• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.354-359
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• 1997

Optimal cultivation conditions for the production of phenylalanine ammonia-lyase(PAL) from Rhodotorula aurantiaca K-505 were selected, and the kinetic parameters of the produced PAL were determined. The most suitable carbon and nitrogen sources were glucose and tryptone, respectively. The strain expressed PAL constituttively when using the optimized semi-complex media. High cell density culture could be critical for maximal production of PAl since the PAL ynthesis was growth associated. maximum PAL activity was observed at initial pH 6.0. although the ll growth was not markedly affected by temperature between 22 and 28$^{\circ}C$, the cells yielded the maximum PAL activity when cultivated at 22$^{\circ}C$. The maximum activity for deamination of L-phenylalnine to trans-cinnamic acid was observed around pH 8.8. The PAL activity gave the maximum at 45$^{\circ}C$, and greatly decreased at higher than 5$0^{\circ}C$. Activation energy({TEX}$E_{a}${/TEX}) calculated from Arrhenius equation was 6.28 kcal/mol in the range of 22$^{\circ}C$ to 4$0^{\circ}C$. A oolf plot showed that the enzyme reaction follows Michaelis-Menten equation, whose {TEX}$K_{M}${/TEX} and {TEX}$V_{max}${/TEX} values were 4.65$\times${TEX}$10^{-3}${/TEX} M and 0.89$\mu$ mol/mg-min respectively.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.954-958
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• 2009

Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH ($pH_{UC}$) and controlled-pH ($pH_C$) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the $pH_C$ operations, the highest PAL activities were obtained under $pH_C$ 7.5 strategy where cell mass ($OD_{600\;nm}$) and PAL activity was 1.3 and 1.8 fold higher than those of $pH_{UC}$, respectively. The maximum PAL activity reached 123 U/g. The $pH_C$ 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of L-phenylalanine.

• BMB Reports
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• v.31 no.1
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• pp.31-36
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• 1998

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), the first enzyme in the phenylpropanoid biosynthesis, catalyzes the elimination reaction of ammonium ion from L-phenylalanine. PAL was purified from the cytosolic fraction of Chinese cabbage (Brassica campestris ssp. napus var. pekinensis) through ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-200 chromatography, and Q-Sepharose chromatography. It consists of four identical subunits, the molecular mass of which was estimated to be about 38,000 daltons on SDS-PAGE. The optimal pH and temperature of the purified enzyme are 8~9 and $45^{\circ}C$, respectively. Its activity is greatly inhibited by $Zn^{2+}$ ion, and strongly activated by caffeic acid. The purified PAL has some different characteristics compared to those obtained with other PALs.

• Journal of Pharmaceutical Investigation
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• v.41 no.2
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• pp.95-102
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• 2011

An amphiphilic cationic branched methoxy poly (ethylene glycol)-branched polyethylenimine - poly(L-phenylalanine) (mPEG-bPEI-pPhe) block copolymer was successfully synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride of L-phenylalanine (Phe-NCA) with mPEG-bPEI for the preparation of more stable polyelectrolyte complex (PEC) included a hydrophobic interaction. mPEG-bPEI was firstly prepared by the coupling of mPEG and bPEI using hexamethylene diisocyanate (HMDI). The structural properties of mPEG-bPEI-pPhe copolymers were confirmed by $^1H$ NMR. The copolymers exhibited a self-assemble behavior in water above critical aggregate concentration (CAC) in the range of 0.01-0.14 g/L. The CAC of copolymers obviously depended on the hydrophobic block content in the copolymers (the value decreased with the increase of the pPhe block content). The cationic copolymers have the ability to form multi-interaction complex (MIC) with bovine serum albumin (BSA) and plasmid DNA through multi-interaction (electrostatic and hydrophobic interaction). The physicochemical characterization of the complex was carried out by the measurement of zeta potential and particle size. Their zeta-potentials were positive (approximately +10 mV) and their sizes decreased with increasing pPhe contents in the copolymers (PPF/BSA wt% ratio = 2). The complex showed good stability at high ionic strength. Therefore, mPEG-bPEI-pPhe block copolymer was considered as a potential material to enhance the stability of complex including biotherapuetic drugs.

• The Korean Journal of Zoology
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• v.33 no.1
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• pp.53-62
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• 1990

Fully grown amphibian oocytes undergo their maturation (germinal vesicle breakdown, GVBD) during in vitro follicle culture when they are stimulated with frog pituitary homogenate (FPH) or progesterone. Present experiments were designed to determine whether proteolytic enzymes are involved in the regulation of the matunation process. Treatment of a $\alpha$ -chymoiyypsin inhibitor, N a -tosyl-L-phenylalanine-chloromethyl-ketone(TP) to the oocytes exhibited a biphasic phenomenon, the induction of the maturation without added hormone at relatively low doses (0.001-1 $\mu$M) and inhibition of the hormone induced oocyte maturation at a high dose (100 $\mu$M). Treatment of a trypsin inhibitor, N a -tosyl-L-lysine-chloromethyl ketone(TLCK) to the oocytes did not induce the maturation, but rather suppressed the hormone induced oocyte maturation in a high dose(100 $\mu$ M). Treatment of exogenous iyypsin to the oocyte induced their maturation without added hormone in a dose dependent manner (0.001-1 $\mu$ M). The data presented here indicate that some proteolytic enzymes play a role in the regulation of the maturation(meiotic arrest or reinitiation) in amphibians.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.998-1004
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• 1995

