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Pohang, South Korea

Yoon J.W.,Pusan National University | Jang I.H.,Pusan National University | Heo S.C.,Pusan National University | Kwon Y.W.,Pusan National University | And 10 more authors.
PLoS ONE | Year: 2015

Endothelial progenitor cells (EPCs) can be isolated from human bone marrow or peripheral blood and reportedly contribute to neovascularization. Aptamers are 40-120-mer nucleotides that bind to a specific target molecule, as antibodies do. To utilize apatmers for isolation of EPCs, in the present study, we successfully generated aptamers that recognize human CD31, an endothelial cell marker. CD31 aptamers bound to human umbilical cord blood-derived EPCs and showed specific interaction with human CD31, but not with mouse CD31. However, CD31 aptamers showed non-specific interaction with CD31-negative 293FT cells and addition of polyanionic competitor dextran sulfate eliminated non-specific interaction without affecting cell viability. From the mixture of EPCs and 293FT cells, CD31 aptamers successfully isolated EPCs with 97.6% purity and 94.2% yield, comparable to those from antibody isolation. In addition, isolated EPCs were decoupled from CD31 aptamers with a brief treatment of high concentration dextran sulfate. EPCs isolated with CD31 aptamers and subsequently decoupled from CD31 aptamers were functional and enhanced the restoration of blood flow when transplanted into a murine hindlimb ischemia model. In this study, we demonstrated isolation of foreign material-free EPCs, which can be utilized as a universal protocol in preparation of cells for therapeutic transplantation. © 2015 Yoon et al. Source

The present invention relates to a method and detection kit for determining a presence of one or more proteins using aptamer-mediated pull-down assays. Specifically, a reproducible a protein precipitation (Co-AP/AP) method is provided to identify physiologically relevant protein-protein interactions by using target protein-specific aptamers, and to confirm its superior performance over antibody based protein precipitation (Co-IP/IP) methods in terms of its protein pull-down performance.

Kim K.,Aptamer science Inc. | Lee S.,Aptamer science Inc. | Ryu S.,Aptamer science Inc. | Ryu S.,Pohang University of Science and Technology | Han D.,Aptamer science Inc.
Biochemical and Biophysical Research Communications | Year: 2014

Protein precipitation is one of the most widely used methods for antigen detection and purification in biological research. We developed a reproducible aptamer-mediated magnetic protein precipitation method that is able to efficiently capture, purify and isolate the target proteins. We discovered DNA aptamers having individually high affinity and specificity against human epidermal growth factor receptor (EGFR) and human insulin receptor (INSR). Using aptamers and magnetic beads, we showed it is highly efficient technique to enrich endogenous proteins complex and is applicable to identify physiologically relevant protein-protein interactions with minimized nonspecific binding of proteins. The results presented here indicate that aptamers would be applicable as a useful and cost-effective tool to identify the presence of the particular target protein with their specific protein partners. © 2014 Elsevier Inc. All rights reserved. Source

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