Respiratory syncytial virus (RSV) G glycoprotein mediates cell attachment through surface glycosaminoglycans (GAGs). Feldman et al.  suggested that specific basic amino acids in residues 184-198 of G defined a critical heparin binding domain (HBD). To further define the G HBD we made a series of truncated G proteins expressed in Escherichia coli. G88 (G residues 143-231), bound to HEp-2 cells in a dose dependent manner and binding was inhibited >99 with heparin. Cell binding of G88 was unaltered by alanine substitution mutagenesis of all basic amino acids in Feldman s region 184-198. A G88 variant truncated beyond residue 198, G58, and G58 fully alanine substituted in the region 184-198, G58A6, bound to HEp-2 cells about half as well and 100-fold less well than G88, respectively. G88 and all alanine substitution mutants of G88 inhibited RSV plaque formation by 50 (ID(50)) at concentrations of approximately 50 nM; the ID(50) of G58 was approximately 425 nM while G58A6 had an ID(50) >1600 nM. These data show that the G HBD includes as much as residues 187-231, that there is redundancy beyond the previously described HBD, and that the cell-binding and virus infectivity-blocking functions of these recombinant G proteins were closely linked and required at least one HBD.
|Pages (from-to)||1987 - 2003|
|Number of pages||17|
|Journal||Archives of Virology|
|Publication status||Published - 2003|