• 대한화학회지
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• 제39권6호
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• pp.459-465
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• 1995

효모 acetolactate synthase를 분리 정제하여 기본적인 생화학적 성질에 대한 연구를 수행하였다. 효모를 0.5% glucose, 51 mM $K_2HPO_4$, 22 mM $KH_2PO_4$, 8mM$(NH_4)2SO_4,\;0.4\;m M\;MgSO_4$를 포함하는 최소 배지에서 37$^{\circ}C$로 18시간 동안 배양하였다. 배양된 세포들을 원심분리법으로 수학해 0.1 mM TPP, 0.5 mM DTT, 1${\mu}M$ FAD와 1mM MgCl_2$를 포함하는 20 mM phosphate 완충용액(pH 7.0)에 현탁시켜 하룻밤 동안 방치하였다. 효모를 파쇄한 후 이것의 $10,000{\times}g$ 상충액을 모아 ammonium sulfate 분별 침전법과 DEAE-Se-phacel 그리고 leucine-agarose chromatography법을 이용하여 부분 정제하였다. 단백질의 농도, 시간, 온도, pH, 기질농도 등의 영향을 조사하였으며 측정한 결과 최적온도는 50$^{\circ}C$이고, pH 8.0∼8.5 사이에서 최고 값을 나타냈다. $K_m$과 $V_{max}$값은 각각 8.4 mM과 17.9 nmol/mg/min으로 얻어졌다. 효소의 안정성은 ethylene glycol과 glycerol의 존재하에서 크게 향상됨이 관찰되었다. Feedback inhibition 연구 결과 Val에 의해 가장 많은 영향을 받았고 Leu에는 거의 영향을 받지 않았다.

• 농약과학회지
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• 제2권3호
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• pp.1-20
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• 1998

Chlorsulfuron, one of sulfonylurea herbicides acts through inhibition of acetolactate syuthase (EC 4.1.3.18; ALS, also known as acetohydroxyacid synthase) in the branched-chain amino acid biosynthesis process. After chlorsulfuron-ALS interaction, many physiological and metabolic disruptions occur in plants. However, it is not clear how this chlorsulfuron-ALS interaction affects those physiological and metabolic processes and how this interaction leads subsequently to plant death. Several researchers suggested that the death of chlorsulfuron-treated plants might be due to a shortage of the branched-chain amino acids, an accumulation of toxic metabolites, and/or a depletion of photoassimilates. It remains as a mystery presently, however, if such changes result in the plant death. In this review, we discussed how the chlorsulfuran-ALS interaction leads to physiological and metabolic disruptions in plants.

• BMB Reports
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• 제34권3호
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• pp.244-249
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• 2001

The anabolic acetolactate synthase III was purified to homogeneity from Serratia marcescens using DEAE-Sepharose, Phenyl-Sepharose, and hydroxylapatite column chromatography The native molecular weight of the enzyme was approximately 165 kDa. The enzyme is composed of two large and two small subunits with molecular weights of 64 and 15 kDa, respectively. The N-terminal sequence of the large and small subunit of the enzyme was Ser-Ala-Thr-Pro-Gln-Pro-Ser-Thr-Arg-Phe-Thr-Cys-Ala-Gln-Leu-Ile-Ala-His-Leu and Met-Leu-Gln-Pro-Gln-Asp-Lys-Pro-Gln-Val-Ile-Leu-Glu-Leu-Ala-Val-Arg-Asn-His-Pro-Gly-Val-Met-Ser-His-Val, respectively. The optimum pH and pI value were 7.5 and 5.5, respectively The $IC_{50}$ values were $20\;{\mu}M$ and $14\;{\mu}M$ for valine and herbicide SU7, respectively. The substrate specificity ratio, R value, was determined to be approximately 40, which suggests that this enzyme prefers the formation of $\alpha$-aceto-$\alpha$-hydroxybutyrate leading to the synthesis of isoleucine.

