PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cysteine Endopeptidases”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1993

The inhibition of interleukin 1-stimulated cartilage proteoglycan degradation by cysteine endopeptidase inactivators.

Cysteine endopeptidase inactivators were tested as inhibitors of interleukin 1-stimulated proteoglycan release from bovine nasal septum cartilage explants. Hydrophilic inactivators showed no inhibition at concentrations up to 100 microM. In contrast, lipophilic inactivators gave significant inhibition, which was both reversible and specific. No effects on interleukin 1 signal transduction were detected, but rates of proteoglycan synthesis were apparently increased. Our results suggest that one or more of the lysosomal cathepsins B, L and S mediate cytokine-stimulated proteoglycan degradation, and the turnover of newly synthesized proteoglycan, but that effective inhibitors must pass through membranes.

Animals↗
PubMed1995

Crystal structure of glycyl endopeptidase from Carica papaya: a cysteine endopeptidase of unusual substrate specificity.

Glycyl endopeptidase is a cysteine endopeptidase of the papain family, characterized by specificity for cleavage C-terminal to glycyl residues only and by resistance to inhibition by members of the cystatin family of cysteine proteinase inhibitors. Glycyl endopeptidase has been crystallized from high salt with a substrate-like inhibitor covalently bound to the catalytic Cys 25. The structure has been solved by molecular replacement with the structure of papain and refined at 2.1 A to an R factor of 0.196 (Rfree = 0.258) with good geometry. The structure of the S1 substrate binding site of glycyl endopeptidase differs from that of papain by the substitution of glycines at residues 23 and 65 in papain, with glutamic acid and arginine, respectively, in glycyl endopeptidase. The side chains of these residues form a barrier across the binding pocket, effectively excluding substrate residues with large side chains from the S1 subsite. The constriction of this subsite in glycyl endopeptidase explains the unique specificity of this enzyme for cleavage after glycyl residues and is a major component of its resistance to inhibition by cystatins.

Amino Acid Sequence↗
PubMed1992

Inhibition of interleukin 1-stimulated cartilage proteoglycan degradation by a lipophilic inactivator of cysteine endopeptidases.

Inactivators of cysteine endopeptidases were tested as inhibitors of the cytokine-stimulated release of proteoglycan from cartilage. The test system consisted of bovine nasal septum cartilage maintained in organ culture, and the stimulus was provided by recombinant human interleukin 1 alpha. L-3-Carboxy-2,3-trans-epoxypropionyl-leucylamido-(4-guanidin o)butane (E64) and L-3-carboxy-2,3-trans-epoxypropionyl-leucylamido-(3-methyl)b utane (Ep475) showed no inhibition at concentrations up to 100 microM. In contrast, trans-epoxysuccinyl-leucylamido-(3-methyl)butane ethyl ester (Ep453), a 'prodrug' of Ep475, was an effective inhibitor. The LL-, LD- and DL-isomers gave significant inhibition at 10 microM, and the DD-isomer was inhibitory at 100 microM. None of the isomers had any detectable effect on protein synthesis or glycolysis, and their inhibitory effects were reversible. Iodoacetate inhibited proteoglycan release by a general toxic effect. Our results suggest that cysteine endopeptidase(s) play a part in cytokine-stimulated cartilage breakdown, but that effective inhibitors must pass through membranes.

Animals↗
PubMed1996

Role of cysteine endopeptidases in cancerogenesis.

Role of cysteine endopeptidases in cancerogenesis steps: neoplastic transformation, invasion and metastasis is reviewed and discussed. Positive correlation between tumor invasiveness, as well as its metastatic potential and secretion of cysteine endopeptidase (particularly cathepsins B and L) has been documented well in literature. Based on our recent results we postulate that serum endopeptidase-like activity could be used as a marker of cancer aggressiveness in diagnostic procedures in oncology. We also propose that the cysteine endopeptidase inhibitor levels (total, active and latent) could be useful factors for recognising the activation of the organism self-defence mechanisms against cancer. In addition, our idea of use of urinary cysteine peptidase inhibitors (UCPI) as potential anticancer agents is presented and discussed.

Cell Transformation, Neoplastic↗
PubMed1999

Molecular cloning and characterization of Vigna mungo processing enzyme 1 (VmPE-1), an asparaginyl endopeptidase possibly involved in post-translational processing of a vacuolar cysteine endopeptidase (SH-EP).

