Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.22.25 (chymopapain)
 430 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acidic proteins tend to be degraded more rapidly than neutral or basic proteins in rat liver, skeletal muscle, kidney and brain and in mouse liver and skeletal muscle. We now report a similar relationship among soluble proteins from rat lung, heart and testes, and from human fibroblasts and mouse-embryo cells grown in culture. These findings indicate that the correlation between protein net charge and degradative rate is a general characteristic of intracellular protein degradation in mammals. This relationship between isoelectric point and half-life appears to be distinct from the previously reported correlation between subunit molecular weight and protein half-lives. The more rapid degradation of acidic proteins does not result from their being of larger molecular weight than neutral or basic proteins. Furthermore, proteins within specific isoelectric point ranges still exhibit a relationship between subunit size and half-life. Finally, a group of membrane or organelle-associated proteins that are insoluble in phosphate-buffered saline and water but soluble in 1% Triton X-100 exhibit a correlation between size and half-life, but not between net charge and half-life. The biochemical reasons for the relationship between protein isoelectric point and half-life are unclear, although several possible explanations are presented. It is not due to a greater sensitivity of acidic proteins to proteolytic attack since experiments with a variety of endoproteinases, including trypsin, chymotrypsin, Pronase, papain, chymopapain, Staphylococcus aureus V8 proteinase, pepsin and lysosomal cathepsins from rat liver, have failed to demonstrate more rapid digestion of acidic proteins.
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PMID:Studies on the relationship between the degradative rates of proteins in vivo and their isoelectric points. 3 75

Chromatography on a column of SP-Sephadex shows that commercial chymopapain contains three components with proteolytic activity. Each behaves as a single protein upon rechromatography and electrophoresis on polyacrylamide gels. The major component, which represents 31% of the activity applied to the column and is the most basic protein, was identified as papaya peptidase A. This enzyme has no methionine and isoleucine on its N-terminus. Its molecular weight is about 24,000 as determined by sodium dodecyl sulfate polyacrylamide electrophoresis and sedimentation equilibrium centrifugation. Its fluorescence emission as a function of pH resembles that for unactivated papain. Reduction is required for full activity, and in general it is less active than papain against substrates such as casein, N-benzoyl-L-arginine ethyl ester, N-tosyl-L-arginine methyl ester, N-benzoyl-L-arginineamide, and N-benzoyl-DL-arginine p-nitroanilide. Of the other components isolated from crude chymopapain, the more acidic enzyme contains 20% of the activity applied to the column, has a molecular weight of about 25,000, and N-terminal residues of tyrosine and glutamic acid. The other enzyme represents 26% of the initial activity, has a molecular weight of about 28,000 and tyrosine on its N-terminus. Both proteins have a single residue of methionine per molecule. The more acidic component resembles chymopapain A, and the other enzyme is similar to chymopapain B.
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PMID:Isolation and characterization of papaya peptidase A from commercial chymopapain. 24 Mar 90

Two proteases, one of which is papaya peptidase A and the other a previously unknown enzyme in papaya latex have been purified to homogeneity in a simple two stage process. Both are markedly less reactive than papain or chymopapain. Each has a molecular weight of 24,000, N-terminal sequences commencing Leu-Pro-Glu, and contains no carbohydrate. Their amino acid compositions differ for several residues. The essential -SH groups of the enzymes examined appear to be 'masked' in the native state.
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PMID:A purification and some properties of two proteases from papaya latex. 47 25

Sequences to residue 17 have been determined for the three Papaya cysteinyl proteases, chymopapain and papaya peptidase A and B. Extensive homologies were found for these three enzymes and with papain and bromelain. These results suggest that the five sulphydryl enzymes discussed derive from a common ancestral gene.
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PMID:N-Terminal homology in three cysteinyl proteases from Papaya latex. 51 21

Agglutination studies with 6 plant lectins indicated that the unaltered surface coat of Trypanosoma equiperdum isolated from rat blood lacks the carbohydrate molecules preferentially bound by these proteins. However, trypsin, pronase, chymopapain, or papain treatments exposed the binding sites for Concanavalin A and the phytohemagglutinins M and P and trypsinized cells were attached to Concanavalin A immobilized on agarose beads. Lipolytic, amylytic, and other proteolytic enzymes or other agents did not reduce or induce lectin agglutination and wheat germ, Anti A, and Anti H lectins did not clump the trypanosomes under any of the conditions employed. Carbohydrate residues resembling D-mannose or n-acetyl-D-galactosamine are therefore within the surface coat of T. equiperdum or on the cell membrane underneath it. The results are contrasted with the lectin induced agglutination of other parasite species and mammalian cells.
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PMID:Lectin binding by trypanosoma equiperdum. 84 43

