Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.6 (chymopapain)
 407 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two forms of stem bromelain (EC 3.4.22.4) were isolated from commercial, crude and chromatographically purified preparations of the enzyme by means of gel-filtration and cation-exchange liquid chromatography. These forms possess nearly identical secondary and tertiary structures, as judged from their circular dichroism (c.d.) spectra. The spectral characteristics of stem bromelain suggest that this enzyme belongs to the alpha + beta protein class, as other cysteine proteinases do. In agreement with these results, quantitative estimation of secondary structures yielded amounts similar to those for papain and proteinase omega. However, the bromelain c.d. curve is clearly distinguishable from those reported for papain and proteinase omega, on one hand, and that of chymopapain, on the other. Thus, it is apparent that there are at least three types of c.d. spectra associated with the family of cysteine proteinases.
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PMID:Circular dichroism of stem bromelain: a third spectral class within the family of cysteine proteinases. 819 20

The amino acid sequences of ananain (EC3.4.22.31) and stem bromelain (3.4.22.32), two cysteine proteases from pineapple stem, are similar yet ananain and stem bromelain possess distinct specificities towards synthetic peptide substrates and different reactivities towards the cysteine protease inhibitors E-64 and chicken egg white cystatin. We present here the complete amino acid sequence of ananain and compare it with the reported sequences of pineapple stem bromelain, papain and chymopapain from papaya and actinidin from kiwifruit. Ananain is comprised of 216 residues with a theoretical mass of 23464 Da. This primary structure includes a sequence insert between residues 170 and 174 not present in stem bromelain or papain and a hydrophobic series of amino acids adjacent to His-157. It is possible that these sequence differences contribute to the different substrate and inhibitor specificities exhibited by ananain and stem bromelain.
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PMID:Complete amino acid sequence of ananain and a comparison with stem bromelain and other plant cysteine proteases. 935 53

Proteases regulate numerous biological processes with a degree of specificity often dictated by the amino acid sequence of the substrate cleavage site. To map protease/substrate interactions, a 722-member library of fluorogenic protease substrates of the general format Ac-Ala-X-X-(Arg/Lys)-coumarin was synthesized (X=all natural amino acids except cysteine) and microarrayed with fluorescent calibration standards in glycerol nanodroplets on glass slides. Specificities of 13 serine proteases (activated protein C, plasma kallikrein, factor VIIa, factor IXabeta, factor XIa and factor alpha XIIa, activated complement C1s, C1r, and D, tryptase, trypsin, subtilisin Carlsberg, and cathepsin G) and 11 papain-like cysteine proteases (cathepsin B, H, K, L, S, and V, rhodesain, papain, chymopapain, ficin, and stem bromelain) were obtained from 103,968 separate microarray fluorogenic reactions (722 substrates x 24 different proteases x 6 replicates). This is the first comprehensive study to report the substrate specificity of rhodesain, a papain-like cysteine protease expressed by Trypanasoma brucei rhodesiense, a parasitic protozoa responsible for causing sleeping sickness. Rhodesain displayed a strong P2 preference for Leu, Val, Phe, and Tyr in both the P1=Lys and Arg libraries. Solution-phase microarrays facilitate protease/substrate specificity profiling in a rapid manner with minimal peptide library or enzyme usage.
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PMID:High throughput substrate specificity profiling of serine and cysteine proteases using solution-phase fluorogenic peptide microarrays. 1570 70

We examined the mechanism of action and compared the anthelmintic efficacy of cysteine proteinases from papaya, pineapple, fig, kiwi fruit and Egyptian milkweed in vitro using the rodent gastrointestinal nematode Heligmosomoides polygyrus. Within a 2 h incubation period, all the cysteine proteinases, with the exception of the kiwi fruit extract, caused marked damage to the cuticle of H. polygyrus adult male and female worms, reflected in the loss of surface cuticular layers. Efficacy was comparable for both sexes of worms, was dependent on the presence of cysteine and was completely inhibited by the cysteine proteinase inhibitor, E-64. LD50 values indicated that the purified proteinases were more efficacious than the proteinases in the crude latex, with purified ficin, papain, chymopapain, Egyptian milkweed latex extract and pineapple fruit extract containing fruit bromelain, having the most potent effect. The mechanism of action of these plant enzymes (i.e. an attack on the protective cuticle of the worm) suggests that resistance would be slow to develop in the field. The efficacy and mode of action make plant cysteine proteinases potential candidates for a novel class of anthelmintics urgently required for the treatment of humans and domestic livestock.
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PMID:Assessment of the anthelmintic effect of natural plant cysteine proteinases against the gastrointestinal nematode, Heligmosomoides polygyrus, in vitro. 1572 70

An extracellular cysteine protease inhibitor (ECPI-2) was purified to homogeneity from the culture filtrate of Chlorella sp. 4533 by the combination of various column chromatographies. The molecular mass of the inhibitor was estimated to be 340 kDa by SDS-PAGE. The inhibitor was extremely heat-stable under acidic or neutral condition. ECPI-2 exhibited an inhibitory activity against the proteolytic activity of papain, ficin, or chymopapain, but not against stem bromelain or cathepsin B. The inhibitor showed no inhibitory activity against trypsin, alpha-chymotrypsin or thermolysin. ECPI-2 contains 33.6% carbohydrate residues by weight and inhibits papain at a molar ratio of 1:2. The proteolysis of the inhibitor by trypsin or alpha-chymotrypsin was apparent, but the inhibitory activity of ECPI-2 was unaffected by these enzymes. The alpha-chymotrypsin hydrolysis product from ECPI-2 was further separated into six fractions by gel filtration. From these results, it is suggested that ECPI-2 has several reactive sites for papain.
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PMID:Purification and characterization of extracellular cysteine protease inhibitor, ECPI-2, from Chlorella sp. 1656 14

The Proton Inventory (PI) method has been applied in the hydrolysis of synthetic substrates by papain, chymopapain and stem bromelain, comparing also their corresponding pH-(k(cat)/K(m)) profiles, and it was found: (a) k(cat)/K(m)=k(1), and thus K(S)=k(2)/k(1) is a dynamic equilibrium constant, (b) bowed-downward PI for k(cat)/K(m) exhibiting large inverse SIE, and (c) linear PI exhibiting large normal SIE for K(S), k(2) and k(3). A novel finding of this work is that the association of substrates onto all three studied cysteine proteinases proceeds via a stepwise pathway, in contrast to purely concerted pathways found previously for both acylation and deacylation. A hydrogen bond, which seems more likely to be developed across a pK(a)-value close to 4.00, connecting [see text] (papain/chymopapain or bromelain numbering), constitutes another novelty of this work.
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PMID:The catalytic mode of cysteine proteinases of papain (C1) family. 1699 46