• 제목/요약/키워드: biochemical characterization

검색결과 684건 처리시간 0.034초

Characterization of the recombinant cellulase A from Thermotoga maritima

  • Kim, Chung Ho
    • Journal of Applied Biological Chemistry
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    • 제64권3호
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    • pp.213-216
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    • 2021
  • A gene encoding thermostable cellulase A (TmCelA) was isolated from Thermotoga maritima. The open reading frame of TmCelA gene was 774 bp long which predicted to encode 257 amino acid residues with a molecular weight of 29,732 Da. To examine the biochemical properties, the TmCelA was overexpressed in E. coli BL21, and expressed protein was purified. The optimum temperature of recombinant TmCelA was 90-95 ℃, and the optimum pH of recombinant TmCelA was approximately pH 5.0. Recombinant TmCelA was stable at temperature below 90 ℃.

Production of Maltopentaose and Biochemical Characterization of Maltopentaose-Forming Amylase

  • Kim, Young-Min;Ryu, Hwa-Ja;Lee, Sun-Ok;Seo, Eun-Seong;Lee, So-Young;Yoo, Sun-Kyun;Cho, Dong-Lyun;Kim, Do-Man;Kimura, Atsuo;Chiba, Seiya;Lee, Jin-Ha
    • Journal of Microbiology and Biotechnology
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    • 제11권4호
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    • pp.636-643
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    • 2001
  • Bacillus sp. AIR-5, a strain from soil, produced an extracellular maltopentaose-forming amylase from amylose and soluble starch. This bacterium produced 8.9 g/l of maltopentaose from 40 g/l of soluble starch in a batch fermentation and the maltopentaose made up 90 % of the maltooligosaccharides produced (from maltose to maltoheptaose). The culture supernatant was concentrated using a 30 K molecular weight cut-off membrane and purified by DEAE-Cellulose and Sephadex G-150 column chromatographies. The purified protein showed one band on a native-PAGE and its molecular mass was estimated as 250 kDa. The 250-kDa protein was composed of tetramers of a 63-kDa protein. the isoelectric point of the purified protein was pH 6.9, and the optimum temperature for the enzyme activity was $45^{\circ}C$. The enzyme was quickly inactivated above $55^{\circ}C$, and showed a maximum activity at pH 8.5 and over 90% stability between a pH of 6 to 10. The putative N-terminal amino acid sequence of AIR-5 amylase, ATINNGTLMQYFEWYVPNDG, showed a 96% sequence similarity with that of BLA, a general liquefying amylase.

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Structural and Biochemical Characterization of the Two Drosophila Low Molecular Weight-Protein Tyrosine Phosphatases DARP and Primo-1

  • Lee, Hye Seon;Mo, Yeajin;Shin, Ho-Chul;Kim, Seung Jun;Ku, Bonsu
    • Molecules and Cells
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    • 제43권12호
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    • pp.1035-1045
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    • 2020
  • The Drosophila genome contains four low molecular weight-protein tyrosine phosphatase (LMW-PTP) members: Primo-1, Primo-2, CG14297, and CG31469. The lack of intensive biochemical analysis has limited our understanding of these proteins. Primo-1 and CG31469 were previously classified as pseudophosphatases, but CG31469 was also suggested to be a putative protein arginine phosphatase. Herein, we present the crystal structures of CG31469 and Primo-1, which are the first Drosophila LMW-PTP structures. Structural analysis showed that the two proteins adopt the typical LMW-PTP fold and have a canonically arranged P-loop. Intriguingly, while Primo-1 is presumed to be a canonical LMW-PTP, CG31469 is unique as it contains a threonine residue at the fifth position of the P-loop motif instead of highly conserved isoleucine and a characteristically narrow active site pocket, which should facilitate the accommodation of phosphoarginine. Subsequent biochemical analysis revealed that Primo-1 and CG31469 are enzymatically active on phosphotyrosine and phosphoarginine, respectively, refuting their classification as pseudophosphatases. Collectively, we provide structural and biochemical data on two Drosophila proteins: Primo-1, the canonical LMW-PTP protein, and CG31469, the first investigated eukaryotic protein arginine phosphatase. We named CG31469 as DARP, which stands for Drosophila ARginine Phosphatase.

코코넛 오일로부터 유래된 카르복실레이트계 음이온 계면활성제의 합성 및 계면 특성에 관한 연구 (Synthesis of Carboxylate-Based Anionic surfactant from Coconut Oil Source and Characterization of Interfacial Properties)

  • 이예진;박기호;신희동;임종주
    • 공업화학
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    • 제32권3호
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    • pp.260-267
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    • 2021
  • 본 연구에서는 코코넛 오일로부터 카르복실레이트계 음이온 계면활성제 SLEC-3을 합성하였으며, 합성된 계면활성제의 구조를 FT-IR, 1H-NMR 및 13C-NMR 분석을 통하여 확인하였다. 합성한 계면활성제 SLEC-3에 대하여 임계 마이셀 농도, 정적 및 동적 표면장력, 유화력, 거품 안정성 등의 계면 물성을 측정한 결과, 기존 세제 제품에서 널리 사용되는 음이온 계면활성제 SLES와 비교하여 계면 활성이 보다 우수하고 계면 에너지를 낮추는데 더 효과적이었다. 또한 SLCE-3에 대한 생분해성, 급성 경구 독성 및 급성 피부자극 시험을 실시한 결과, 저자극 및 저독성을 가지고 있기 때문에 세제 및 세정제 제품에 적용할 수 있을 것으로 판단되었다.