A new model employing latex of papaya as an inflammagen has been developed for testing anti-inflammatory activity. The latex (exudate) was harvested from the unripe papaya fruit, which had been dried under vacuum. The latex was then suspended in 0.05 M sodium acetate buffer. This suspension when injected in rat hind paw produced concentration-dependent inflammation. Of the 0.25% of this suspension, 0.1 ml was found ideal for evaluating anti-inflammatory activity of test drugs. This concentration produced 70%-100% inflammation lasting for about 5 hr with a maximum effect at h 3. The test drugs employed were prednisolone, aspirin, indomethacin, phenylbutazone, ibuprofen, piroxicam, chloroquine, levamisole, and a mixture of boswellic acids. For comparison, these drugs were also tested against carrageenan-induced inflammation. All the test drugs--steroidal, aspirin, and non-aspirin-like--showed anti-inflammatory activity against latex-induced inflammation. The activity of chloroquine, levamisole, and boswellic acids was significantly more against latex as compared with that of the carrageenan model. The inflammation caused by latex may be attributed to both its hydrolytic enzymes--papain and chymopapain--and glutathione, the activator of these enzymes. These enzymes seem to act like lysosomal enzymes that are released in inflammatory disease processes which mediate inflammation by stimulating the synthesis of prostaglandins. The papaya latex-induced inflammation model appears to be a sensitive, broad-based, and relevant one likely to prove useful for discovering new and effective drugs against inflammation and rheumatoid arthritis.
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PMID:A sensitive and relevant model for evaluating anti-inflammatory activity-papaya latex-induced rat paw inflammation. 139 54

Sciatica caused by intervertebral disc herniation can be treated with intradiscal injection of chymopapain. A search for a cheaper and less allergizing product led to triamcinolone hexacetonide, this procedure being known as "nucleorthesis". The first results at 6 months were encouraging. In 3 centres where triamcinolone hexacetonide was tested with a more than 2 years' follow-up 92 patients could be evaluated. The results obtained were considered satisfactory in 34 patients (36.9 percent), but they were poor in 19 patients (20.6 percent), and 39 patients (42 percent) had to be operated upon within 2 years. Return to surgery took place within the 6 months following nucleorthesis in 18 patients (19.56 percent) and beyond this period in 17 patients (22.8 percent) with degradation of the results. Moreover, calcifications were found in 19 out of 38 patients; they were of varying size, sometimes detected only at computerized tomography, and some of them appeared to produce symptoms. All considered, the failure rates, the number of patients who required surgery and the occurrence of large and sometimes symptomatic calcifications make triamcinolone nucleorthesis unacceptable compared with the recognized percentages of success with papain nucleolysis and surgical operations. For these reasons, we consider that this treatment should be abandoned.
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PMID:[Unsatisfactory results of intradiscal injection of triamcinolone hexacetonide in the treatment of sciatica caused by intervertebral disk herniation]. 841 78

Two forms of proteinase omega were isolated from a commercial preparation of chymopapain (EC 3.4.22.6) by means of cation-exchange liquid chromatography. Their circular dichroism (CD) spectra in the 182-320 nm region indicated that the two forms possess closely related structures. For comparison, we also recorded the CD spectra of chromatographically purified samples of papain (EC 3.422.2) and the most abundant form of chymopapain. According to the qualitative criteria proposed by Manavalan and Johnson (1983) Nature 305, 831-832), the spectral characteristics of papain correctly indicate that this protein belongs to the alpha + beta class. Proteinase omega is also placed in the alpha + beta category, while chymopapain seems to be an alpha/beta protein. Quantitative estimation of secondary structures yielded contents of helices and parallel beta-sheet that were higher in the case of chymopapain. Thus, the results of this work suggest that there are some differences in the folding pattern of chymopapain with respect to the other two proteinases. This proposal seems unexpected when the high amino acid sequence identity among these enzymes is considered.
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PMID:Circular dichroism of cysteine proteinases from papaya latex. Evidence of differences in the folding of their polypeptide chains. 173 51

Chymopapain is a polypeptide of 218 amino acid residues. It has considerable structural similarity with papain and papaya proteinase omega, including conservation of the catalytic site and of the disulphide bonding. Chymopapain is like papaya proteinase omega in carrying four extra residues between papain positions 168 and 169, but differs from both papaya proteinases in the composition of its S2 subsite, as well as in having a second thiol group, Cys-117. Some evidence for the amino acid sequence of chymopapain has been deposited as Supplementary Publication SUP 50153 (12 pages) at the British Library Document Supply Centre, Boston Spa., Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms indicated in Biochem. J. (1990) 265, 5. The information comprises Supplement Tables 1-4, which contain, in order, amino acid compositions of peptides from tryptic, peptic, CNBr and mild acid cleavages, Supplement Fig. 1, showing re-fractionation of selected peaks from Fig. 2 of the main paper. Supplement Fig. 2, showing cation-exchange chromatography of the earliest-eluted peak of Fig. 3 of the main paper, Supplement Fig. 3, showing reverse-phase h.p.l.c. of the later-eluted peak from Fig. 3 of the main paper, and Supplement Fig. 4, showing the separation of peptides after mild acid hydrolysis of CNBr-cleavage fragment CB3.
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PMID:The amino acid sequence of chymopapain from Carica papaya. 210 78

The specificity of papaya proteinase IV (PPIV) has been examined with small substrates and a protein. With both classes of substrate, the enzyme shows a marked selectivity for cleaving glycyl bonds. Boc-Ala-Ala-Gly-NHPhNO2 is a convenient substrate for routine assays that discriminate well against chymopapain, the most common contaminant of PPIV. Sixteen cleavage points in beta-trypsin were identified, of which 13 are glycyl bonds. Tentative suggestions are made as to the reasons for lack of cleavage of some other glycyl bonds. The structure of PPIV has been modelled on that of papain, and we suggest that the replacement of the highly conserved residues Gly-65 and Gly-23 by arginine and glutamic acid, respectively, can account for the specificity of PPIV.
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PMID:Selective cleavage of glycyl bonds by papaya proteinase IV. 240 97


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