scholarly journals Dual concentration-dependent activity of thyroglobulin type-1 domain of testican: specific inhibitor and substrate of cathepsin L

2005 ◽  
Vol 386 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Primož Meh ◽  
Miha Pavšič ◽  
Vito Turk ◽  
Antonio Baici ◽  
Brigita Lenarčič
Keyword(s):  
Homology Modelling ◽  
Cathepsin L ◽  
Expression System ◽  
Specific Inhibitor ◽  
Cathepsin K ◽  
Selective Inhibition ◽  
Cysteine Residue ◽  
Catalytic Cysteine

Abstract The thyroglobulin type-1 (Tg-1) domain is a protein module that occurs in a variety of secreted and membrane proteins and is recognised as a potent inhibitor of cysteine peptidases. We present here some properties of the Tg-1 domain of human testican, a modularly organised proteoglycan secreted mainly by brain cells, the exact in vivo function of which is not yet clear. The domain was prepared as a recombinant protein in a Pichia pastoris expression system and its activity was demonstrated by specific and selective inhibition of cathepsin L (K i=0.14 nM). Interaction at high enzyme and inhibitor concentrations resulted in degradation of the domain by cathepsin L, which was not observed under conditions used for the determination of kinetic parameters. No inhibitory activity could be detected for cathepsin K, but it exhibited a very similar degradation pattern. Homology modelling provided a good explanation for the different behaviour observed with the two enzymes. Firstly, the steric fit between the interfaces of testican domain and cathepsin L is stabilised by numerous favourable forces, while no such interactions are evident in the complex with cathepsin K, and repulsive interactions even prevent access of the domain to the active site of papain. Secondly, the prolonged first loop of the domain occupies a position near the catalytic cysteine residue in a more substrate-like manner, enabling cleavage of the Gly22-Ala23 bond.

Localization of Rat Cathepsin K in Osteoclasts and Resorption Pits: Inhibition of Bone Resorption and Cathepsin K-Activity by Peptidyl Vinyl Sulfones

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
L. Xia ◽  
J. Kilb ◽  
H. Wex ◽  
Z. Li ◽  
A. Lipyansky ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Cathepsin L ◽  
Critical Role ◽  
Specific Inhibitor ◽  
Cathepsin K ◽  
Selective Inhibition ◽  
Specific Substrate ◽  
Dependent Manner ◽  
Protease Inhibition ◽  
K Activity

AbstractWe have localized cathepsin K in rat osteoclasts and within exposed resorption pits by immuno-fluorescence microscopy. Intracellular staining using an antibody raised against recombinant mouse cathepsin K was vesicular and uniformly distributed throughout the cell. Confocal microscopy analysis did not reveal an accumulation of cathepsin K containing vesicles opposing the ruffled border and the resorption lacuna. Exposed resorption pits exhibited a uniform distribution of cathepsin K, and no differences were observed between the edges and the centers of the pits. The immunostaining of resorption pits with anti-cathepsin K antibodies demonstrates that the protease is secreted into the sub-osteoclastic compartment.Cathepsin K-specific inhibition using peptidyl vinyl sulfones as selective cysteine protease inactivators reduced bone resorption by 80% in a dose-dependent manner at sub-micromolar concentrations. No reduction of bone resorption was observed at those low concentrations using a potent cathepsin L, S, B-specific inhibitor. That the inhibition of bone resorption can be attributed to cathepsin K-like protease inhibition was corroborated by the selective inhibition of the osteoclastic Z-Gly-Pro-Arg-MβNA hydrolyzing activity by the cathepsin K, L, S, B-inhibitor, but not by the cathepsin L, B, and S inhibitor. Z-Gly-Pro-Arg-MβNA is efficiently hydrolyzed by cathepsin K but only poorly by cathepsins L, S, and B. On the contrary, the intracellular hydrolysis of the cathepsin B-specific substrate, Z-Arg-Arg-MβNA, was prevented by both types of inhibitors.The identification of cathepsin K in resorption pits and the inhibition of bone resorption and intracellular cathepsin K activity by selective vinyl sulfone inhibitors indicate the critical role of the protease in osteoclastic bone resorption.

