Examination of cell surface proteins in the process of hES cell differentiation

COLL 167

Dengli Qiu1, Jialing Xiang1, and Rong Wang, wangr@iit.edu2. (1) Department of Biological, Chemical, and Physical Sciences, Illinois Institute of Technology, 3101 S. Dearborn Street, Chicago, IL 60616, (2) Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Life Sciences Building, 3101 Dearborn St., Chicago, IL 60616
Human embryonic stem (hES) cells hold great promise in regenerative medicine. Although hES cells have unlimited self-renewal potential, they tend to differentiate spontaneously in culture. Characterization of protein-protein interactions at the single cell level helps capture the initial stage of hES cell differentiation. As a proof-of-concept experiment, we utilized the atomic force microscopy (AFM) to monitor the hES cell differentiation process. Protein Tra-1-81 distribution and population on cell membranes were examined by affinity mapping, in which an antibody modified probe was used. It was found that the distribution of TRA-1-81 antigen is heterogeneous with a population of ~8500 epitopes per cell on undifferentiated cells, and is homogeneous with a population of < 500 epitopes per cell on differentiated cells. The interaction between a pair of TRA-1-81 antigen-antibody is estimated at 140-180 pN. At the areas containing high density of TRA-1-81 antigen, closely associated pairs of epitopes were frequently observed.
 

Fundamental Research in Colloid and Surface Chemistry
6:00 PM-8:00 PM, Monday, April 7, 2008 Morial Convention Center -- Rm. 244/245, Poster

Division of Colloid & Surface Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008