Ogasawara K, Mazda T, Shimizu M
Blut. 1987 Jan;54(1):51-5. doi: 10.1007/BF00326028.
Human sera contain bromelin inhibitors in irregular antibody screening techniques. In order to identify and purify these inhibitors, pooled human sera were precipitated with ammonium sulfate, followed by DEAE-cellulose and Sephadex G-150 column chromatography. Proteinase activity and inhibitory activity to bromelin were observed in two protein fractions, these were identified as alpha 2-macroglobulin and the S-2 thiol proteinase inhibitor.