Crystal Structure and Biochemical Analysis of a Cytochrome P450 Steroid Hydroxylase (BaCYP106A6) from Bacillus Species

  • Ki-Hwa Kim;Hackwon Do;Chang Woo Lee;Pradeep Subedi;Mieyoung Choi;Yewon Nam;Jun Hyuck Lee;Tae-Jin Oh
    • Journal of Microbiology and Biotechnology
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    • 제33권3호
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    • pp.387-397
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    • 2023
  • Cytochrome P450 (CYP) is a heme-containing enzyme that catalyzes hydroxylation reactions with various substrate molecules. Steroid hydroxylases are particularly useful for effectively introducing hydroxyl groups into a wide range of steroids in the pharmaceutical industry. This study reports a newly identified CYP steroid hydroxylase (BaCYP106A6) from the bacterium Bacillus sp. and characterizes it using an in vitro enzyme assay and structural investigation. Bioconversion assays indicated that BaCYP106A1 catalyzes the hydroxylation of progesterone and androstenedione, whereas no or low conversion was observed with 11β-hydroxysteroids such as cortisol, corticosterone, dexamethasone, and prednisolone. In addition, the crystal structure of BaCYP106A6 was determined at a resolution of 2.8 Å to investigate the configuration of the substrate-binding site and understand substrate preference. This structural characterization and comparison with other bacterial steroid hydroxylase CYPs allowed us to identify a unique Arg295 residue that may serve as the key residue for substrate specificity and regioselectivity in BaCYP106A6. This observation provides valuable background for further protein engineering to design commercially useful CYP steroid hydroxylases with different substrate specificities.

The genetic structure of taro: a comparison of RAPD and isozyme markers

  • Sharma, Kamal;Mishra, Ajay Kumar;Misra, Raj Shekhar
    • Plant Biotechnology Reports
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    • 제2권3호
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    • pp.191-198
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    • 2008
  • Germplasm characterization and evolutionary process in viable populations are important links between the conservation and utilization of plant genetic resources. Here, an investigation is made, based on molecular and biochemical techniques for assessing and exploiting the genetic variability in germplasm characterization of taro, which would be useful in plant breeding and ex situ conservation of taro plant genetic resources. Geographical differentiation and phylogenetic relationships of Indian taro, Colocasia esculenta (L.) Schott, were analyzed by random amplified polymorphic DNA (RAPD) and isozyme of seven enzyme systems with specific reference to the Muktakeshi accession, which has been to be proved resistant to taro leaf blight caused by P. colocasiae. The significant differentiations in Indian taro cultivars were clearly demonstrated by RAPD and isozyme analysis. RAPD markers showed higher values for genetic differentiation among taro cultivars and lower coefficient of variation than those obtained from isozymes. Genetic differentiation was evident in the taro accessions collected from different regions of India. It appears that when taro cultivation was introduced to a new area, only a small fraction of genetic variability in heterogeneous taro populations was transferred, possibly causing random differentiation among locally adapted taro populations. The selected primers will be useful for future genetic analysis and provide taro breeders with a genetic basis for selection of parents for crop improvement. Polymorphic markers identified in the DNA fingerprinting study will be useful for screening a segregating population, which is being generated in our laboratory aimed at developing a taro genetic linkage map.

카스텔란니가시아메바(Acanthamoeba castellanii) 한국 토양분리주 KA/S2의 생화학적 및 분자생물학적 특성 (Biochemical and molecular characterization of a strain KA/S2 of Acnnthamoebc castellanii isolated from Korean soil)

  • 정동일;공현희
    • Parasites, Hosts and Diseases
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    • 제34권1호
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    • pp.79-86
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    • 1996
  • 형태적으로 Aconaqmoebcusteuon리로 동정된 한국토양분리주 KA/S2의 일부 특성을 파악하여 A. castellanii로 알려진 4가지 reference 주(Castellani, Neff, fna 및 Chang주) 와 비교하였다 K4/s2주의 mitochondria(Mt) DNARFLP와 isoelectricforusing(IEF)로 분석한 동위효소 양상은 California 토양에서 분리된 Neff주의 그것과 동일하였으나 고 외의 주들 사이에는 심한 다양성이 과찰되었다. Chang주의 형태 및 전 단백질 양상은 다른 주에 비해 독특하였다. Aconamoeba app. 분리주의 동정 및 특성 파악에 Mt DNA RFLP 분석이 매우 유용할을 확인하였다. Aconamoebacasteunil의 우리말 학명을 카스텔라니가시아메바로 제안한다.

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Cloning and Characterization of a Novel ${\alpha}$-Amylase from a Fecal Microbial Metagenome

  • Xu, Bo;Yang, Fuya;Xiong, Caiyun;Li, Junjun;Tang, Xianghua;Zhou, Junpei;Xie, Zhenrong;Ding, Junmei;Yang, Yunjuan;Huang, Zunxi
    • Journal of Microbiology and Biotechnology
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    • 제24권4호
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    • pp.447-452
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    • 2014
  • To isolate novel and useful microbial enzymes from uncultured gastrointestinal microorganisms, a fecal microbial metagenomic library of the pygmy loris was constructed. The library was screened for amylolytic activity, and 8 of 50,000 recombinant clones showed amylolytic activity. Subcloning and sequence analysis of a positive clone led to the identification a novel gene (amyPL) coding for ${\alpha}$-amylase. AmyPL was expressed in Escherichia coli BL21 (DE3) and the purified AmyPL was enzymatically characterized. This study is the first to report the molecular and biochemical characterization of a novel ${\alpha}$-amylase from a gastrointestinal metagenomic library.