A possible alternative mechanism of kinin generation in vivo by cathepsin L

2005 ◽  
Vol 386 (7) ◽  
pp. 699-704 ◽  
Author(s):  
Luciano Puzer ◽  
Juliana Vercesi ◽  
Marcio F.M. Alves ◽  
Nilana M.T. Barros ◽  
Mariana S. Araujo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Enzyme Inhibitor ◽  
Alternative Pathway ◽  
Cathepsin L ◽  
Specific Inhibitor ◽  
Cysteine Proteases ◽  
Hypotensive Effect ◽  
Alternative Mechanism

Abstract We investigated the ability of cathepsin L to induce a hypotensive effect after intravenous injection in rats and correlated this decrease in blood pressure with kinin generation. Simultaneously with blood pressure decrease, we detected plasma kininogen depletion in the treated rats. The effect observed in vivo was abolished by pre-incubation of cathepsin L with the cysteine peptidase-specific inhibitor E-64 (1 μM) or by previous administration of the bradykinin B2 receptor antagonist JE049 (4 mg/kg). A potentiation of the hypotensive effect caused by cathepsin L was observed by previous administration of the angiotensin I-converting enzyme inhibitor captopril (5 mg/kg). In vitro studies indicated that cathepsin L excised bradykinin from the synthetic fluorogenic peptide Abz-MTSVIRRPPGFSPFRAPRV-NH2, based on the Met375–Val393 sequence of rat kininogen (Abz=o-aminobenzoic acid). In conclusion, our data indicate that in vivo cathepsin L releases a kinin-related peptide, and in vitro experiments suggest that the kinin generated is bradykinin. Although it is well known that cysteine proteases are strongly inhibited by kininogen, cathepsin L could represent an alternative pathway for kinin production in pathological processes.

scholarly journals IMP dehydrogenase from Pneumocystis carinii as a potential drug target.

1997 ◽  
Vol 41 (1) ◽  
pp. 40-48 ◽  
Author(s):  
M J O'Gara ◽  
C H Lee ◽  
G A Weinberg ◽  
J M Nott ◽  
S F Queener
Keyword(s):  
Mycophenolic Acid ◽  
Expression System ◽  
Pneumocystis Carinii ◽  
Specific Inhibitor ◽  
Coli Strain ◽  
Northern Hybridization ◽  
Imp Dehydrogenase ◽  
E Coli ◽  
The Mean

Mycophenolic acid, a specific inhibitor of IMP dehydrogenase (IMPDH; EC 1.1.1.205), is a potent inhibitor of Pneumocystis carinii growth in culture, suggesting that IMPDH may be a sensitive target for chemotherapy in this organism. The IMPDH gene was cloned as a first step to characterizing the enzyme and developing selective inhibitors. A 1.3-kb fragment containing a portion of the P. carinii IMPDH gene was amplified by PCR with two degenerate oligonucleotides based on conserved sequences in IMPDH from humans and four different microorganisms. Northern hybridization analysis showed the P. carinii IMPDH mRNA to be approximately 1.6 kb. The entire cDNA encoding P. carinii IMPDH was isolated and cloned. The deduced amino acid sequence of P. carinii IMPDH shared homology with bacterial (31 to 38%), protozoal (48 to 59%), mammalian (60 to 62%), and fungal (62%) IMPDH enzymes. The IMPDH cDNA was expressed by using a T7 expression system in an IMPDH-deficient strain of Escherichia coli (strain S phi 1101). E. coli S phi 1101 cells containing the P. carinii IMPDH gene were able to grow on medium lacking guanine, implying that the protein expressed in vivo was functional. Extracts of these E. coli cells contained IMPDH activity that had an apparent Km for IMP of 21.7 +/- 0.3 microM and an apparent Km for NAD of 314 +/- 84 microM (mean +/- standard error of the mean; n = 3), and the activity was inhibited by mycophenolic acid (50% inhibitory concentration, 24 microM; n = 2).

scholarly journals Development of a New Antileishmanial Aziridine-2,3-Dicarboxylate-Based Inhibitor with High Selectivity for Parasite Cysteine Proteases

2015 ◽  
Vol 60 (2) ◽  
pp. 797-805 ◽  
Author(s):  
Caroline Schad ◽  
Ulrike Baum ◽  
Benjamin Frank ◽  
Uwe Dietzel ◽  
Felix Mattern ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Neglected Tropical Diseases ◽  
Cathepsin L ◽  
Selective Inhibition ◽  
Cysteine Proteases ◽  
Host Cells ◽  
Th2 Response ◽  
Content Type

