摘要： This study aims to quantitatively investigate the interaction between sulfated polysaccharides with potent anti-HIV activity, dextran and curdlan sulfates with negatively charged sulfate groups, and poly-L-lysine as a model protein and oligopeptides from a HIV surface glycoprotein gp120 with positively charged amino acids using surface plasmon resonance (SPR) and dynamic light scattering (DLS) to elucidate the anti-HIV mechanism of sulfated polysaccharides. The apparent association- (ka) and dissociation rate (kd) constants of dextran and curdlan sulfates against poly-L-lysine were ka=6.92×104?2.17×106 1/Ms and kd=4.29×10-5? 2.22×10-4 1/s; these kinetic constants were dependent on the molecular weights and degree of sulfation of sulfated polysaccharides. For interaction, the three oligopeptides from the HIV gp120 were peptide A 297TRPNNNTRKRIRIQRGPGRA316 with several lysine (K) and arginine (R) in the V3 loop region, peptide B 493PLGVAPTKAKRRVVQREKR511 with several K and R in the C-terminus region, and oligopeptide C 362KQSSGGDPEIVTHSFNCGG380 with little basic amino acids in the CD4 binding domain. Sulfated polysaccharides exhibited strong interaction against oligopeptides A and B, (ka=5.48×104?2.96×106 1/Ms and kd=1.74×10-4?6.24×10-3 1/s), no interaction was noted against oligopeptide C. Moreover, the particle size and zeta potential by DLS indicated the interaction between sulfated polysaccharides and oligopeptides A and B, suggesting the anti-HIV mechanism of sulfated polysaccharides to be the electrostatic interaction of negatively charged sulfated polysaccharides and HIV at the positively charged amino acid regions.