“…In the case of the tripeptide analogue (116-118), it has been proposed that this prevents fusion by competing with the fusion protein for a cellular receptor (Richardson et al, 1980). However, escape mutants that resist the effect of the tripeptide were found to possess mutations in the cysteine-rich region of MV F (Hull et al, 1987), which we have shown to be the site of interaction with the MV HA (T. F. Wild et al, 1994). This suggests that rather than having a direct effect on fusion, the tripeptide disrupts the F-HA interaction known to be a prerequisite for MV fusion (T. F. Wild et al, 1994).…”