Asparaginyl endopeptidase is a cysteine endopeptidase that has strict substrate specificity toward the carboxy side of asparagine residues. Vigna mungo processing enzyme 1, termed VmPE-1, occurs in the cotyledons of germinated seeds of V. mungo, and is possibly involved in the post-translational processing of a vacuolar cysteine endopeptidase, designated SH-EP, which degrades seed storage protein. VmPE-1 also showed a substrate specificity to asparagine residues, and its enzymatic activity was inhibited by NEM but not E-64. In addition, purified VmPE-1 had a potential to process the recombinant SH-EP precursor to its intermediate in vitro. cDNA clones for VmPE-1 and its homologue, named VmPE-1A, were identified and sequenced, and their expressions in the cotyledons of V. mungo seedlings and other organs were investigated. VmPE-1 mRNA and SH-EP mRNA were expressed in germinated seeds at the same stage of germination although the enzymatic activity of VmPE-1 rose prior to that of SH-EP. The level of VmPE-1A mRNA continued increasing as germination proceeded. In roots, stems and leaves of fully grown plants, and in hypocotyls, VmPE-1 and VmPE-1A were little expressed. We discuss possible functions of VmPE-1 and VmPE-1A in the cotyledons of germinated seeds.

Amino Acid Sequence↗
PubMed1991

Purification of a cysteine endopeptidase which is secreted with bioactive peptides from the epidermal glands of Xenopus laevis.

The purification is reported of an endopeptidase, XSCEP1 (Xenopus skin cysteine endopeptidase), present in skin secretions of Xenopus. The procedure involved an initial concentration of the enzyme by batchwise anion-exchange chromatography and ammonium sulphate precipitation. The proteolytic activity, determined with Z-Phe-Arg-Amc (Z, benzyloxycarbonyl; Amc, 7-amidomethylcoumarin) as substrate, was fractionated by gradient ion-exchange chromatography, yielding a major component which was purified to homogeneity by chromatography on an organomercury-agarose column. SDS/PAGE demonstrated the presence of a single protein with a molecular mass of 27 kDa. The purified enzyme, which possessed a pH optimum of 5.5, exhibited the properties of a cysteine endopeptidase; it was activated by dithiothreitol and EDTA and inhibited by the mechanism-based inhibitor trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane. XSCEP1 exhibited a marked preference for substrates with a hydrophobic residue in the P1 position and arginine in the P2 position as opposed to a substrate with arginine residues in both positions. The enzyme was also able to cleave a Val-Arg-Gly sequence in a model substrate, reflecting cleavages undergone by a number of peptides present in Xenopus skin. The results point to a functional role for XSCEP1 as a putative processing enzyme.

Amino Acid Sequence↗
PubMed1995

Purification of a processing enzyme (VmPE-1) that is involved in post-translational processing of a plant cysteine endopeptidase (SH-EP).

A cysteine endopeptidase, designated SH-EP, occurs in the cotyledons of germinated seeds of Vigna mungo and acts to degrade the seed storage protein in protein storage vacuoles. SH-EP is synthesized on membrane-bound ribosomes as an inactive 45-kDa precursor, which is cotranslationally processed to a 43-kDa intermediate through cleavage of the signal sequence; the 43-kDa intermediate of SH-EP is further processed to the 33-kDa mature enzyme via 39-kDa and 36-kDa intermediates [Mitsuhashi, W. & Minamikawa, T. (1989) Plant Physiol. 89, 274-279]. The present in vitro processing experiments indicated that at least two processing enzymes, designated VmPE-1 and VmPE-2 (V. mungo processing enzymes 1 and 2), were involved in post-translational processing of SH-EP in cotyledons of V. mungo seedlings. VmPE-1 was purified from the cotyledons as a protease that was involved in the processing of the 43-kDa intermediate to the 36-kDa intermediate. The enzyme has a molecular mass of 33 kDa as estimated by SDS/polyacrylamide gel electrophoresis, and showed high similarity to the jackbean asparaginyl endopeptidase in terms of the primary structure and substrate specificity. We discuss the function of VmPE-1 in the processing of SH-EP and related proteases in the cotyledons of germinated seeds.

