• KSBB Journal
• /
• v.11 no.6
• /
• pp.704-711
• /
• 1996

An optimal process design of a foreign protein production system was carried out using a bioprocess flowsheeting software, BioPro Designer, with a capability of economic analysis. The flowsheeting program was applied to a production system of the tailspike protein of Salmonella phage P22, and helped save time and efforts in selecting an optimal process. A wild type tailspike and two types of mutant tailspikes, tsf G244\longrightarrow,R and Su A334\longrightarrowV, were considered in this study to show that the folding characteristics of foreign protein produced inside host influenced the selection of the best production system. An optimal production system for mature tailspike was chosen under the criterion of capital investment per unit mass of mature protein recovered.

• The Journal of the Korean Society for Microbiology
• /
• v.20 no.1
• /
• pp.1-11
• /
• 1985

A total of 211 strains of Staphylococcus aureus which included 118 strains isolated from various clinical specimens of admitted patients of University Hospital with systemic or severe cases of infection and 93 strains from infected skin diseases of out-patients of dermatology clinic located in rural area, were tested for the antimicrobial susceptibility to the 12 drugs of common use and the phage typing. An these were subjected to the study of plasmid profile analysis for the molecular epidemiology of nosocomial infections. University Hospital(UH) isolates showed higher frequency of resistance than local clinic(LC) isolates against 10 drugs excluding tetracycline(Tc), and trimethoprim(Tp). The MIC of UH isolates were above than $128{\mu}g/ml$ against 9 drugs except Tc, gentamicin(Gm), and Tp, but LC isolates did not show such a high level of MIC. There was difference of MIC needed to inhibit 90% of strains(MIC90) against each drugs tested between two groups of UH and LC isolates. UH isolates showed 2 to 4 times higher value of MIC90 by two-fold serial dilution of drug concentration than LC isolates. Tp was considered as an effective drug in treatment of staphylococcal infections whereas ampicillin and Gm were appeared to be ineffective. Seventy-three strains(61.9%) of UH isolates and 70(69.9%) of LC were typable with phages from Colindale Reference Laboratory. The prevailing phage type of UH isolates belonged to lytic group II were 27 strains(22.9%) and those of LC isolates belonged to lytic group II were 23 strains(24.7%). Thirteen strains(11.0%) of UH isolates were multiply resistant to more than 5 drugs to 10 drugs but none of LC isolates. Through the lysis method of Kado and Liu followed by agarose gel electrophoresis, none of 211 strains showed plasmid profile. These results were confirmed by re-examination through the method of Birnboim and Doly.

• BMB Reports
• /
• v.28 no.4
• /
• pp.336-341
• /
• 1995

Using a mutant M13 phage derivative lacking a great part of the complementary strand synthesis origin, we identified six single-strand initiation (ssi) signals for DNA replication in pACYC184, pLG214, pGKV21, and pDPT270 plasmids, and named them $ssiA_{YC}$, $ssiA_{LG}$, $ssiB_{LG}$, $ssiA_{KV}$, $ssiA_{PT}$, and $ssiB_{PT}$, respectively. Two of them were from pDPT270, one from downstream the on of pACYC184, two from pLG214, one from upstream the plus origin of pGKV21. Introduction of these ssi signals into the deleted $ori_c$ site of a mutant filamentous M13 phage ($M13{\Delta}lac182$) resulted in the restoration of growth activity of this phage. These ssi signals were classified into a number of groups on the basis of sequence similarity. $ssiA_{YC}$ and $ssiA_{LG}$ show extensive sequence homology to the n'-site (primosome assembly sites) of ColE1, whereas $ssiB_{PT}$ is homologous to the n'-site of ${\Phi}X174$. $ssiA_{PT}$ belongs to G4-type ssi signals which require only dnaG primase and SSB protein for the priming of replication. In addition, possible biological roles of these ssi signals are discussed.

• BMB Reports
• /
• v.40 no.4
• /
• pp.539-546
• /
• 2007

The lysozymes encoded by bacteriophage T7 and K11 are both bifunctional enzymes sharing an extensive sequence homology (75%). The constructions of chimeric lysozymes were carried out by swapping the N-terminal and C-terminal domains between phage T7 and K11 lysozymes. This technique generated two chimeras, T7K11-lysozyme (N-terminal T7 domain and C-terminal K11 domain) and K11T7-lysozyme (N-terminal K11 domain and C-terminal T7 domain), which are both enzymatically active. The amidase activity of T7K11-lysozyme is comparable with the parental enzymes while K11T7-lysozyme exhibits an activity that is approximately 45% greater than the wild-type lysozymes. Moreover, these chimeric constructs have optimum pH of 7.2-7.4 similar to the parental lysozymes but exhibit greater thermal stabilities. On the other hand, the chimeras inhibit transcription comparable with the parental lysozymes depending on the source of their N-terminals. Taken together, our results indicated that domain swapping technique localizes the N-terminal region as the domain responsible for the transcription inhibition specificity of the wild type T7 and K11 lysozymes. Furthermore, we were able to develop a simple and rapid purification scheme in purifying both the wild-type and chimeric lysozymes.

