Bromelain inhibitor VI is a double-chain inhibitor consisting of a 11-residue and a 41-residue chain. This protein is the 41-residue heavy chain which is joined to the 11-residue chain by disulphide bonds. The inhibitor acts to inhibit the cysteine proteinase bromelain [1].

1: Solution structure of bromelain inhibitor IV from pineapple stem: structural similarity with Bowman-Birk trypsin/chymotrypsin inhibitor from soybean. Hatano K, Kojima M, Tanokura M, Takahashi K; Biochemistry. 1996;35:5379-5384. PMID:8611527