Albumins↗
PubMed1992

Lysosomal cysteine endopeptidases mediate interleukin 1-stimulated cartilage proteoglycan degradation.

The peptidyl diazomethane inactivator of cysteine endopeptidases, benzyloxycarbonyl-Tyr-Ala-CHN2, was tested as an inhibitor of interleukin 1 alpha-stimulated release of proteoglycan from bovine nasal septum cartilage explants. Like the previously tested epoxidyl peptide proinhibitor trans-epoxysuccinyl-leucylamido-(3-methyl)butane ethyl ester, it proved to be an effective inhibitor of proteoglycan release from cartilage, with significant inhibition at a concentration of 1 microM. The inhibition did not seem to be due to a general toxic effect. The rates of inactivation of the bovine cysteine endopeptidases by the peptidyl diazomethane, the epoxidyl peptide proinhibitor and its active form were determined. Benzyloxycarbonyl-Tyr-Ala-CHN2 proved to be a rapid inactivator of cathepsins L, S and B, but reacted much more slowly with cathepsin H and calpain. Thus it would appear that the latter two enzymes are not implicated in proteoglycan release in our test system. The peptidyl diazomethane and epoxidyl peptide proinhibitor (above) were also tested for their effects on three other interleukin 1-mediated cellular events, namely epidermal growth factor receptor transmodulation, and interleukin 6 and prostaglandin E2 production. In all cases the inactivators did not interfere with the response to interleukin 1 in human gingival fibroblasts. We conclude that one or more of the lysosomal cysteine endopeptidases cathepsins B, L and S mediate interleukin 1-stimulated cartilage proteoglycan degradation without affecting signal transduction.

Animals↗
PubMed1998

A cysteine endopeptidase with a C-terminal KDEL motif isolated from castor bean endosperm is a marker enzyme for the ricinosome, a putative lytic compartment.

A papain-type cysteine endopeptidase with a molecular mass of 35 kDa for the mature enzyme, was purified from germinating castor bean (Ricinus communis L.) endosperm by virtue of its capacity to process the glyoxysomal malate dehydrogenase precursor protein to the mature subunit in vitro (C. Gietl et al., 1997, Plant Physiol 113: 863-871). The cDNA clones from endosperm of germinating seedlings and from developing seeds were isolated and sequence analysis revealed that a very similar or identical peptidase is synthesised in both tissues. Sequencing established a presequence for co-translational targeting into the endoplasmic reticulum, an N-terminal propeptide and a C-terminal KDEL motif for the castor bean cysteine endopeptidase precursor. The 45-kDa pro-enzyme stably present in isolated organelles was enzymatically active. Immunocytochemistry with antibodies raised against the purified cysteine endopeptidase revealed highly specific labelling of ricinosomes, organelles which co-purify with glyoxysomes from germinating Ricinus endosperm. The cysteine endopeptidase from castor bean endosperm, which represents a senescing tissue, is homologous to cysteine endopeptidases from other senescing tissues such as the cotyledons of germinating mung bean (Vigna mungo) and vetch (Vicia sativa), the seed pods of maturing French bean (Phaseolus vulgaris) and the flowers of daylily (Hemerocallis sp.).

Base Sequence↗
PubMed1999

The structure and organization of two cysteine endopeptidase genes from rice.

REP-1 is a major cysteine endopeptidase that digests seed storage glutelin of rice. A cDNA clone (pRP60) for REP-1 and a cDNA clone (pRP80) for a related enzyme were previously isolated. The expression of both mRNAs is regulated by gibberellin. In this study, we revealed the structure and organization of Rep1 and RepA, genes corresponding to pRP60 and pRP80 mRNAs, respectively. Rep1 has no introns whereas RepA consists of five exons and four introns, and both genes exist as one copy gene in the rice genome. The gibberellin-responsive elements conserved in cereal alpha-amylase genes are not included in the 5'-upstream region of Rep1 or RepA. A molecular phylogenetic tree of plant cysteine endopeptidases was constructed, and their relationship was discussed.

