• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.512.1-512
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• 1986

The cdd gene of Bacillus subtilis, encoding the deoxycytidinecytidine deaminase of pyrimidine nucleotide biosynthesis has been cloned into the EcoRl site of pBR322. The recombinant plasmid, pSol, promoted the synthesis of 100-140 fold elevated levels of the enzyme. A comparison of the polypeptides encoded by cdd complementing and non-complementing plasmids in the mini cell showed the gene product to have a molecular mass of approximately 14 kDa. The nucleotide sequence of the gene and 460 base pairs upstream from the coding region was determined. An open-reading frame, encoding a protein with a calculated molecular mass of 14337 Da, was deduced to be the coding region for cdd. However, the enzyme has an apparent molecular mass of 54 kDa as determined by gel filteration, whereas sucrose density gradient centrifugation shows 58 kDa. It means that the enzyme could be forming a tetramer in a physiological state. About 28 amino acids of the N-tetramer in a physiological state. About 28 amino acids of the N-terminal presumably form a signal for membrane translocation and six cystein residues are contained in the structure. S1 nuclease mapping indicated that transcription of cdd is initiated 17 base pairs upstream from the translational start. The structural characterization of the odd gene was performed.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.29-36
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• 2007

The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones were screened on the LB agar plates supplemented with xylan, by the Congo-red staining method. The xynA gene consists of a 630-bp open reading frame encoding a protein of 210 amino acids, and the XynA preprotein contains a 28-residues signal peptide whose cleavage yields a l82-residues mature protein of a calculated molecular weight of 20,000Da and pI value of 8.77. The cloned DNA fragment also has another ORF of 873 nucleotides that showed 76% identity to the putative transcriptional activator of Bacillus halodurans C-125. Most of the xylanase activity was found in the periplasmic space of E. coli. The xynA gene was subcloned into pQE60 expression vector to fuse with six histidine-tag. The recombinant xylanase A was purified by heating and immobilized metal affinity chromatography. The optimum pH and temperature of the purified enzyme were 6.0 and $60^{\circ}C$, respectively. This histidine-tagged xylanase A was less thermostable than the native enzyme.

• Journal of Microbiology and Biotechnology
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• v.5 no.1
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• pp.26-30
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• 1995

The cytoplasmic endo-$\beta$-l, 4-glucanase (endoglucanase) was purified from cell extracts of Escherichia coli (pBS1) transformant carrying the Bacillus subtilis endo-$\beta$-l, 4-glucanase gene after full growth, and its molecular weight was found to be 52 kilodaltons (kDa). The endo-$\beta$-l, 4-glucanase isolated from the periplasmic space was smaller than 52-kDa cytoplasmic enzyme. The 52-kDa endoglucanase was found to be cleaved in the periplasm and finally converted to 34.5-kDa protein. Small amounts of both 52-kDa and 34.5-kDa proteins were secreted into the culture broth. The cleavage took place in the C-terminal portion of the enzyme. The N-terminal amino acid residues of both 52-kDa and 34.5-kDa enzymes were determined to be the same, Ala, the 30th residue of the primary translation product. Cleavage of the C-terminal portion showed to have no significant effect on the basic enzyme properties.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.68-75
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• 2000

D-Tagatose is a potential bulking agent in food as a non-calorific sweetener. To produce D-tagatose from cheaper resources, plasmids harboring the L-arabinose isomerase gene (araA) from Escherichia coli was constructed because L-arabinose isomerase was previously suggested as an enzyme that mediates the bioconversion of galactose to tagatose as well as that of arabinose to ribulose. In the cultures of recombinant E.coli with pTC101, which harboring araA of E.coli, tagatose was produced from galactose in 9.9 % yield. The enzyme extract of E.coli containing pTC101 also converted galactose into tagatose in 96.4 % yield. For the economic production of D-tagatose, an L-arabinose isomerase of E.coli was immobilized using covalent binding on agarose. While the free L-arabinose isomerase produced tagatose with the rate of 0.48 mg/U$.$day, the immobilized one stably converted galactose into average 7.5 g/l$.$day of tagatose during 7 days with higher productivity of 0.87 mg/U$.$day. In the scaled up immobilized enzyme system, 99.9 g/l of tagatose was produced from galactose with 20 % equilibrium in 48 hrs. The process was stably repeated additional 2 times with tagatose production of 104.1 and 103.5 g/l.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.244-250
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• 2000

