• Journal of Microbiology and Biotechnology
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• 제13권5호
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• pp.738-744
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• 2003

The gene ADH encoding NAD-dependent alcohol dehydrogenase from Bacillus stearothennophilus was cloned and overexpressed as a GST fusion protein at a high level in Escherichia coli. The expressed fusion protein was purified simply by glutathione affinity chromatography. GST fusion protein was then cleaved by thrombin, while soluble enzyme was further purified by glutathione affinity chromatography. The recombinant enzyme had the same elctrophoretic mobility as the native enzyme from Bacillus stearothennophilus. The recombinant enzyme catalyzed the oxidation of a number of alcohols and exhibited high activities towards secondary alcohols. The $K_m\;and\;V_{max}$ values of the recombinant enzyme for ethanol were 5.11 mM and 61.35 U/mg, respectively. Pyridine and imidazole notably inhibited the enzymatic activity. The activity of the recombinant enzyme optimally proceeded at pH 9.0 and $70^{\circ}C$. The midpoint of the temperature-stability curve for the recombinant enzyme was approximately $68^{\circ}C$, and the enzyme was not completely inactivated even at $85^{\circ}C$. The recombinant enzyme showed a high resistance towards denaturing agents (0.05% SDS, 0.1 M urea). Therefore, due to its stability and relatively broad substrate specificity, the recombinant enzyme could be utilized in bio-industrial processes and biosensors.

• Journal of mucopolysaccharidosis and rare diseases
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• 제4권1호
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• pp.11-13
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• 2018

In Malaysia, diagnosis and treatment of patients with mucopolysaccharidoses (MPS) is mainly localized at Hospital Kuala Lumpur, which is the national referral center for rare diseases. To date there are 83 patients diagnosed with MPS in our center, with MPS II being the commonest. The Malaysian National Medicines Policy second edition has a specific section on the orphan drugs which includes recombinant human enzyme for enzyme replacement therapy (ERT) in MPS. So far, National Pharmaceutical Regulatory Agency Malaysia has approved recombinant human enzyme for MPS types I (Loranidase), II (idursulfase), IVA (elosulfase alfa), and VI (Galsufase). Access to Idursulfase beta (another recombinant human enzyme for MPS II) and vestronidase alfa-vjbk (MPS VII) required special authorization on named patient basic. Currently there are 25 patients receiving ERT, 70% of the funding are from Ministry of Health (MOH), the remaining 30% are from various charitable funds and humanitarian programs. Thirteen newly diagnosed patients have to queue for an additional fund. Four patients have been treated with Hematopoietic stem cell transplant. MOH has also published guidelines regarding the patient selection criteria for ERT and treatment monitoring schedule.

• Journal of Microbiology and Biotechnology
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• 제2권3호
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• pp.161-165
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• 1992

The gene encoding the bacteriolytic enzyme cell wall peptidoglycan hydrolase from alkalophilic Bacillus sp. was cloned in E. coli using pBR322 as a vector. A recombinant plasmid, designated pYTR451, was isolated and the size of the cloned HindIII fragment was found to be 4.8 Kb. The cell wall hydrolysis activity of an extract of the E. coli harboring the recombinant plasmid pYTR 451 was detected by SDS- polyacrylamide gel containing 0.2% (w/v) purified cell wall of Bacillus sp. The molecular weight of the enzyme was estimated to be about 27, 000 corresponding to the molecular weight of the Bacillus sp. bacteriolytic enzyme. The recombinant plasmid was found to contain the fragment originated from Bacillus sp. YJ-451 chromosomal DNA by Southern hybridization.

• BMB Reports
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• 제40권3호
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• pp.333-340
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• 2007

Gene encoding cyclodextrin glycosyltransferase (CGTase), from thermotolerant Paenibacillus sp. T16 isolated from hot spring area in northern Thailand, was cloned and expressed in E. coli (JM109). The nucleotide sequences of both wild type and transformed CGTases consisted of 2139 bp open reading frame, 713 deduced amino acids residues with difference of 4 amino acid residues. The recombinant cells required 24 h culture time and a neutral pH for culture medium to produce compatible amount of CGTase compared to 72 h culture time and pH 10 for wild type. The recombinant and wild-type CGTases were purified by starch adsorption and phenyl sepharose column chromatography and characterized in parallel. Both enzymes showed molecular weight of 77 kDa and similar optimum pHs and temperatures with recombinant enzyme showing broader range. There were some significant difference in pH, temperature stability and kinetic parameters. The presence of high starch concentration resulted in higher thermostability in recombinant enzyme than the wild type. The recombinant enzyme was more stable at higher temperature and lower pH, with lower $K_m$ for coupling reaction using cellobiose and cyclodextrins as substrates.

