• Biomolecules & Therapeutics
• /
• 제17권1호
• /
• pp.104-110
• /
• 2009

Phenylketonuria (PKU) is an inherited metabolic disorder caused by mutations in the phenylalanine catabolic enzyme, phenylalanine hydroxylase (PAH). The use of phenylalanine ammonia-lase (PAL) by oral and parenteral routes as a therapeutic drug for PKU has been severely limited due to inactivation by intestinal proteolysis and immune reactions. PEGylation was applied to PAL to reduce the degrees of antigenicity and proteolytic inactivation. Kinetic experiments with native PAL and pegylated PALs were performed, and pH stability, temperature stability, and protease susceptibility were evaluated. Enzyme linked immunosorbent assay (ELISA) was carried out to measure the immune complex between pegylated PALs and antiserum that had been extracted from a PAL-immunized mouse. Pegylated PAL, especially branched pegylated PAL (10 kDa, 1:32), was more active for phenylalanine and more stable in pancreatic proteases than native PAL. Native PAL was optimal at pH 8.5, corresponding to the average pH range of the small intestine; the same finding was noted for pegylated PALs. All linear and branched pegylated PALs had low reactivity with mouse antiserum, especially the 1:16 formulation with linear 5-kDa PEG and the 1:32 formulation with branched 10-kDa PEG. Therefore, we suggest the 1:32 formulation with branched 10-kDa PEG as the most promising formulation for enzyme replacement therapy.

• 한국식품영양학회지
• /
• 제9권4호
• /
• pp.430-433
• /
• 1996

딸기의 2차대사에 관여하는 phenylalanine ammonia-lyase는 풍미나 색소, 향기 등에 큰 영향을 미치며 숙도 측정지표로 여겨진다. phenylalanine ammonia-lyase는 숙성 전단계에 걸쳐 활성을 나타내기는 하나 완숙기와 과숙기에 그 활성이 뚜렷이 증가하였다. 이는 딸기의 숙성과 더불어 de novo 합성이 되기 때문으로 보인다. 분자량은 겔 크로마토그래피로 260,000으로 나타났다.

• Food Science and Biotechnology
• /
• 제18권2호
• /
• pp.494-499
• /
• 2009

To improve phenylalanine ammonia lyase (E.C.4.3.1.5-PAL) activity in recombinant Escherichia coli, Some approaches for improving phenylalanine ammonia lyase (PAL) activity in recombinant E. coli were developed following preliminary studies by means of response surface method. The results shown that permeabilization with combination of Triton X-100, cetyl trimethyl ammonium bromide (CTAB), and acetone enriched cellular recombinant PAL activity significantly, which improved over 10-fold as compared with the control (untreat cell), as high as 181.37 U/g. The optimum values for the tested variables were Triton X-100 0.108 g/L, CTAB 0.15 g/L, and acetone 45.2%(v/v). Furthermore, a second-order model equation was suggested and then validated experimentally. It was indicated that addition of surfactants and organic solvents made the cells more permeable and therefore allowed easier access of the substrate to the enzyme and excretion of the product, which increased the rate of transport of L-phenylalanine and trans-cinnamic acids. These improved methods of PAL activity enrichment could serve as a rich enzyme source, especially in the biosynthesis of L-phenylalanine.

• 한국자원식물학회지
• /
• 제23권6호
• /
• pp.535-540
• /
• 2010

Phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid biosynthesis pathway, is activated by a number of developmental and environmental cues. The coding region of the NtPAL4 gene was 2,154 bp in length, and its deduced protein was composed of 717 amino acids. Sequence analysis of NtPAL4 cDNA from tobacco (Nicotiana tabacum L.) revealed high structural similarity to PAL genes of other plant species. The NtPAL4 gene exists as a single copy in the tobacco plant, and its transcripts were strongly expressed in flowers and leaves. NtPAL4 expression was significantly induced in response to NaCl, mannitol, and cold treatments, but it was not induced by abscisic acid (ABA). NtPAL4 expression decreased gradually after treatment with ABA and $H_2O_2$; however, NtPAL4 transcripts accumulated after treatment with methyl viologen (MV). Our results suggest that the NtPAL4 gene may function in response to abiotic stresses.

• Plant Biotechnology Reports
• /
• 제5권4호
• /
• pp.301-308
• /
• 2011

This study tested the relative and combined efficacy of ShPx2 and ShPAL transgenes by comparing Nicotiana tabacum hybrids with enhanced levels of $_L$-phenylalanine ammonia lyase (PAL) activity and cationic peroxidase (Prx) activity with transgenic parental lines that overexpress either transgene. The PAL/Prx hybrids expressed both transgenes driven by the 35S CaMV promoter, and leaf PAL and Prx enzyme activities were similar to those of the relevant transgenic parent and seven- to tenfold higher than nontransgenic controls. Lignin levels in the PAL/Prx hybrids were higher than the PAL parent and nontransgenic controls, but not significantly higher than the Prx parent. All transgenic plants showed increased resistance to the necrotrophs Phytophthora parasitica pv. nicotianae and Cercospora nicotianae compared to nontransgenic controls, with a preponderance of smaller lesion categories produced in Prx-expressing lines. However, the PAL/Prx hybrids showed no significant increase in resistance to either pathogen relative to the Prx parental line. These data indicate that, in tobacco, the PAL and Prx transgenes do not act additively in disease resistance. Stacking with Prx did not prevent a visible growth inhibition from PAL overexpression. Practical use of ShPAL will likely require more sophisticated developmental control, and we conclude that ShPx2 is a preferred candidate for development as a resistance transgene.