An ${\alpha}-glucosidase$ gene (aglA) from thermophilic Bacillus sp. DG0303 was cloned, sequenced, and expressed in Escherichia coli. The aglA was localized to the 2.1-kb PvuI-XmnI region within the 5.9-kb DNA insert of the gybrid plasmid pAG1. The gene consisted of an open reading frame of 1,686 bp with an unusual GTG initiation codon and TGA termination codon. The amino acid sequence deduced from the nucleotide sequence predicted a protein of 562 amino acid residues with a M, of 66,551 dalton. A comparative amino acid sequence analysis revealed that DG0303 ${\alpha}-glucosidase$ is related to bacillary oligo-1, 6-glucosidases. The Bacillus sp. DG0303 ${\alpha}-glucosidase$ showed a high sequence identity (36-59%) to the B. flavocaldarius, B. cereus, and B. thermoglucosidasius oligo-1, 6-glucosidases. The number of prolines in theses four ${\alpha}-glucosidases. was observed to increase with increasing thermostability of these enzymes. The cloned ${\alpha}-glucosidase was purified from E. coli $DH5{\alpha}$ bearing pAG1 and characterized. The recombinant enzyme was identical with the native enzyme in its optimum pH and in its molecular mass, estimated by sodium dodecy1 sulfate-polyacrylamide gel electrophoresis. The temperature optimum of the cloned ${\alpha}-glucosidase$ was lower than that of the native enzyme.

• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.445-448
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• 2002

The Pseudomonas fluorescens KCTC 1767, a selected and identified as potential candidate for stereo-specific resolution of rac-ketoprofen ethyl ester, was systematically investigated in order to induce the high level expression and detailed characterization of the expressing enzyme esterase. We cloned the esterase gene from chromosomal DNA of Pseudomonas fluorescens KCTC 1767 by PCR with two synthetic primers that desinged for simple purification. The recombinant esterase from Pseudomonas fluorescens KCTC 1767 exibited a high conversion rate and enantioselectivity to the (S)-ketoprofen ethyl ester as expected. The enzyme was easily purified to homogeniety by using a metal chelating affinity chromatography as a protein with poly histidine taq, and thus obtained 0.6 mg of protein from a 100 mL culture broth in a single step. The purified enzyme was steadily stable at the pH range from 7.0 to 10. The activity was also retained to be about 70% after the preincubation at $40^{\circ}C$ but over $50^{\circ}C$ lost the activity completely. The molecular mass of the esterase was estimated to be about 43 kDa on SDS-PAGE, and an identical result was also shown in gel filteration chromatography. The specific activity was calculated 27 mM/mg-protein/min by using the rac-ketoprofen ethly ester as a substrate.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.66-73
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• 2015

The pabS gene of Agaricus bisporus 02 encoding a putative PABA synthase was cloned, and then the recombinant protein was expressed in Escherichia coli BL21 under the control of the T7 promoter. The enzyme with an N-terminal GST tag or His tag, designated GST-AbADCS or His-AbADCS, was purified with glutathione Sepharose 4B or Ni Sepharose 6 Fast Flow. The enzyme was an aminodeoxychorismate synthase, and it was necessary to add with an aminodeoxychorismate lyase for synthesizing PABA. AbADCS has maximum activity at a temperature of approximately 25℃ and pH 8.0. Magnesium or manganese ions were necessary for the enzymatic activity. The Michaelis-Menten constant for chorismate was 0.12 mM, and 2.55 mM for glutamine. H₂O₂ did distinct damage on the activity of the enzyme, which could be slightly recovered by Hsp20. Sulfydryl reagents could remarkably promote its activity, suggesting that cysteine residues are essential for catalytic function.