• Korean Journal of Microbiology
• /
• v.32 no.1
• /
• pp.70-77
• /
• 1994

The author isolated 7 mutant candidates which mapped around cysA (which was 10 o'clock). They were divided into two groups. One of them was located counterclockwise to cysA, and the other was clockwise to cysA. Since bldA was mapped counterclockwise to cysA, the candidate which mapped counterclockwise to cysA was transduced with phage containing wild type bldA gene clone. The candidates might be the alleles of bldA, because they were complemented by bldA clone. However some of such mutants sporulated very well and developed as much pigment as wild type on rich media plate. Their phenotype was not like bld mutant at all on such conditions. There were real antibiotics gene expressions, since transcriptional reporter gene xylE had shown high activities. Majority of the bldA like mutants showed act gene expressions when they were transformed with high copy number plasmid containing actII-ORF4.

• Journal of Microbiology
• /
• v.33 no.2
• /
• pp.160-164
• /
• 1995

The splicing activity of T4 phage td intron RNA has been examined with various Mg$^{2+}$ ions such as MGCl$_{2}$, MgS $O_{4}$ and magnesium acetate using various splicing conditions such as different incubation time and temperature. The maximum splicing of td intron RNA occurred at the concentration of 5 mM MgCl$_{2}$. Raising the Mg$^{2+}$ concentration up to 15 mM appeared to promote P2 delection mutant to overcome the loss of some splicing activity. In both wild type and mutant, a complete hydrolysis of RNA occurred at 30 mM MgCI$_{2}$ MgS $O_{4}$ and magnesium acetate exhibited the rate and pattern of RNA splicing identical to MGCI$_{2}$. The optimal splicing conditions involve the incubation of RNA with 5 mM MgCI$_{2}$ at 58 .deg.C for 15 min. The results suggest that Mg$^{2+}$ may play a key role in the catalytic mechanism of td intron RNA.n RNA.

• Molecules and Cells
• /
• v.21 no.2
• /
• pp.244-250
• /
• 2006

Gangliosides are receptors for various peptides and proteins including neuropeptides, ${\beta}$-amyloid proteins, and prions. Recently, the role of gangliosides in mucosal immunization has attracted attention due to the emerging interest in oral vaccination. Ganglioside GM1 exists in abundance on the surface of the M cells of Peyer's patch, a well-known mucosal immunity induction site. In the present study we identified a peptide ligand for GM1 and tested whether it played a role in immune induction. GM1-binding peptides were selected from a phage-displayed dodecapeptide library and one peptide motif, GWKERLSSWNRF, was fused to the C-terminus of enhanced green fluorescent protein (EGFP). The fusion protein, but not EGFP fused with a control peptide, was concentrated around Peyer's patch after incubation in the lumen of the intestine ex vivo. Furthermore, oral feeding of the fusion protein but not control EGFP induced mucosal and systemic immune responses against EGFP resembling Th2-type immune responses.

• Journal of Microbiology
• /
• v.43 no.5
• /
• pp.424-429
• /
• 2005

In previous studies, it has been reported that both S. enteritidis, the most common serotype, and S. enteritidis Phage Type 4 (SEPT 4) isolates were identified as the most prevalent PT in domestic poultry and also in humans in Korea until 2002. The aim of this study was to analyze the genetic diversity and epidemiological properties of both PT isolates, and also to trace the source of SEPT 4 isolates from domestic poultry and humans by Pulsed-field gel electrophoresis (PFGE). In order to understand the molecular epidemiologic properties of SEPT 4 isolates, which have very similar phenotypic properties to our preliminary investigations (serotyping, phage typing, large plasmids and antibiograms), PFGE analysis with XbaI enzyme was performed on the representative SEPT 4 isolates. Thirty-six SEPT 4 isolates were analyzed and differentiated with 10 pulsed-field profiles (PFP) expressing very high discriminative ability (SID: 0.921). In PFP, SEPT 4 isolates from human patients showed a perfect genetic match with those from broiler chickens and meats. Therefore, this study was able to successfully trace the major source of SEPT 4 isolates and also to determine the usefulness of the PFGE method for genetic analysis of epidemic strains.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1988.10a
• /
• pp.43-48
• /
• 1988

This paper provides readers with an attempt In applying expert systems to structural engineering. As a demonstrative domain to provide the pontentiality of expert system foundation design is presented. Foundation design can have less formalized phage in the overall design process, particularly during preliminary design. It depends on several factors: the function of the structure and the loads it must carry the subsurface conditions, and the cost of foundation, The expert system in the paper is to be used for determining the type of foundation.

• BMB Reports
• /
• v.38 no.1
• /
• pp.97-103
• /
• 2005

Under the condition of expression of $\lambda$ P protein at lethal level, the oriC DNA-binding activity is significantly affected in wild-type E. coli but not in the rpl mutant. In purified system, the $\lambda$ P protein inhibits the binding of both oriC DNA and ATP to the wild-type DnaA protein but not to the rpl DnaA protein. We conclude that the $\lambda$ P protein inhibits the binding of oriC DNA and ATP to the wild-type DnaA protein, which causes the inhibition of host DNA synthesis initiation that ultimately leads to bacterial death. A possible beneficial effect of this interaction of $\lambda$ P protein with E. coli DNA initiator protein DnaA for phage DNA replication has been proposed.