• 생명과학회지
• /
• 제15권2호
• /
• pp.298-303
• /
• 2005

포도 '거봉'의 착색을 조장하기 위해 적절한 ABA의 처리시기와 처리 횟수를 알아보기 위하여 본 실험을 수행한 결과 다음과 같은 결과를 얻었다. PAL 효소의 활성은 변색기 처리구와 변색기 10일 후 처리구에서 활성이 높은 것으로 나타났으며, 변색기 10일후 처리구가 변색기 처리구보다 약간 더 높은 효소 활성을 나타냈다. 안토시아닌 함량은 각 처리구 공히 생육기간 동안 계속 증가하는 경향을 보였고, 모든 ABA 처리구는 무처리구에 비해 훨씬 높은 안토시아닌 함량을 나타내었으며, 변색기 10일후 처리구에서 가장 높은 안토시아닌 함량을 나타내었다. 가용성당 함량에 있어서 과당과 포도당만이 검출되었으며, 처리구간에 함량의 차가 그다지 크지 않았다. 처리 횟수에 있어서 PAL 효소의 활성은 각 처리구 공히 증가하다가 감소하는 경향을 보였으며, 2회 처리구는 변색기 10일후의 2회째 처리 이후에도 급속한 PAL 효소 활성 증가가 이어져 최종수확기에서도 비교적 상당히 높은 효소 활성을 보였다. 변색기와 변색기 10일 후의 2회 처리구에서 안토시아닌 함량 증가가 가장 높아 최종수확기에 가서는 무처리구에 비해 5배 이상, 1회 처리구에 비해서는 2배정도 많았다. 1회 및 2회 ABA 처리구 모두 과당과 포도당 함량 공히 무처리구에 비해 약간 높은 경향을 나타냈지만 그다지 큰 차이는 없었다.

• Preventive Nutrition and Food Science
• /
• 제2권4호
• /
• pp.354-359
• /
• 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.

• 한국균학회지
• /
• 제39권3호
• /
• pp.205-212
• /
• 2011

진균의 phenylalanine ammonia-lyase(PAL)와 식물의 PAL간 그리고 PAL과 histidine ammonia-lyase (HAL)간의 구조적 특성 관계에 대한 이해를 얻기 위해 옥수수병원균인 깜부기균(Ustilago maydis)의 PAL에 대한 면역학적 분석을 수행하였다. 진균의 PAL 항체와 식물의 PAL 항체를 이용하여 분석하였을 때 실험한 모든 종의 PAL 간에 교차반응이 나타났다. 알팔파 PAL 항체와 포플라 PAL 항체 모두 식물 PAL은 강하게 인식하였으나 진균의 PAL은 약하게 인식하였다. U. maydis PAL은 Rhodotorula glutinis 효모의 PAL만 약하게 인식하였다. U. maydis PAL은 식물의 PAL에 대해서 낮은 친화성을 보였으나 Pseudomonas 세균의 HAL에 대해서는 강한친화성을 보였다. 2종의 식물 PAL 항체들 또한 Pseudomonas 세균의 HAL에 대해 강한 친화성을 보였다. 진균과 식물의 PAL 항체는 PAL 효소의 활성 저해를 나타냈으며 세균의 HAL 효소의 활성에 대해서도 중도적 저해를 나타냈다. 세균의 HAL 항체는 식물과 효모와 Ustilago PAL 중에 Ustilago PAL 활성만 저해하였다. 식물의 PAL과 진균의 PAL 모두 효모의 PAL 활성은 저해하지 못했다. 본 연구는 PAL과 HAL간에 면역학적 관계가 있음을 처음으로 보고한다.

• Food Science and Biotechnology
• /
• 제18권4호
• /
• pp.954-958
• /
• 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.

• 한국환경과학회지
• /
• 제14권12호
• /
• pp.1093-1102
• /
• 2005

Effects of abscisic acid(ABA) and temperature on the anthocyanin accumulation and phenylalanine ammonia Iyase(PAL) activity were investigated in seedlings of Arabidopsis thaliana. In time course study, exogenous application of ABA $(50-1000\;{\mu}M)$ led to a noticeable increase in anthocyanin pigments which persisted over the following 5 days. Anthocyanins increased in concert with the chlorophyll loss. The activity of PAL, a key enzyme in the phenylpropanoid pathway, increased on exposure to ABA and reached maximum on the 4th day, This result shows that anthocyanin synthesis and PAL activity have a close physiological relationships. In the effects of temperatures ($10^{\circ}C,\;17^{\circ}C,\;25^{\circ}C$and $30^{\circ}C$) on anthocyanin accumulation and PAL activity in seedlings, a moderate-low temperatures ($17^{\circ}C$) enhanced both anthocyanin content and PAL activity, whereas elevated temperatures ($30^{\circ}C$) showed low levels of anthocyanin and PAL activity, suggesting a correlation between temperature-induced anthocyanin synthesis and the accumulation of PAL mRNA. Simultaneous application of ABA with temperatures Induced higher anthocyanin synthesis and PAL activity in seedlings than ABA or temperature stress alone. Moderate-low temperature with ABA exposure elicited the maximal induction of anthocyanin synthesis and PAL activity. Therefore, ABA treatment significantly increased thermotolerance in .A. thalinan seedlings. Ethephon and ABA showed similar mode of action in physiological effects on anthocyanin accumulation and PAL activity. Our data support that anthocyanins may be protective in preventing damage caused by environmental stresses and play an important role in the acquisition of freezing tolerance.