• 한국식품영양학회:학술대회논문집
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• 한국식품영양학회 2001년도 동계 학술심포지움
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• pp.121-121
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• 2001

최소 배지에 여러 아미노산과 대사 산물을 첨가하여 배양시킨 Serratia marcescens ATCC 25419 세포추출물에서여 biodegradative threonine dehydratase (BDTD), biosynthetic threonine dehydratase (BSTD)와 acetolactate syntase (ALS)의 비활성도를 조사하였다. S. marcescens BDTD와 ALS는 낮은 농도 (0.5-2 mM)의 cAMP에 의해 촉진적 조절을 받으며, 비교적 낮은 농도의 isoleucine (1-4 mM)에 의해서는 S. marcescens BSTD의 생합성이 증가되고 높은 농도의 isoleucine (10-30 mM)에서는 감소되고 비교적 낮은 농도의 valine (2-4 mM)에 의해서 S. marcescens ALS의 생합성이 증가되는 것으로 보아 S. marcescens ATCC 25419에서 branched chain 아미노산 생합성 과정의 조절 양상은 Escherichia coli K-12와는 달리, isoleucine의 생합성 과정은 BSTD에 의해 조절되고, valine의 생합성 과정은 ALS에 의해 조절되는 것으로 사료된다.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2003년도 제2차 연례학술대회 발표논문집
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• pp.277-287
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• 2003

Acetolactate synthase (ALS, EC 4.1.3.18; also referred to as acetohydroxy acid synthase) catalyzes the first common step in the biosynthesis of valine, leucine, and isoleucine in microorganisms and plants. Recently X-ray structure of yeast ALS was available. Pair-wise alignment of yeast and tobacco ALS sequences revealed 63% sequence similarity. Using Deep View and automatic modeling on Swiss model server, we have generated reliable models of tobacco ALS based on yeast ALS template with a calculated pair-wise RMSD of 0.86 Angstrom. Functional roles of four residues located on the subunit interface (H142, El43, M350, and R376) were examined by site-directed mutagenesis. Seven mutants were generated and purified, of which three mutants (H142T, M350V, and R376F) were found to be inactivated under various assay conditions. The H142k mutant showed moderately altered kinetic properties. The E143A mutant increased 10-fold in K$_m$ value while other parameters remained unchanged. The M350C mutant was strongly resistant to three tested herbicides, while the R376k mutant can bind with herbicide carder at similar affinity to that of wild type enzyme, as determined by tryptophan quenching study. Except M350V mutant, all other mutants were ate to bind with cofactor FAD. Taken together, it is likely that residues H142 and E143 are located at the active site, while residues M350 and R376 are possibly located at the overlapping region of active site and herbicide binding site of the enzyme. Our data also allows us to hypothesize that the interaction between side chains of residues M350 and R376 are probably essential for the correct conformation of the active site. It remains to be elucidated that, whether the herbicide, upon binding with enzyme, inactivates the enzyme by causing change in the active site allosterically, which is unfavorable for catalytic activity.

• 농약과학회지
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• 제11권4호
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• pp.269-275
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• 2007

4개의 서로 지역 계통별 sulfonylurea(SU)계 제초제 저항성 물달개비의 저항성 정도 차이를 구명하기 위하여 SU계 제초제들에 대한 식물체 및 acetolactate synthase(ALS) 반응 차이를 감수성 계통과 비교 분석하였다. 나주, 논산, 김제 지역에서 채집된 저항성 물달개비들은 SU계 제초제들의 기준량에서 거의 영향을 받지 않았다. 사용된 SU계 제초제들의 기준량에 대한 나주, 논산, 김제 지역계통의 건물 중 50% 억제 제초제 농도인 $GR_{50}$은 감수성계통(청도) 보다 각각 $8{\sim}33$배, $8{\sim}30$배, $7{\sim}32$배 높게 나타났다. 그러나 김해 채집계통의 $GR_{50}$은 감수성 채집계통에 비해 $4{\sim}13$배 높게 나타나 중간정도의 저항성을 보였다. 나주, 논산, 김제에 대한 ALS 50% 억제 제초제 농도인 $I_{50}$은 감수성 채집계통에 비해 각각 $25{\sim}66$배, $9{\sim}26$배, $10{\sim}24$배 높게 나타났다. 그러나 김해 채집계통의 91%은 감수성 채집계통에 비해 $4{\sim}9$배 높게 나타났다.