ABSTRACTLeishmaniasis is one of the major neglected tropical diseases of the world. Druggable targets are the parasite cysteine proteases (CPs) of clan CA, family C1 (CAC1). In previous studies, we identified two peptidomimetic compounds, the aziridine-2,3-dicarboxylate compounds 13b and 13e, in a series of inhibitors of the cathepsin L (CL) subfamily of the papain clan CAC1. Both displayed antileishmanial activityin vitrowhile not showing cytotoxicity against host cells. In further investigations, the mode of action was characterized inLeishmania major. It was demonstrated that aziridines 13b and 13e mainly inhibited the parasitic cathepsin B (CB)-like CPC enzyme and, additionally, mammalian CL. Although these compounds induced cell death ofLeishmaniapromastigotes and amastigotesin vitro, the induction of a proleishmanial T helper type 2 (Th2) response caused by host CL inhibition was observedin vivo. Therefore, we describe here the synthesis of a new library of more selective peptidomimetic aziridine-2,3-dicarboxylates discriminating between host and parasite CPs. The new compounds are based on 13b and 13e as lead structures. One of the most promising compounds of this series is compound s9, showing selective inhibition of the parasite CPsLmaCatB (a CB-like enzyme ofL. major; also namedL. majorCPC) andLmCPB2.8 (a CL-like enzyme ofLeishmania mexicana) while not affecting mammalian CL and CB. It displayed excellent leishmanicidal activities againstL. majorpromastigotes (50% inhibitory concentration [IC50] = 37.4 μM) and amastigotes (IC50= 2.3 μM). In summary, we demonstrate a new selective aziridine-2,3-dicarboxylate, compound s9, which might be a good candidate for futurein vivostudies.

scholarly journals Expression and alteration of the S2 subsite of the Leishmania major cathepsin B-like cysteine protease

1999 ◽  
Vol 340 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Victor J. CHAN ◽  
Paul M. SELZER ◽  
James H. McKERROW ◽  
Judy A. SAKANARI
Keyword(s):  
Cathepsin B ◽  
Leishmania Major ◽  
Cathepsin L ◽  
Expression System ◽  
Specific Inhibitor ◽  
Structural Similarity ◽  
Cysteine Proteases ◽  
Recombinant Enzyme ◽  
Yeast Expression System ◽  
S2 Subsite

The mature form of the cathepsin B-like protease of Leishmania major (LmajcatB) is a 243 amino acid protein belonging to the papain family of cysteine proteases and is 54% identical to human-liver cathepsin B. Despite the high identity and structural similarity with cathepsin B, LmajcatB does not readily hydrolyse benzyloxycarbonyl-Arg-Arg-7-amino-4-methyl coumarin (Z-Arg-Arg-AMC), which is cleaved by cathepsin B enzymes. It does, however, hydrolyse Z-Phe-Arg-AMC, a substrate typically cleaved by cathepsin L and B enzymes. Based upon computer generated protein models of LmajcatB and mammalian cathepsin B, it was predicted that this variation in substrate specificity was attributed to Gly234 at the S2 subsite of LmajcatB, which forms a larger, more hydrophobic pocket compared with mammalian cathepsin B. To test this hypothesis, recombinant LmajcatB was expressed in the Pichia pastoris yeast expression system. The quality of the recombinant enzyme was confirmed by kinetic characterization, N-terminal sequencing, and Western blot analysis. Alteration of Gly234 to Glu, which is found at the corresponding site in mammalian cathepsin B, increased recombinant LmajcatB (rLmajcatB) activity toward Z-Arg-Arg-AMC 8-fold over the wild-type recombinant enzyme (kcat/Km = 3740±413 M-1·s-1 versus 472±72.4 M-1·s-1). The results of inhibition assays of rLmajcatB with an inhibitor of cathepsin L enzymes, K11002 (morpholine urea-Phe-homoPhe-vinylsulphonylphenyl, kinact/Ki = 208200±36000 M-1·s-1), and a cathepsin B specific inhibitor, CA074 [N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-ʟ-isoleucyl-L-proline, kinact/Ki = 199200±32900 M-1·s-1], support the findings that this protozoan protease has the P2 specificity of cathepsin L-like enzymes while retaining structural homology to mammalian cathepsin B.

