Bromelain from pineapple stem

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. 

K. Hatanc, M. Kqjima, M. Tanokura, and K, Takahaihi. Solution structure of bromelain inhibitor VI from pineapple stem structural similarity with Bawmnn-Birk hyprin/chymotrypsin inhibitor from soybean. Biochemistry J5 5379 (1996). 

Bromelain is a mixture of cysteine proteases obtained from pineapple stems (Ananas comosus, Bromeliaceae) that has been used therapeutically for the treatment of inflammation and trauma [119]. 7n vitro, it has varied stimulatory effects on leukocyte populations, increases CD2-mediated T cell activation, enhances Ag-independent binding to monocytes, etc. The effects of bromelain have previously been attributed to its degradative action at cell surfaces. However, it also acts independent of the removal of cell surface molecules [120]. In order to investigate the possible hormonelike effects of bromelain on intracellular signalling, its effects on TCR7CD3 signalling and IL-2 production were studied. It was observed that bromelain inhibits ERK-2 activation in ThO cells stimulated via the TCR, or with combined TPA plus calcium ionophore. In addtion, bromelain decreased IL-2, IFN-y, and IL-4 mRNA accumulation in ThO cells stimulated with TPA plus calcium ionophore, while the cytokine mRNA accumulation in cells stimulated via TCR was not affected. It seems that bromelain does not act on ERK-2 directly but also inhibits p2r activation, an effector molecule upstream from ERK-2 in the Raf-1/MEKl/ERK kinase cascade. Since p21 is an effector for multiple MAPK pathways, it is likely that bromelain affects other MAPK signalling cascades, such as the INK pathway or p38 MAPK pathway [121],... 

L-aspartic acid involved in the glycopeptide linkage, i.e. cannot act on glyco-peptides with several amino-acid residues, a new amidase which overrides these requirements has been discovered in almond emulsin. The enzyme was shown to cleave the glycopeptide linkage in the glycopeptide (16) from pineapple-stem bromelain. 

Crude bromelain contains proteinases mainly consisting of glycosylated multiple enzymes having molecular masses from 20 to 31 kDa. Pineapple fruit contains fruit bromelain and pineapple stem contains stem bromelain, ana-nain, and comosain. It also contains various... 

Another subclass of proteases attacks internal peptide bonds and Hberates large peptide fragments. Bromelain, a plant protease derived from the stem of the pineapple plant, can even produce detectable semm proteolysis after oral adrninistration (180). Oral therapy with bromelain significantly reduces bmising that stems from obstetrical manipulations (181). Bromelain—pancreatin combinations have been more effective in digestive insufficiency compared to either pancreatin or placebo (182,183). Bromelain may also enhance the activity of antibiotics, especially tetracycline, when adrninistered concurrently (184). 

R. M. Hdnicke and W. A. Gortner. Stem bromelain, a nrar protease preparation from pineapple plants. Econ. Hot. 11 225 (1957). 

Enyzmes are present in all plant cells, and in greatest variety in seeds. Most plant enzymes are intracellular as they cannot diffuse through the cell wall. In a few cases the enzyme can be obtained from the plant juice, for example, the enzyme bromelain can be obtained from the stem of the pineapple. Otherwise, methods of extraction are used which depend on the rupturing of the cell wall, for example, grinding the plant with sand, either with or without freezing, or drying of the tissue. 

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. 

M. Fukuda, T. Kondo, and T. Osawa. Studies on the hydrazinolysis of glycoproteins. Core structures of oligosaccharides obtained from porcine thyroglobulin and pineapple stem bromelain. J. Biochem. 80 1223 (1976). 

Three other plant enzymes, papain, bromelain, and to a lesser extent ficin, have found acceptance in the food industry as proteases. Papain is derived from the latex of the fruit, leaves, and trunk of Carica papaya, and bromelain from the fruit and stems of pineapple plants. These enzymes are used to prevent the hazing of beer when chilled (Chill-Proofing) by modifying the protein. Other applications for these plant proteases are in meat tenderizers and digestive aids. Ficin from the latex of Ficus carica is used to a much lower extent, perhaps because of its marked action on native protein and difficult handling. Proteases from Aspergillus Jlavus-oryzae, and to a lesser extent from Bacillus subtilis, have been used to replace and supplement these plant proteases in all applications, but papain continues to have the widest acceptance. 

There appears to be sequence homology between the pineapple stem bromelain inhibitors and some of the small molecular weight inhibitors from the legumlnosae (91) Human inter-a-trypsin inhibitor contains two domains with great similarity to the domains of the Kunitz-type inhibitors (44 92-94)> The ovoinhibitors from Japanese quail and chicken egg whites contain six tandem domains which are homologous to the Kazal pancreatic secretory inhibitor and to the ovomucoids (69) ... 

Proteases such as a-chymotrypsin, papain, and subtilisin are also useful for regioselective hydrolytic transformations (Scheme 2.40). For example, while regio-selective hydrolysis of a dehydroglutamate diester at the 1-position can be achieved using a-chymotrypsin, the 5-ester is attacked by the protease papain [260]. It is noteworthy that papain is one of the few enzymes used for organic synthetic transformations which originate from plant sources (papaya). Other related protease preparations are derived from fig (ficin) and pineapple stem (bromelain) [261]. 

Bromelain (EC 3.4.22.4) a thiol enzyme from the stems and fruit of the pineapple plant. The stem enzyme is a basic glycoprotein (M, 33,000, pi 9.55) structurally and catalytically similar to papain. B. is activated by mercaptoethanol and other SH compounds, and it is irreversibly inhibited by reagents that block SH groups. It is an endopeptidase, and it is used in protein chemistry to hydrolyse polypeptide chains into large fragments. 

Bromelains are sulfhydryl proteolytic enzymes obtained from the pineapple plant, a perennial herb with many varieties native to tropical America. Two kinds of bromelain are known stem bromelain and fruit bromelain, which are crude aqueous extracts of the stem and immature fruit of pineapple... 

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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