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)

Cystatin CsC, a cysteine proteinase inhibitor from chestnut (Castanea sativa) seeds, has been purified and characterized. Its full-length cDNA clone was isolated from an immature chestnut cotyledon library. The inhibitor was expressed in Escherichia coli and purified from bacterial extracts. Identity of both seed and recombinant cystatin was confirmed by matrix-assisted laser desorption/ionization mass spectrometry analysis, two-dimensional electrophoresis and N-terminal sequencing. CsC has a molecular mass of 11,275 Da and pI of 6.9. Its amino acid sequence includes all three motifs that are thought to be essential for inhibitory activity, and shows significant identity to other phytocystatins, especially that of cowpea (70%). Recombinant CsC inhibited papain (Ki 29 nM), ficin (Ki 65 nM), chymopapain (Ki 366 nM), and cathepsin B (Ki 473 nM). By contrast with most cystatins, it was also effective towards trypsin (Ki 3489 nM). CsC is active against digestive proteinases from the insect Tribolium castaneum and the mite Dermatophagoides farinae, two important agricultural pests. Its effects on the cysteine proteinase activity of two closely related mite species revealed the high specificity of the chestnut cystatin.
Plant Mol Biol 1998 Dec
PMID:A chestnut seed cystatin differentially effective against cysteine proteinases from closely related pests. 986 28

In the tropical species Carica papaya, the articulated and anastomosing laticifers form a dense network of vessels displayed in all aerial parts of the plant. Damaging the papaya tree inevitably severs its laticifers, eliciting an abrupt release of latex. Besides the well-known cysteine proteinases, papain, chymopapain, caricain and glycyl endopeptidase, papaya latex is also a rich source of other enzymes. Together, these enzymes could provide an important contribution to plant defence mechanisms by sanitising and sealing the wounded areas on the tree.
Cell Mol Life Sci 2001 Apr
PMID:Revisiting the enzymes stored in the laticifers of Carica papaya in the context of their possible participation in the plant defence mechanism. 1136 Oct 91

A barley cDNA clone encoding a cysteine proteinase inhibitor was characterized. The deduced amino acid sequence of this barley cystatin (Hv-CPI) contains the motif QXVXG conserved among members of the cystatin superfamily. The gene (Icy), located on chromosome 2, was expressed in embryos, developing endosperms, leaves and roots as assessed by northern blot analysis. Western blot analysis detected a slightly retarded band in leaves that was not present in roots or seeds. In these two organs a more precise location of Hv-CPI was done by immuno-histochemical analysis, with polyclonal antibodies raised against the recombinant CPI protein expressed in Escherichia coli. This protein efficiently inhibited papain (Ki 2.0 x 10(-8) M) and ficin (Ki 2.2 x 10(-8) M) and, to a lesser extent, chymopapain (Ki 1.6 x 10(-7) M) and was inactive against bromelain. The Icy mRNA expression in vegetative tissues increased in response to anaerobiosis, dark and cold shock (6 degrees C).
Plant Mol Biol 2001 Mar
PMID:A constitutive cystatin-encoding gene from barley (Icy) responds differentially to abiotic stimuli. 1141 18

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.
Mol Cell Proteomics 2005 May
PMID:High throughput substrate specificity profiling of serine and cysteine proteases using solution-phase fluorogenic peptide microarrays. 1570 70