• Korean Journal of Animal Reproduction
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• v.22 no.1
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• pp.81-87
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• 1998

This experiment was carried out with 12 Korean native heifers(8~12month old, body weight, 160~240kg) raised at a farm of Chang-Soo Livestock Cooperatives to evaluate the effects of rGH(recombinant growth hormone) on serum concentrations of growth hormone, estrogen, and IGF-I, weight gain, teat volume gain and processing enzyme activity of IGF-I, binding protein III at 28 day intervals. Animals used were injected with 250mg rGH at 14 day intervals from December to Ferbruary in 1994. The significant difference was found in the group of treatment on the 4th week in the endogenous GH(p<.01) and 8th week in estrogen and IGF-I(p<.05) after injectin of rGH in Korean native heifers. There were significant differences between control group and treatment group in weight and teat volume on 8th week after treatment(p<.05). Processing enzyme activity before injection of rGH were low. However, heifers injected with 250mg of rGH showed that processing enzyme activity of IGF binding protein was highly increased throughout the experiment. Present results suggest that injection of exogenous rGH to heifers can increase the growth performance and udder development of Korean native heifers by the endogenous hormonal changes.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.286-290
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• 2006

A genomic library of Streptococcus vestibularis ATCC49124 was constructed in an E. coli plasmid vector, and the urease-positive transformants harboring the urease gene cluster were isolated on Christensen-urea agar plates. The minimal DNA region required for urease activity was located in a 5.6 kb DNA fragment, and a DNA sequence analysis revealed the presence of a partial ureI gene and seven complete open reading frames, corresponding to ureA, B, C, E, F, G, and D, respectively. The nucleotide sequence over the entire ure gene cluster and 3'-end flanking region of S. vestibularis was up to 95% identical to that of S. salivarius, another closely related oral bacterium, and S. thermophilus, isolated from dairy products. The predicted amino acid sequences for the structural peptides were 98-100% identical to the corresponding peptides in S. salivarius and S. thermophilus, respectively, whereas those for the accessory proteins were 96-100% identical. The recombinant E. coli strain containing the S. vestibularis ure gene cluster expressed a high level of the functional urease holoenzyme when grown in a medium supplemented with 1 mM nickel chloride. The enzyme was purified over 49-fold by using DEAE-Sepharose FF, Superdex HR 200, and Mono-Q HR 5/5 column chromatography. The specific activity of the purified enzyme was 2,019 U/mg, and the Michaelis constant ($K_{m}$) of the enzyme was estimated to be 1.4 mM urea. A Superose 6HR gel filtration chromatography study demonstrated that the native molecular weight was about 196 kDa.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.773-779
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• 2002

A gene (hap) encoding aminopeptidase from the chromosomal DNA of Bacillus licheniformis was cloned. The gene is 1,347 bp long and encodes a 449 amino acid preproprotein with a major mature region of 401 amino acids (calculated molecular mass 43,241 Da). N-Terminal sequence of the purified protein revealed a potential presence of N-terminal propeptide. The deduced primary amino acid sequence and the mass analysis of the purified protein suggested that a C-terminal peptide YSSVAQ was also cleaved off by a possible endogeneous protease. Tho amino acid sequence displayed 58% identity with that of the aminopeptidase from alkaliphilic Bacillus halodurans. This bacterial enzyme was overexpressed in recombinant Escherichia coli and Bacillus subtilis cells. Clones containing the intact hap gene, including its own promoter and signal sequence, gave rise to the synthesis of extracellular and thrmostable enzyme by B. subtilis transformants. The secreted protein exhibited the same biochemical properties and the similar apparent molecular mass as the B. lichenzyormis original enzyme.