RESUMEN
<p><b>OBJECTIVE</b>To study the targeted point and mechanism of the function of the blood-activating and stasis-removing Chinese drugs, Paeoniae Radix 801(PR801) in its cardiovascular protective effects and its specific binding with endothelin 1 (ET-1) as well as the dynamics of the two's interactive function by means of using affinity biosensors: IAsys Plus and quartz crystal microbalance (IAQCM).</p><p><b>METHODS</b>ET-1 was immobilized on the surfaces of IAQCM by using the new surface modification methods. The PR801 in the solution was detected by modified substrates and the specific binding between PR801 and ET-1 was studied.</p><p><b>RESULTS</b>The curves went up or down after adding PR801. There is specific binding between PR801 and ET-1. The bound mass were 0.458 ng/mm(2) and 133.54 ng/cm(2), respectively. There exists relatively good stability with these two methods.</p><p><b>CONCLUSION</b>The affinity biosensors: IAQCM can be used to study the interaction mechanism between PR801 and ET-1, providing a new way to study the interaction mechanism of TCM. PR801 can bind ET-1 specifically in the experiments. Therefore, ET-1 is another target that PR801 can bind specifically besides thromboxane A(2).</p>