FIG. 1.
Identification of Galla chinensis components that have a high affinity to the SARS S2 protein by MS coupled with frontal affinity chromatography. (a) Purity of the GST-S fusion protein as shown by SDS-15% PAGE. (b) The specific binding of the GST-S2 protein with sera of three convalescent SARS patients (P1, P2, and P3) as shown by ELISA. Two normal sera (N1 and N2) and GST were used as controls. (c) The mass spectra of the crude extract of Galla chinensis (the main components are numbered 1 to 10; also see Table 1). (d) Frontal affinity chromatographic traces (selected ion chromatogram from the mass spectra, Fig. 1c) of the 10 main components in Galla chinensis. V0 indicates the volume of the nonbinding small molecules. Note the high retention time (t1/2 = 85 min) of component 10, indicating an exceptionally strong binding affinity to the SARS S2 protein.