EFFECTS OF ANIONIC AND NONIONIC POLYMERS ON FUSION AND BINDING OF SENDAI VIRUS TO HUMAN ERYTHROCYTE-GHOSTS

Effects of various polymers (dextran sulfate, dextran and polyethylene glycol) on binding and fusion of Sendai virus to target cells were st udied by use of fluorescence spectroscopy. Direct binding of dextran s ulfate but not dextran to Sendai virus was detected. Anionic and nonio nic polymers showed definite effects on segmental motions of the viral envelope proteins. Sendai virus binding to human erythrocyte ghost me mbranes (HEG) was reduced by dextran sulfate and dextran while the fus ion temperature dependence remained unaltered at approximate to 20 deg rees C. Nonionic polymer, polyethylene glycol, caused an increase in e xtent of fusion of Sendai virus with HEG. Segmental motion of viral en velope proteins, determined in terms of anisotropy of fluorescent prob es attached to viral surface proteins, exhibited a temperature depende nt transition at 20 degrees C by a sharp change from restricted to les s restricted motion. In the presence of each of the polymers, this tra nsition was no longer apparent. Since fusion did occur in the presence of all polymers, the temperature dependent characteristic of Sendai v irus target cell fusion can be said not to depend on viral surface pro tein segmental motion. A reasonable and coherent explanation was given for the apparent disparity between the effects of inhibiting and enha ncing polymers on fusion and motion of viral proteins. (C) 1998 Elsevi er Science B.V. All rights reserved.