Biomedical subjects

Young Je Yoo

Publications and source records attributed to Young Je Yoo.

6 recordsLinked to original sources

PubMed2005

Development of a protein microarray using sequence-specific DNA binding domain on DNA chip surface.

A protein microarray based on DNA microarray platform was developed to identify protein-protein interactions in vitro. The conventional DNA chip surface by 156-bp PCR product was prepared for a substrate of protein microarray. High-affinity sequence-specific DNA binding domain, GAL4 DNA binding domain, was introduced to the protein microarray as fusion partner of a target model protein, enhanced green fluorescent protein. The target protein was oriented immobilized directly on the DNA chip surface. Finally, monoclonal antibody of the target protein was used to identify the immobilized protein on the surface. This study shows that the conventional DNA chip can be used to make a protein microarray directly, and this novel protein microarray can be applicable as a tool for identifying protein-protein interactions.

Base Sequence↗

PubMed2005

Development of a plasmid display system using GAL4 DNA binding domain for the in vitro screening of functional proteins.

A plasmid display system using GAL4 DNA binding domain (GAL4 DBD) was constructed to enrich the molecular diversity and in vitro selection of functional proteins. Model proteins used were enhanced green fluorescent protein (EGFP) and glutathione S-transferase (GST). The feasibility of this display system was examined using enrichment experiments of target protein from a model protein mixture and identifying the encoding genes by PCR, in which the model protein mixture includes GAL4 DBD/GST fusion protein, GAL4 DBD/EGFP fusion protein, and xylanase. Target proteins of GAL4 DBD/GST and GAL4 DBD/EGFP from the model protein mixture were efficiently isolated by the plasmid display, respectively. The results show that the display system is sufficiently sensitive to select a target protein from a protein mixture, and that it is possible to discover the functional proteins from large libraries using relatively simple approaches.

Cloning, Molecular↗

PubMed2005

Environmental effects and desorption characteristics on heavy metal removal using carboxylated alginic acid.

Effects of ionic strength and organic materials on copper ion uptake capacity using carboxylated alginic acid which showed very high metal ion uptake capacity were investigated. The ionic strength only had a slight effect on the decrease of copper ion uptake capacity regardless of NaCl concentration. And, the effect of organic materials such as NTA (nitrilotriaceticacid) and sodium hypophosphite on the copper ion uptake capacity was negligible. When the lead ion adsorbed on carboxylated alginic acid was desorbed by NTA, which showed high desorption efficiency, the best optimum concentration of NTA was about 0.01 M. Also desorption efficiency decreased, however, concentration factor increased as S/L ratio which is defined as the ratio of adding amount of adsorbed and volume of desorbing agent increased. In sequential adsorption and desorption cycles, the lead uptake capacity on carboxylated alginic acid was relatively maintained through cycles 1-5.

Adsorption↗

PubMed2005

Packing-based difference of structural features between thermophilic and mesophilic proteins.

Twenty pairs of thermophilic and mesophilic proteins were compared in terms of residue packing distribution to obtain structural features related to protein thermostability. Based on residue packing concept, structural features of residues such as residue packing distribution, inner/outer position, secondary structure and water solvation were investigated. The statistical tests revealed that higher frequency in well-packed state of residues, lower frequency in exposed state and higher frequency in well-packed state of inner positioned residues, and higher frequency in well-packed state of 3/10 helix residues could be general structural features thermophilic proteins have.

Archaeal Proteins↗

PubMed2004

Protein thermostability: structure-based difference of amino acid between thermophilic and mesophilic proteins.

Structural distributions of each amino acid were compared between 20 pairs of thermophilic and mesophilic proteins to obtain thermostable factors. Five kinds of residual structure states such as fully-exposed, exposed, partially exposed (or partially buried), buried, well-buried states were considered for analyzing the structural patterns of amino acids. The statistical tests revealed that lower frequency in partially exposed state of SER, lower frequency in exposed state and higher frequency in well-buried state of ALA, higher frequency in buried state of GLU, higher frequency in exposed state of ARG, etc. could be critical factors related with protein thermostability.

Amino Acid Sequence↗

PubMed2002

Characteristics of metal removal using carboxylated alginic acid.

Carboxylated alginic acid prepared through oxidation reaction with potassium permanganate had a high uptake capacity of 3.1 mmol/g dry mass at pH 4 and showed higher affinity to heavy metals compared to alkaline metals (Ca2+, Mg2+) in mixed metal system. The pHzpc value of the carboxylated alginic acid was 2.31, which was lower than pHzpc (2.83) of natural alginic acid. The increased number of carboxyl groups was confirmed by IR and 13C-NMR spectrum analysis, elemental analysis and carboxyl group number count. Lead adsorption by carboxylated alginic acid is an endothermic process since binding was increased as the temperature increased. When the temperature of wastewater is higher than room temperature, carboxylated alginic acid has an advantage over general adsorbents whose uptake capacity decreases as the temperature increases. Also, lead adsorbed on carboxylated alginic acid was desorbed effectively by about 80% by nitrilotriaceticacid.

Alginates↗