This study was carried out in order to investigate the browning reaction of fish oil-amino acid model system at different temperatures and watger activities. The 23 amino acids, induced during dehydration in the presence of oil and avicel(5 to $45^{\circ}C$), Aw 0.33 to 0.95, were resulted in three types of browning patterns : Type I showed high browning rates at Aw 0.33, 0.95 than at Aw 0.52, 0.75(phenylalanine, trans-4-hydroxy-L-proline, methionine, valine). Type II showed high browning rates decreased with increasing water activity(poline, leucine, isoleucine, arginine). Type III showed high browning rates at Aw 0.52, 0.75 than at Aw 0.33, 0.95(tryptophan, cystein, threonine, lysine). The temperature effect on the browning development of the four most active amino acids : phenylalanine, valine, trnas-4-hydroxy-proline and methionine are shown to represent the 23 amino acids. Above $25^{\circ}C$ the browning rate began to increase. Activation energy of the amino acids-fish oil was 8 to 40kcal/mole, and $Q_{10}$ were 2 to 10.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.3
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• pp.255-259
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• 1996

A study was carried out to investigate the action of central L-pheylalanine (Phe) and L-tyrosine (Tyr) on food intake of the chicken. In the first trial, Phe ($200{\mu}g/10{\mu}l$) or saline was acutely administered into the right lateral ventricle (i.c.v.) of chickens (5 birds per each group). Birds (4 birds per each group) were administered with the i.c.v. Tyr ($200{\mu}g/10{\mu}l$) or saline in the second trial. The brains of the birds were removed for catecholamine assy 30 min postadministration. Catecholamine concentrations were measured at specific sites of the brain (LH: lateral hypothalamus, PVN: paraventricular nucleus, and VMH: ventromedial hypothalamus). No significant effect of amino acids on the concentration of norepinephrine of brain sites investigated was detected. Food intake and rectal body temperature were also monitored for 6 h after central administrations of Phe, Tyr or saline (5 birds per each group). Both Phe and Tyr, up to $1mg/10{\mu}l$, failed to modulate food intake or rectal body temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.1
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• pp.10-17
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• 1987

In order to investigate the effects of growth regulators on the formation of capsaicinoids in callus of Capsicum annuum L. tissues were cultured in the Linsmaier and Skoog RM 1964 medium containing various growth regulators. Production of capsaicinoids during culture was monitored by gas chromatography. In the presence of $10^{-6}M$ of 2,4-D and kinetin in the medium, $1182{\mu}g$ of capsaicinoids were formed per 100g dry wt. of tissue, of which was greater than with any of three other growth regulators. IAA, NAA, and kinetin of same concentrations had 65%, 38%, 68% effect of 2.4-D in capsaicinoids formation, respectively. Production of capsaicinoids increased gradually in the presence of 2,4-B as culture period was proceeded. Of phenylpropanoids formed, cinnamic acid and coumaric acid were not significantly different in their levels, although growth regulators were varied. On the other hand, caffeic acid and ferulic acid formation were highest in the presence of 2,4-D. Effects of kinetin and IAA were about 70 percent of that of 2,4-D, whereas NAA had only about 30 percent effect. Phenylalanine ammonia-lyase activity in cultured tissue was increased during the periods; 52, 81, and 209 n moles of cinnamic acid per g fresh wt. were formed after 5, 15, and 25 days of culture, respectively.

• Journal of the Korean Chemical Society
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• v.14 no.2
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• pp.161-168
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• 1970

In order to obtain the more effective evidence, supporting the hypothesis which have been previously described by former report that pepsin (EC 3.4. 4.1) forms a hydrophobic bond with the nonpolar side chain of its substrate, the inhibitory effect of carboxylic acids(from formic acid to iso-butyric acid) on the activity of pepsin to the synthetic dipeptide, N-Carbobenzoxy-L-glutamyl-L-tyrosine, was discussed. The kinetic study showed that the inhibition by carboxylic acids was competitive. The Kidecreased with increasing size of the inhibitor molecule. The $-{\Delta}F^{\circ}$increased linearly with increasing number of carbon atoms in the hydrocarbon chain of the inhibitor. It was confirmed that the hydrophobic bond between more than one side chain of amino acid residues(phenylalanine) in the binding region of the active center of pepsin and the side chain of amino acid residues in the substrate was formed as the first step of its enzymic mechanism. The inhibitory effect of carboxylic acids was due to the competition of the hydrocarbon group of the carboxylic acids with the side chain of the substrate for the hydrophobic binding site(the side chain of phenylalanine) of the pepsin.

• YAKHAK HOEJI
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• v.30 no.1
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• pp.47-50
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• 1986

The enantiomers of five amino acids (alanine, valine, threonine, leucine and phenylalanine) could be separated by gas chromatography with optically active (S)-5-isopropyll-$N^3$-phenyl-2-thiohydantoinic stationary phase, which prepared from L-valine and phenylisothiocyanate. Gas chromatographic separations on methylesterificated and N-trifluoroacetylated amino acids have been conducted in isothermal at several column temperatures (180~190, 200, $210^{\circ}C$). The separation factors were 1.29 (alanine, $190^{\circ}C$), 1.35 (valine, $190^{\circ}C$), 1.33 (threonine, $190^{\circ}C$), 1.17 (leucine, $190^{\circ}C$) and 1.05 (phenylalanine, $190^{\circ}C$) and D-isomers eluted prior to L-isomers in every instance. The result of this experiment shows that this stationary phase can be used for the separation of the other amino acids enantiomers.