Amino Acid Sequence↗
PubMed1994

Posttranslational processing of a carboxy-terminal propeptide containing a KDEL sequence of plant vacuolar cysteine endopeptidase (SH-EP)

A plant cysteine endopeptidase, designated SH-EP, is a major protease occurring in cotyledons of Vigna mungo seedlings, and acts to degrade seed globulin stored in protein bodies. Here we show that the 43 kDa intermediate of SH-EP formed in the endoplasmic reticulum is transported to protein bodies and processed to the 33 kDa mature form during transport or thereafter, and that the COOH-terminal propeptide of 10 amino acid residues containing a KDEL sequence, which is known as a retention signal for the endoplasmic reticulum lumen, is processed to form the mature SH-EP.

Amino Acid Sequence↗
PubMed1997

Hormonal regulation of expression of two cysteine endopeptidase genes in rice seedlings.

Two cDNA probes (pRP60 and pRP80) were used to examine the hormonal regulation of expression of two cysteine endopeptidase genes in germinated whole seeds and de-embryonated seeds of rice. The pRP60 protein is a major rice cysteine endopeptidase named REP-1 that digests rice glutelin, the main seed storage protein. The pRP80 protein has features of a cysteine endopeptidase but has not yet been confirmed to be one. Neither mRNA was detectable in dry seeds, and the levels per seed increased sharply upon imbibition, reached peaks at d 6 to d 9, and then decreased. Both mRNAs were expressed in a seed-specific manner, but the accumulation of pRP60 mRNA was about ten times greater than the other. When seeds were de-embryonated and incubated, the amounts of both mRNAs were reduced to very low levels, but in the presence of 0.01 to 1 microM gibberellic acid (GA3) both again reached high levels. Addition of abscisic acid (ABA) or uniconazole, an inhibitor of gibberellin biosynthesis, partly eliminated the effect of GA3. Protein immunoblot analysis showed that the accumulation of the REP-1 protein in seeds was regulated by GA3 and ABA similarly to that of pRP60 mRNA, but the change in pRP60 mRNA with time after the onset of imbibition preceded that of the REP-1 protein.

Abscisic Acid↗
PubMed2003

A Boophilus microplus vitellin-degrading cysteine endopeptidase.

Here we describe the purification and characterization of a vitellin (VT) degrading cysteine endopeptidase (VTDCE) from eggs of the hard tick Boophilus microplus. A homogeneous enzyme preparation was obtained by chromatographic fractionation on ion-exchange and gel filtration columns and an autolysis step. This step consisted of incubation of a semipurified enzyme (after the first ion-exchange chromatography) at pH 4.0 that dissociated the enzyme from VT, to which VTDCE is naturally tightly associated. The enzyme purity was confirmed by capillary and native gel electrophoresis, and SDS-PAGE suggested the enzyme is a dimer of 17 and 22 kDa. VTDCE was active upon several synthetic substrates, with a preference for a hydrophobic or a basic residue in P1, and a hydrophobic residue in P2. VTDCE also hydrolysed haemoglobin, albumin, gelatin and vitellin. VTDCE is inactive in the absence of DTT and was totally inhibited by E-64, indicating it is a cysteine endopeptidase. Our results suggest that VTDCE is a major enzyme involved in yolk processing during B. microplus embryogenesis.

Animals↗
PubMed1992

Cysteine endopeptidases and their inhibitors in malignant progression of rat embryo fibroblasts.

Cathepsins B and L and their endogenous inhibitors were evaluated in rat embryo fibroblast lines which have been developed as a model system for the study of malignant progression and metastatic capability. Three groups of lines were analyzed: 1) immortalized/non-tumorigenic, 2) tumorigenic/metastatic lines transfected with c-Ha-ras, and 3) metastatic revertants transfected with c-Ha-ras+the E1A region of adenovirus type 2. The metastatic revertants are tumorigenic, but non-metastatic. No correlation was seen between tumorigenicity and metastatic potential and the level of expression of cathepsin B or the subcellular distribution of cathepsins B and L. However, cathepsin L activity was increased 2-fold in the 4R metastatic line. Although transfection of aneuploid 3T3 fibroblasts with ras has been shown to increase the expression of cathepsin L and cathepsin B, transfection of the diploid rat embryo fibroblasts with ras did not correlate with increased expression of cathepsin L or cathepsin B. However, ras transfection of the rat embryo fibroblasts was associated with a significant (4-15-fold) decrease in the activity of heat-stable cysteine endopeptidase inhibitors. Thus, in tumorigenic rat embryo fibroblast lines, regulation of the activities of cysteine endopeptidases by their endogenous inhibitors may be compromised, resulting in increased effective activities of the cysteine endopeptidases.