• Fisheries and Aquatic Sciences
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• 제8권3호
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• pp.118-121
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• 2005

Arylsulfatase cloned from a marine bacterium, Pseudoalteromonas carrageenovora, was over-expressed in Escherichia coli. Most of the recombinant arylsulfatase was found in the cell lysate with induction up to $10{\mu}M$ IPTG. However, enzyme activity was observed both in the culture supernatant and cell lysate by induction with IPTG concentration of $50-5,000{\mu}M$. Most of the recombinant enzyme was localized in the periplasmic space with $10{\mu}M$ IPTG induction, while half of the enzyme was distributed in the periplasmic space with $50{\mu}M$ IPTG induction. Cell growth and arylsulfatase activity did not change with the induction time, and the level of recombinant arylsulfatase expression was maintained at 4-5 U/mL after 6 to 14 hr of culture.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.167-172
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• 2001

A cDNA fragment encoding the chloroplastic fructose-1, 6-bisphosphatase (FBPase) was cloned via PCR from the cDNA library of pea leaves. The cloned cDNA, about 1.05 kbp without signal sequence, was introduced into a pET-28a vector for expression in E. coli strain BL21(DE3)pLysS. The recombinant FBPase was purified through $Ni^+-NTA$ affinity chromatography and characterized. Molecular mass of the monomer was about 42,000. Enzymatic activity of the purified enzyme as the native pea chloroplastic FBPase was the highest at alkaline pH (pH 9.0). The recombinant enzyme was activated by a reducing agent DTT and was insensitive to AMP. The activation energy (Ea) and Arrehenius frequency factor were 42.67 kcal/mol and $2.65{\times}10^{14}/s$, respectively, slightly higher than those of the native enzyme. $K_M$ and $V_{max}$ were $99.98{\mu}M$ and $52.9{\mu}M/min$, respectively, which were comparable with the native enzyme.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.92-96
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• 2001

Effect of environmental factors on the expression of soluble forms of Bacillus macerans cyclodextrin glycosyltransferase in recombinant Escherichia coli BL21(DE3)pLysE:pTCGT1 were investigated. The amount of soluble CGTase produced in the cell was measured by determining its enzymatic activity. The soluble fractionof the enzyme was increased by lowering the culture temperature to $30{\circ}C$ and medium pH to 5.8 compared to the enzyme production in LB medium at $37^{\circ}C$ and pH7.0. Addition of 0.2 M NaCl enhanced enzyme expression levels at the expense of cell growth. Glycine betaine that was added after 3 h of induction protected not only the cell growth from hig osmotic pressue but also hepld in vivo folding of CGTase in recombinant E. coli. Addition of 1 mM $CaCl_2$ was also effective in the expression of soluble CGTase, resulting in 15 U/ml of the enzyme activity.

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

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.255-259
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• 1999

A 6.9-kb DNA fragment including the minimal Bacillus pasteurii urease gene cluster was subcloned into a high-copy-number plasmid vector, pUC19, and the recombinant B. pasteurii urease was overexpressed in Escherichia coli. The recombinant urease was purified 25.9-fold by using combinations of anion-exchange and gel-filtration chromatography followed by Mono-Q chromatography on a FPLC. N-terminal peptide sequencing analyses revealed that two distinct smaller peptide bands resolved on a 10-18％ gradient SDS-PAGE corresponded to UreA and UreB peptides, respectively. It was also shown that the ureB gene was translated from a GUG codon and the first methionine residue was post-translationally cleaved off. The native molecular weight of the recombinant urease was 176,000 and 2 nickel atoms were present per catalytic unit. pH stability studies of the purified enzyme showed that the recombinant Bacillus pasteurii urease is stable in alkaline pH range, which is similar to the enzyme of the evolutionarily related bacterium, Sporosarcina ureae.

• Journal of Microbiology and Biotechnology
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• 제22권10호
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• pp.1388-1394
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• 2012

A xylanase-producing thermophilic strain, Geobacillus sp. TC-W7, was isolated from a hot spring in Yongtai (Fuzhou, China). Subsequently, the xylanase gene that encoded 407 amino acids was cloned and expressed. The recombinant xylanase was purified by GST affinity chromatography and exhibited maximum activity at $75^{\circ}C$ and a pH of 8.2. The enzyme was active up to $95^{\circ}C$ and showed activity over a wide pH range of 5.2 to 10.2. Additionally, the recombinant xylanase showed high thermostability and pH stability. More than 85% of the enzyme's activity was retained after incubation at $70^{\circ}C$ for 90 min at a pH of 8.2. The activity of the recombinant xylanase was enhanced by treatment with 10 mM enzyme inhibitors (DDT, Tween-20, 2-Me, or TritonX-100) and was inhibited by EDTA or PMSF. Its functionality was stable in the presence of $Li^+$, $Na^+$, and $K^+$, but inhibited by $Hg^{2+}$, $Ni^{2+}$, $Co^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Pb^{2+}$, $Fe^{3+}$, and $Al^{3+}$. The functionality of the crude xylanase had similar properties to the recombinant xylanase except for when it was treated with $Al^{2+}$ or $Fe^{2+}$. The enzyme might be a promising candidate for various industrial applications such as the biofuel, food, and paper and pulp industries.