Protein-digesting and milk-clotting enzymes found in pineapple fruit juice and stem tissue. Enzymes from the two sources are distinguished as fruit bromelain and stem bromelain. First isolns of fruit bromelain: Marcano, Bull. Pharm. 5, 77 (1891); Chittenden, Trans. Conn. Acad. Sci. 8, 281 (1892). From pineapple juice by precipitation with acetone and also with ammonium sulfide: Heinicke, US 3002891 (1961 to Pineapple Res. Inst.). Discovery in stem tissue: idem, Science 118, 753 (1953). Stem bromelain has mol wt of about 33,000 and is probably the first proteolytic enzyme of plant origin to be established as a glycoprotein: Murachi et al., Biochemistry 3, 48 (1964); Ota et al., ibid. 180. Purification of crude prepns: Gibian, Bratfisch, US 2950227 (1960 to Schering AG). Reviews: Balls et al., Ind. Eng. Chem. 33, 950 (1941); of stem bromelain: Murachi, “Structure and Function of Stem Bromelain,” in Proteins, Structure and Function vol. 2, M. Funatsu et al., Eds. (Kodansha, Tokyo, Wiley, New York, 1972) pp 47-101.
Anti-inflammatory.