Biomedical subjects

Dong-Sik Shin

Publications and source records attributed to Dong-Sik Shin.

4 recordsLinked to original sources

PubMed2006

Selection of peptides for lipopolysaccharide binding on to epoxy beads and selective detection of Gram-negative bacteria.

Lipopolysaccharide (LPS)-binding peptides were enriched by using epoxy beads as a novel support to immobilize LPS for a phage displayed peptide library screening. The sequence of Phe-Ala-Pro-Trp (FAPW) was the most significant consensus motif of 10 selected clones, and Pro-Phe (PF) was the key dipeptide for binding at the apex of the loop to form a characteristic structure of CXXPFXXXC. Moreover, AWLPWAK, one of the highly conserved heptamer peptides, could detect specifically Gram-negative bacteria via a whole cell binding test at 10(6) cells ml(-1).

Bacterial Typing Techniques↗

PubMed2005

Combinatorial solid phase peptide synthesis and bioassays.

Solid phase peptide synthesis method, which was introduced by Merrifield in 1963, has spawned the concept of combinatorial chemistry. In this review, we summarize the present technologies of solid phase peptide synthesis (SPPS) that are related to combinatorial chemistry. The conventional methods of peptide library synthesis on polymer support are parallel synthesis, split and mix synthesis and reagent mixture synthesis. Combining surface chemistry with the recent technology of microelectronic semiconductor fabrication system, the peptide microarray synthesis methods on a planar solid support are developed, which leads to spatially addressable peptide library. There are two kinds of peptide microarray synthesis methodologies: pre-synthesized peptide immobilization onto a glass or membrane substrate and in situ peptide synthesis by a photolithography or the SPOT method. This review also discusses the application of peptide libraries for high-throughput bioassays, for example, peptide ligand screening for antibody or cell signaling, enzyme substrate and inhibitor screening as well as other applications.

Biological Assay↗

PubMed2005

Screening of LPS-specific peptides from a phage display library using epoxy beads.

The selection of identical or highly homologous peptides from phage display combinatorial peptide libraries has been unsuccessful in biopanning experiments using microtiter plates. In the present study, by biopanning on LPS-conjugated epoxy beads, we repeatedly enriched clones encoding AWLPWAK and NLQEFLF. These peptides were found to interact with the polysaccharide moiety of LPS, which is highly variable among gram negative bacterial species. In addition, phages encoding these peptides preferentially bound to the LPS of Salmonella family. AWLPWAK-conjugated beads absorbed Salmonella enteritidis from solution and showed a preference for S. enteritidis over Escherichia coli. In summary, this study shows for the first time that a peptide screened from phage displays of combinatorial peptide libraries can be synthesized on beads and be used practically to concentrate bacterial cells from solution.

Bacteriophages↗

PubMed2003

Protein patterning by maskless photolithography on hydrophilic polymer-grafted surface.

With the help of a microfabrication process and surface modification technology, a method of fabricating protein patterned chips was developed which can be utilized as a powerful tool for performing bioassays in a high-throughput manner. A digital micromirror array (MMA) system was used as a virtual photomask, so that a maskless photolithography process was able to be used to build patterned biomolecules on a chip by selective illumination onto the chip surface. We utilized the nitroveratryloxycarbonyl (NVOC) group as a photolabile protecting group for protein patterning. The NVOC-protected surface was selectively irradiated by a UV illuminator using an MMA. After removing the NVOC group, biotin was coupled to the NVOC-cleaved site, onto which a buffered streptavidin solution was eluted. At this point, we could obtain a streptavidin-patterned surface and observe the effect of the polymer-grafted surface in reducing nonspecific binding.

Adsorption↗