alanine, and the maximal down-regulation of the transporter activity was observed in cells pretreated with $\beta$-alanine for 24 hrs (25% of the control value, p<0.01). The taurine transporter appears to bind exclusively with $\beta$-alanine in the HT-29 cells since the same concentration of $\alpha$-alanine added in the culture medium for 24 hrs did not influence the taurine uptake. Kinetic analyses of the taurine transporter activity was performed in the HT-29 cell line with varying taurine concentration (5~60$\mu$M) in the uptake medium. Active taurine uptake was significantly lower in $\beta$-alanine pretreated cells compared to the value for control cells in the range of taurine concentration used in the experiment (p<0.001). The cells pretreated with $\beta$-alanine showed a 50% lower maximal velocity (Vmax, 1.7$\pm$2.0 nmole.mg $protein^{-1}$.$30min^{-1}$), and a 99% higher Michaelis constant (Km, 40.3$\pm$7.6$\mu$M) than the control values (3.3$\pm$1.9 nmole.mg $protein^{-1}$.$30min^{-1}$, and 20.3$\pm$2.1$\mu$M, respectively). These results on kinetic data suggest that $\beta$-alanine induced down-regulation of the taurine transporter activity was associated with decreases in both maximal velocity and affinity of the transporter.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.1
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• pp.93-99
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• 1999

The purpose of this study was to investigate the antioxidant and synergistic effects upon different concentrations(0.02, 0.1, l%) of histidine and alanine in soybean oil during incubation at 6$0^{\circ}C$. Acid value(AV), peroxide value (POV) and thiobarbituric acid(TBA) value of each oil was monitored. Histidine and alanine showed antioxidative effects in all concentrations. In the case of the incubating antioxidative effect of histidine was lower than that of TBHQ. That of alanine was considerably higher than that of $\alpha$-tocopherol, but was lower than that of histidine. Synergistic effects among histidine, alanine and some food antioxidants were shown to exist available in all substrates and the best effect was shown in substrate added compound of histidine and $\alpha$-tocopherol.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.519-533
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• 2010

Activity oefficients and solubilities of L-Alanine in aqueous solutions containing each of four electrolytes(NaCl, KCl, $NaNO_3$ and $KNO_3$) were measured at 298.15 K. The measurements of activity coefficients were carried out in the electrochemical cell coupled with two ion-selective electrodes(cation and anion), and the solubilities were measured by the gravimetric analysis of saturated solutions in equilibrium with the solid phase of L-alanine. To model the activity coefficients and solubilities of amino acid in the amino acid/electrolyte aqueous solutions, thermodynamic relations of the residual Helmholtz free energy in the amino acid/electrolyte aqueous solutions were developed based on the perturbed-chain statistical associating fluid theory(PC-SAFT) combined with the primitive mean spherical approximation(primitive-MSA). In the present model, it is assumed that the zwitterions of L-alanine are associated with each other and cross-associated with water molecules, and also cross-associated with the cation and anion dissociated from an electrolyte(inorganic salt). The activity coefficients and solubilities of L-Alanine calculated from the theoretical model proposed in this work are found to be well agreeable with experimental data.

• Progress in Medical Physics
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• v.4 no.1
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• pp.41-53
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• 1993

The electron spin resonanec of sigle crystals of L-alanine have been observed at T=300K, 100K and analyzed for different orieantations of the crystal in the magnetic field and at microwave frequency X-band. The stable free radical profuced by the irradiation is proved to be of the form CH$_3$CHR, where R is a group which has no nuclei with detectable coupling A notable dependence on temperature of the absorption was observed in the range from 1100K to 2l0K. It was concluded that the reorietation of the methy group of the radical H$_3$CCHR is quenched at low temperature.

• Nutritional Sciences
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• v.5 no.1
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• pp.9-12
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• 2002

This study was conducted to investigate the effects of oral supplementation of alanine and glutamine on alcohol metabolism. The subjects were 70 male ICR mice weighing 25-30 g. The animals were raised on standard rations artier weaning. After 24 hours of fasting, all the animals were given a peritoneal injection of 20% alcohol. Then, they were randomly divided into two groups: control and experimental. Fifteen minutes after the injection of alcohol, the mice in the experimental group wer given an oral solution of alanine(5 mM, 2 g/kg B. W) and glutamine (5 mM, 2g/kg B.W). The concentration of alcohol in the blood was measured in all the mice 20 minutes after they received the alochol, and the measurements continued every 20 minutes up to 140 minutes. The experimental group sustained lower blood alcohol levels at every 20 minute time interval compared to the control group, showing that oral supplementation of alanine and glutamine increases the rate of alcohol metabolism. Furthermore, the total amount of alcohol remaining in the blood, determined by using the Area Under the Curve (AUG) method, was lower in the group supplemented with alanine and glutamine, However, the effectiveness of alanine and glutamine in increasing the rate of alcohol metabolism, compared to the control group, diminished with time throughout the experiment. In conclusion, alanine and glutamine supplementation appears to promote alcohol metabolism shorthy after alcohol intake.

• Radiation Oncology Journal
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• v.7 no.1
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• pp.85-92
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• 1989

Dosimerty based on electron spin resonance (ESR) analysis of radiation induced free radicals in amino acids is relevant to biological dosimetry applications. Alanine detectors are without walls and are tissue equivalent. Therefore, alanine ESR dosimetry looks promising for use in the therapy level. The dose range of the alanine/ESR dosimetry system can be extended down to 1 Gy. In water phantom the absorbed dose of electrons generated by a medical linear accelerator of different initial energies $(6\~21MeV)$ and therapeutic dose levels (1~60 Gy) was measured. Furthermore, depth dose measurements carried out with alanine dosimeters were compared with ionization chamber measurements. As the results, the measured absorbed doses for shallow depth of initial electron energies above 15 MeV were higher by$2\~5\%$ than those calculated by nominal energy $C_E$ factors. This seems to be caused by low energy scattered beams generated from the scattering foil and electron cones of beam projecting device in medical linear accelerator.