The location of the bromelain cleavage site in a Hong Kong influenza virus Haemagglutinin.

The site of bromelain cleavage in the haemagglutinin of the Hong Kong influenza virus A/Memphis/102/72 has been determined by using a diagonal peptide mapping procedure on the thermolytic digest of amidated BHA. The data show that bromelain cleavage removes the C-terminal 46 residues from HA2, and that the new carboxyl-terminal residue of BHA2 is Gly 175. This is close to the beginning of the hydrophobic membrane-interacting sequence that starts at residue 183.