Acetone Bromelain

Bromelain (anti-inflammatory Ananase from pineapple) [37189-34-7] Mr 33 000, [EC 3.4.33.4]. This protease has been purified via the acetone powder, G-75 Sephadex gel filtration and Bio-Rex 70 ion-exchange chromatography and has Aj 20.1 at 280nm. The protease from pineapple hydrolyses benzoyl glycine ethyl ester with a Km (app) of 210mM and kcat of 0.36 sec. [Murachi Methods Enzymol 19 273 1970 Balls et al. nd Eng Chem 33 950 1941.]... 

A family of cysteine proteinase inhibitors different from the cystatin super-family was Isolated from pineapple stem acetone powder. These inhibitors have a Mr of about 5800 and are composed of a longer (41 amino acids) and a shorter (1L ammo acids) peptide chain connected with disulfide bonds [29]. The conserved sequence Gin- fal-Val-AJa-Gly of the cystatins is not present in these inhibitors, indicating a different mechanism of interaction. The bromelain inhibitor VI was found to share similar folding and disulfide band connectivities with the Bowman-Bilk trypsiu/chymatrypsm inhibitor from soybean [30,31]. Hie physiological role of these inhibitors remains undear. 

Proteolytic activity in the juice of the pineapple plant Ananas comosus) was first reported in 1879 (7). More recently, the juice from the stem of the pineapple plant was shown to be a rich source of stem bromelain. This name is used to distinguish the enzyme from another which is derived from the fruit (8, 9). Mature pineapple stems are collected by special harvesting machines. The juice is pressed by special mills and then filtered. Most commercial preparations of bromelain have been precipitated from the stem juice by acetone. 

Although ficin has been commercially available for many years, it has not attained the importance of papain and bromelain. Ficin is imported mainly from South America where it is obtained from the latex of tropical fig trees of the genus Ficus. There are over 2000 species of this genus, and the amount of activity varies considerably from one species to another (10). Most of the commercial preparations of ficin are derived from F. glabrata. The latex is collected from the trees by tapping, and the juice separated after the latex has coagulated. The juice is then spray-dried, or the protein may be precipitated with acetone. 

An apparently homogeneous preparation of fruit bromelain can be prepared by acetone precipitation of the protein from the juice of the green or ripe fresh fruit followed by chromatography on DEAE-cellulose (38). 

Commercial bromelain is currently prepared by centrifugation, ultrafiltration and freeze-drying of cooled pineapple juice, which produces a yellowish powder. Stem bromelain has been generally prepared from the juice of pineapple wastes (mainly stems) by precipitation with organic solvents (e.g., acetone and methanol) or by ultrafiltration. ... 

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