Biomedical subjects

Jong Pil Park

Publications and source records attributed to Jong Pil Park.

7 recordsLinked to original sources

PubMed2006

Protein nanopatterns and biosensors using gold binding polypeptide as a fusion partner.

An efficient strategy for immobilizing proteins on a gold surface was developed by employing the gold binding polypeptide (GBP) as a fusion partner. Using the enhanced green fluorescent protein (EGFP), severe acute respiratory syndrome coronavirus (SARS-CoV) envelope protein (SCVme), and core streptavidin (cSA) of Streptomyces avidinii as model proteins, specific immobilization of the GBP-fusion proteins onto the gold nanoparticles and generation of protein nanopatterns on the bare gold surface were demonstrated. The GBP-fused SCVme bound to gold nanoparticles successfully interacted with its antibody and showed changes in absorbance and color, allowing efficient diagnosis of SARS-CoV. The fusion proteins could be successfully immobilized on the gold surface by nanopatterning and microcontact printing as examined by atomic force microscopy and surface plasmon resonance analysis. The poly(dimethylsiloxane) microfluidic channels were created on the gold surface and were used for antigen-antibody and DNA-DNA interaction studies. Specific immobilization of GBP-EGFP fusion protein and its interaction with the antibody in the microchannels could be demonstrated. By immobilizing the DNA probe through the use of GBP-fused cSA, specific hybridization of the target DNA prepared from Salmonella could also be achieved. The GBP-fusion method allows immobilization of proteins onto the gold surface without surface modification and in bioactive forms suitable for studying protein-protein, DNA-DNA, and other biomolecular interaction studies. Furthermore, these studies can be carried out in a microfluidic system, which allows high-throughput analysis of biomolecular interactions.

Biological Assay↗

PubMed2005

Micropatterning proteins on polyhydroxyalkanoate substrates by using the substrate binding domain as a fusion partner.

A novel strategy for micropatterning proteins on the surface of polyhydroxyalkanoate (PHA) biopolymer by microcontact printing (microCP) is described. The substrate binding domain (SBD) of the Pseudomonas stutzeri PHA depolymerase was used as a fusion partner for specifically immobilizing proteins on PHA substrate. Enhanced green fluorescent protein (EGFP) and red fluorescent protein (RFP) fused to the SBD could be specifically immobilized on the micropatterns of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate). Laser scanning confocal microscopic studies suggested that two fusion proteins were micropatterned in their functionally active forms. Also, antibody binding assay by surface plasmon resonance suggested that protein-protein interaction studies could be carried out using this system.

Adsorption↗

PubMed2005

Selective immobilization of fusion proteins on poly(hydroxyalkanoate) microbeads.

A novel fusion protein system employing the substrate-binding domain (SBD) of poly(hydroxyalkanoate) (PHA) depolymerase was developed for the specific immobilization of proteins on PHA microbeads, and was consequently used for immunoassays. The enhanced green fluorescent protein, red fluorescent protein, and severe acute respiratory syndrome coronavirus envelope protein were used as model proteins, and were selectively and functionally immobilized to the PHA microbeads by fusing them to the SBD. Using this PHA microbead system combined with SBD fusion technology, immunoassays could be successfully carried out.

Flow Cytometry↗

PubMed2004

Micropatterns of spores displaying heterologous proteins.

Micropatterns of Bacillus thuringiensis spores were generated by a combination of surface chemistry, microcontact printing, and spore surface display technique. The outermost layers of B. thuringiensis spores were engineered to present enhanced green fluorescent protein (EGFP), and the biospecific interaction between biotin and streptavidin was utilized to spatially direct the EGFP-presenting spores onto the micropatterned surfaces. The viability of the micropatterned spores was confirmed by the pattern generation of vegetative cells after the germination.

Bacillus thuringiensis↗

PubMed2003

In silico prediction and validation of the importance of the Entner-Doudoroff pathway in poly(3-hydroxybutyrate) production by metabolically engineered Escherichia coli.

The metabolic network of Escherichia coli was constructed and was used to simulate the distribution of metabolic fluxes in wild-type E. coli and recombinant E. coli producing poly(3-hydroxybutyrate) [P(3HB)]. The flux of acetyl-CoA into the tricarboxylic acid (TCA) cycle, which competes with the P(3HB) biosynthesis pathway, decreased significantly during P(3HB) production. It was notable to find from in silico analysis that the Entner-Doudoroff (ED) pathway flux increased significantly under P(3HB)-accumulating conditions. To prove the role of ED pathway on P(3HB) production, a mutant E. coli strain, KEDA, which is defective in the activity of 2-keto-3-deoxy-6-phosphogluconate aldolase (Eda), was examined as a host strain for the production of P(3HB) by transforming it with pJC4, a plasmid containing the Alcaligenes latus P(3HB) biosynthesis operon. The P(3HB) content obtained with KEDA (pJC4) was lower than that obtained with its parent strain KS272 (pJC4). The reduced P(3HB) biosynthetic capacity of KEDA (pJC4) could be restored by the co-expression of the E. coli eda gene, which proves the important role of ED pathway on P(3HB) synthesis in recombinant E. coli as predicted by metabolic flux analysis.

Alcaligenes↗

PubMed2002

Metabolic engineering of Escherichia coli for the production of medium-chain-length polyhydroxyalkanoates rich in specific monomers.

The Escherichia coli fabG(Ec) gene and the Pseudomonas aeruginosa rhlG(Pa) gene, which encode 3-ketoacyl-acyl carrier protein reductase, were expressed in E. coli W3110 and its fadA mutant strain WA101 to examine their roles in medium-chain-length (MCL) polyhydroxyalkanoate (PHA) biosynthesis from fatty acids. When one of these 3-ketoacyl-acyl carrier protein reductase genes was co-expressed with the Pseudomonas sp. 61-3 PHA synthase gene (phaC2(Ps)) in E. coli W3110, MCL-PHA composed mainly of 3-hydroxyoctanoate and 3-hydroxydecanoate was synthesized from sodium decanoate. When the fabG(Ec) gene and the phaC2(Ps) gene were co-expressed in the fadA mutant E. coli strain WA101, MCL-PHA rich in 3-hydroxydecanoate monomer up to 93 mol% was accumulated from sodium decanoate. This was possible by efficiently redirecting 3-ketoacyl-coenzymes A from the beta-oxidation pathway to the PHA biosynthesis pathway without losing two carbon units, the strategy of which can be extended for the production of MCL-PHAs rich in other specific monomers.

3-Oxoacyl-(Acyl-Carrier-Protein) Reductase↗

PubMed2002

Purulent pericarditis caused by group G streptococcus as an initial presentation of colon cancer.

Bacterial pericarditis has been recognized as a rare disease since the development of antibiotics. Usually, the disease is associated with underlying conditions or a seeding of infection elsewhere to the pericardium. Here we describe a case of group G streptococcal pericarditis as an initial presentation of colon cancer. A 52-yr-old man was admitted because of dyspnea. An electrocardiogram showed a diffuse ST-segment elevation and a two-dimensional echocardiogram showed a large amount of pericardial effusion. A pericardiocentesis was done and purulent fluid was drained. Group G streptococci was cultured in pericardial fluid. The patient was treated with antibiotics and pericardiostomy with saline irrigation. A colonoscopy revealed a small mass with moderately differentiated adenocarcinoma in rectosigmoid colon. He underwent a mucosectomy and was recovered without any complication.

Adenocarcinoma↗