Adenoviridae↗
PubMed2001

Comparison of two cysteine endopeptidases from Pseudananas macrodontes (Morr.) Harms (Bromeliaceae).

The properties of two cysteine peptidases (macrodontain I and II) isolated from fruits of Pseudananas macrodontes have been compared. The enzymes showed optimum pH ranges near neutrality and were inhibited by E-64 and other cysteine peptidase inhibitors. Molecular masses were 23459 and 23703 kDa, the isoelectric points were 6.1 and 5.9, and the Km values were 13.4 and 8.9 microM (Bz-Phe-Val-Arg-AMC) for macrodontain I and II, respectively. N-alpha-CBZ-L-amino acid p-nitrophenyl esters were tested for both enzymes. The N-terminal sequences of both proteases differed slightly and showed high sequence similarity to other pineapple stem-derived cysteine endopeptidases.

Amino Acid Sequence↗
PubMed1997

A cysteine endopeptidase isolated from castor bean endosperm microbodies processes the glyoxysomal malate dehydrogenase precursor protein.

A plant cysteine endopeptidase with a molecular mass of 35 kD was purified from microbodies of germinating castor bean (Ricinus communis) endosperm by virtue of its capacity to specifically process the glyoxysomal malate dehydrogenase precursor protein to the mature subunit in vitro. Processing of the glyoxysomal malate dehydrogenase precursor occurs sequentially in three steps, the first intermediate resulting from cleavage after arginine-13 within the presequence and the second from cleavage after arginine-33. The endopeptidase is unable to remove the presequences of prethiolases from rape (Brassica napus) glyoxysomes and rat peroxisomes at the expected cleavage site. Protein sequence analysis of N-terminal and internal peptides revealed high identity to the mature papain-type cysteine endopeptidases from cotyledons of germinating mung bean (Vigna mungo) and French bean (Phaseolus vulgaris) seeds. These endopeptidases are synthesized with an extended pre-/prosequence at the N terminus and have been considered to be processed in the endoplasmic reticulum and targeted to protein-storing vacuoles.

Amino Acid Sequence↗
PubMed1991

Leucoplast Pyruvate Kinase from Developing Castor Oil Seeds : Characterization of the Enzyme's Degradation by a Cysteine Endopeptidase.

Leucoplast pyruvate kinase (PK(p); EC 2.7.1.40) from endosperm of developing castor oil seeds (Ricinus communis L. cv Baker 296) appears to be highly susceptible to limited degradation by a cysteine endopeptidase during the purification of the enzyme or incubation of clarified homogenates at 4 degrees C. Purified castor seed PK(p) was previously reported to consist of immunologically related 57.5 and 44 kilodalton subunits (Plaxton WC, Dennis DT, Knowles VL [1990] Plant Physiol 94: 1528-1534). By contrast, immunoreactive polypeptides of about 63.5 and 54 kilodaltons were observed when a western blot of an extract prepared under denaturing conditions was probed with affinity purified rabbit anti-(castor seed PK(p)) immunoglobulin G. Proteolytic activity against PK(p) was estimated by the disappearance of the 63.5 and 54 kilodalton subunits and the concomitant appearance of lower molecular mass immunoreactive degradation products during the incubation of clarified homogenates at 4 degrees C. The presence of 2 millimolar dithiothreitol accelerated the degradation of PK(p). The conservation of the 63.5 and 54 kilodalton subunits was observed after extraction of the enzyme in the presence of 1 millimolar p-hydroxymecuribenzoate, or 1 millimolar Nalpha-p-tosyl-l-lysine chloromethyl ketone, or 10 millimolar iodoacetate. These results reveal that a cysteine endopeptidase was responsible for the in vitro proteolysis of PK(p). This endopeptidase is present throughout all stages of endosperm development. Its PK(p)-degrading activity, however, appears to be most pronounced in preparations from older endosperm. When lysates of purified leucoplasts were incubated at 4 degrees C for up to 21 hours, no degradation of PK(p) was observed; this indicated an extra-leucoplastic localization for the cysteine endopeptidase. Although the in vivo subunit structure of PK(p) remains uniform throughout all stages of endosperm development, the large decrease in PK activity that accompanies castor seed maturation coincides with a marked reduction in the concentration of PK(p).

Journal Article↗