• 한국잡초학회지
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• 제18권4호
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• pp.333-340
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• 1998

Primisulfuron 또는 Imazethapyr와 Cytochrome P-450 저해제인 PBO의 혼합처리가 옥수수의 생장 및 ALS효소 활성에 미치는 영향을 조사한 결과는 다음과 같다. 1. Pioneer 3751 IR은 Primisulfuron과 Imazethapyr에 Imazethapyr에 높은 내성을 보인 반면, Pioneer 3751과 찰옥 2호는 감수성을 보였다. 2. Pioneer 3751 IR은 Primisulfuron과 PBO혼합처리에서 높은 저항성을 나타내어 PBO혼합처리에 따른 영향은 적었으나 Pioneer 3751,수원 118호와 찰옥 2호는 PBO혼합처리에 따라 생장 저해가 PBO무처리에 비해 높게 나타났다. 3. Pioneer 3751 IR의 생장은 Imazethapyr와 PBO 혼합처리에 따른 영향은 적었으며 Pioneer 3751과 수원 118호, 찰옥 2호는 생장저해가 심하였으나 PBO혼합처리 에 따른 약해 상승작용은 크지 않았다. 4. ALS효소 활성은 Prirnisulfuron은 $0.01{\mu}M$에서부터, 그리고 Imazethapyr는 $1{\mu}M$에서부터 Pioneer 3751 IR 품종을 제외한 3품종에서 현저하게 억제되었으며, Primisulfuron과 PBO혼합처리에 의하여 Pioneer 3751 IR과 Pioneer 3751에서는 활성저해가 더 크게 나타났고 수원 118호와 찰옥 2호에서는 차이가 없었으며, Imazethapyr와 PBO의 혼합처리에서는 4품종에서 모두 약간 억제되었다.

• Weed & Turfgrass Science
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• 제3권2호
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• pp.110-113
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• 2014

The continuous use of acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors has led to the selection of herbicide resistant barnyardgrass populations in direct-seeded rice fields of Korea. This study was conducted to identify herbicide resistant barnyardgrass biotypes and to determine the cross- and multiple-resistance of them. 25% of the population collected from Taeahn was partially resistant to ACCase inhibitors and 22% collected from Kimjae were partially resistant to ALS inhibitors. However, 8.2% of the population from both sites was resistant to ALS and ACCase inhibitors. Resistance to sulfonylurea herbicide, flazasulfuron was identified from two barnyardgrass accessions collected from both Taeahn and Kimjae. One barnyardgrass accession from both sites was resistant to ACCase inhibitor, sethoxydim. The cross-resistance to ALS inhibitors was identified at one barnyardgrass accession from Taeahn and at two accessions from Kimjae. Further, crossresistance to ACCase inhibitors was also identified at barnyardgrass accessions from Taeahn and Kimjae. Multiple-resistance to flazasulfuron and sethoxydim was determined at four barnyardgrass accessions from Taeahn and at six accessions from Kimjae. Therefore, the herbicide mixture and sequences within a growing season or the herbicide rotation with different modes of actions across growing seasons are recommended to control herbicide-resistant barnyardgrass in infested fields.

