The Location of the Bromelain Cleavage Site in a Hong Kong Influenza Virus Haemagglutinin

Abstract

The site of bromelain cleavage in the hemagglutinin of the Hong Kong influenza virus A/Memphis/102/72 was determined using a diagonal peptide mapping procedure on the thermolytic digest of amidated BHA [truncated hemagglutinin obtained by bromelain digestion]. Bromelain cleavage removes the C-terminal 46 residues from HA2. The new C-terminal residue of BHA2 is Gly 175. This is close to the beginning of the hydrophobic membrane-interacting sequence that starts at residue 183.