Use of surface-enhanced Raman spectroscopy for the detection of human integrins.

Current research has revealed the importance of a class of cell surface proteins called integrins in various vital physiological functions such as blood clotting, regulation of blood pressure, tissue blood flow, and vascular remodeling. The key to integrin functionality is its ability to mediate force transmission by interacting with the extracellular matrix and cytoskeleton. In addition, they play a role in signal transduction via their connection with the proteins in focal adhesion (FA) points. To understand the complex mechanism of cell-cell and cell-extracellular matrix (ECM) adhesion that is responsible for these diverse biochemical interactions, it is necessary to identify the integrins on cells and monitor their interaction with various ligands. To this end, for the first time, we employ surface-enhanced Raman spectroscopy (SERS) to detect integrins. The results show the capability using SERS to detect the integrins to the nanomolar concentration regime and to distinguish between two different kinds of integrins, alphaVbeta3 and alpha5beta1, that are present in vascular smooth muscle cells (VSMCs). It is anticipated that the SERS approach will potentially help elucidate the mechanism of integrin-ligand interactions in a variety of phenomena of physiological importance.