• 한국잡초학회지
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• 제18권2호
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• pp.171-178
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• 1998

형질전환(形質轉換)된 ALS저해형(沮害型) 제초제(除草劑) 저항성품종(抵抗性品種) Pioneer 3751 IR과 감수성품종(感受性品種) Pioneer 3751, 국내(國內)에서 재배(栽培)되는 옥수수품종(品種) 수원 118호와 찰옥 2호를 대상으로 Primisulfuron과 Terbufos 혼합처리(混合處理)에 따른 옥수수의 �e해반응(藥害反應)과 ALS산소활성(酸素活性)의 차이를 검정하였다. Pioneer 3751 IR의 $GR_{50}$값은 살충제(殺蟲劑) 처리여부(處理與否)와 관계없이 160g ai/ha이상으로 높아 Pioneer 3751에 비하여 Primisulfuron에 저항성(抵抗性)을 나타냈으며 Pioneer 3751은 제초제(除草劑)를 처리(處理)하였을 때 $GR_{50}$값은 136.0g ai/ha었고 살충제(殺蟲劑)와 혼합처리(混合處理)하였을 때는 17.0g ai/ha으로 감소(減少)하였다. 수원 118호는 Primisulfuron 처리(處理)에서 $GR_{50}$값은 92.0g ai/ha이었고 살충제(殺蟲劑)와 혼합처리(混合處理)하였을 때에는 18.5g ai/ha로 감소(減少)되었다. 찰옥 2호는 Primisulfuron에 가장 민감하여 $GR_{50}$값은 29.0g ai/ha이었고 살충제(殺蟲劑)와의 혼합처리(混合處理)에서 14.5g ai/ha로 저하되어 국내품종(國內品種)은 살충제(殺蟲劑)와 제초제(除草劑)의 상호작용(相互作用)으로 약해(藥害)를 많이 받은 것으로 생각된다. Pioneer 3751 IR 품종(品種)의 ALS산소활성(酸素活性)의 $I_{50}$값은 살충제(殺蟲劑)의 처리여부(處理與否)와 관계없이 10.0${\mu}M$이상으로 가장 높았으며, Pioneer 3751은 Primisulfuron 처리(處理)에서 $I_{50}$값은 0.06${\mu}M$이 고 살충제(殺蟲劑)와 혼합처리(混合處理)하였을 때 0.04${\mu}M$로 減少되였다. 수원 118호와 찰옥 2호는 제초제(除草劑) 처리(處理)에서 $I_{50}$ 농도는 각각 7.75, 0.04${\mu}M$이었고 살충제(殺蟲劑)외의 혼합처리(混合處理)에서는 모두 0.01${\mu}M$로 낮아졌다. 따라서 옥수수에서 Primisulfuron에 대한 저항성(抵抗性)은 ALS산소활성(酸素活性)과 밀접한 관계가 있으며 Pioneer 3751 IR을 제외한 품종(品種)에서는 Terbufos 처리(處理)에 따라 약해(藥害)가 크게 유발되었고 ALS산소활성(酸素活性)이 저하되어 Primisulfuron에 대하여 감수성(感受性)을 나타냈다고 생각된다.

• Bulletin of the Korean Chemical Society
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• 제24권12호
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• pp.1799-1804
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• 2003

Acetolatate synthase(ALS) catalyzes the first common step in the biosynthesis of valine, leucine, isoleucine in plants and microorganisms. ALS is the target of several classes of herbicides, including the sulfonylureas, the imidazolinones, and the triazolopyrimidines. To elucidate the roles of arginine residues in tobacco ALS, chemical modification and site-directed mutagenesis were performed. Recombinant tobacco ALS was expressed in E. coli and purified to homogeneity. The ALS was inactivated by arginine specific reagents, phenylglyoxal and 2,3-butanedione. The rate of inactivation was a function of the concentration of modifier. The inactivation by butanedione was enhanced by borate, and the inactivation was reversible on removal of excess butanedione and borate. The substrate pyruvate and competitive inhibitors fluoropyruvate and phenylpyruvate protected the enzyme against inactivation by both modifiers. The mutation of well-conserved Arg198 of the ALS by Gln abolished the enzymatic activity as well as the binding affinity for cofactor FAD. However, the mutation of R198K did not affect significantly the binding of FAD to the enzyme. Taken together, the results imply that Arg198 is essential for the catalytic activity of the ALS and involved in the binding of FAD, and that the positive charge of the Arg is crucial for the interaction with negatively charged FAD.