scholarly journals The rhodanese RhdA helps Azotobacter vinelandii in maintaining cellular redox balance

2010 ◽  
Vol 391 (7) ◽  
Author(s):  
William Remelli ◽  
Angelo Cereda ◽  
Jutta Papenbrock ◽  
Fabio Forlani ◽  
Silvia Pagani
Keyword(s):  
Oxidative Stress ◽  
Stress Condition ◽  
Azotobacter Vinelandii ◽  
Redox Balance ◽  
Cysteine Residue ◽  
Structural Peculiarity ◽  
Cellular Redox ◽  
Catalytic Cysteine ◽  
Transcript Profiles

AbstractThe tandem domain rhodanese-homology protein RhdA ofAzotobacter vinelandiishows an active-site loop structure that confers structural peculiarity in the environment of its catalytic cysteine residue. Thein vivoeffects of the lack of RhdA were investigated using anA. vinelandiimutant strain (MV474) in which therhdAgene was disrupted by deletion. Here, by combining analytical measurements and transcript profiles, we show that deletion of therhdAgene generates an oxidative stress condition to whichA. vinelandiiresponds by activating defensive mechanisms. In conditions of growth in the presence of the superoxide generator phenazine methosulfate, a stressor-dependent induction ofrhdAgene expression was observed, thus highlighting that RhdA is important forA. vinelandiito sustain oxidative stress. The potential of RhdA to buffer general levels of oxidants inA. vinelandiicells via redox reactions involving its cysteine thiol is discussed.

The role and regulation of 11β-hydroxysteroid dehydrogenase type 1 in obesity and the metabolic syndrome

2013 ◽  
Vol 15 (2) ◽  
Author(s):  
Roland H. Stimson ◽  
Brian R. Walker
Keyword(s):  
Metabolic Disease ◽  
Adipose Tissue ◽  
Selective Inhibition ◽  
Hydroxysteroid Dehydrogenase ◽  
The Metabolic Syndrome ◽  
Specific Regulation ◽  
Visceral Adipose ◽  
Subcutaneous Adipose

AbstractThe cortisol regenerating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) amplifies tissue glucocorticoid levels, particularly in the liver and adipose tissue. The importance of this enzyme in causing metabolic disease was highlighted by transgenic mice which over- or under-expressed 11β-HSD1; consequently, selective 11β-HSD1 inhibitors have been widely developed as novel agents to treat obesity and type 2 diabetes mellitus (T2DM). This review focuses on the importance of 11β-HSD1 in humans which has been more difficult to ascertain. The recent development of a deuterated cortisol tracer has allowed us to quantify in vivo cortisol production by 11β-HSD1. These results have been surprising, as cortisol production rates by 11β-HSD1 are at least equivalent to that of the adrenal glands. The vast majority of this production is by the liver (>90%) with a smaller contribution from subcutaneous adipose tissue and possibly skeletal muscle, but with no detectable production from visceral adipose tissue. This tracer has also allowed us to quantify the tissue-specific regulation of 11β-HSD1 observed in obesity and obesity-associated T2DM, determine the likely basis for this dysregulation, and identify obese patients with T2DM as the group most likely to benefit from selective inhibition of 11β-HSD1. Some of these inhibitors have now reached Phase II clinical development, demonstrating efficacy in the treatment of T2DM. We review these results and discuss whether selective 11β-HSD1 inhibitors are likely to be an important new therapy for metabolic disease.

scholarly journals Mutation of chicken anemia virus VP2 differentially affects serine/threonine and tyrosine protein phosphatase activities

2005 ◽  
Vol 86 (3) ◽  
pp. 623-630 ◽  
Author(s):  
Michelle A. Peters ◽  
David C. Jackson ◽  
Brendan S. Crabb ◽  
Glenn F. Browning
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatase ◽  
Cysteine Residue ◽  
Chicken Anemia Virus ◽  
Tt Virus ◽  
Inhibition Of Growth ◽  
Catalytic Cysteine ◽  
Anemia Virus

Novel dual-specificity protein phosphatases (DSPs), which catalyse the removal of phosphate from both phosphotyrosine and phosphoserine/phosphothreonine substrates, have recently been identified in two viruses within the family Circoviridae. Viral protein 2 (VP2) of chicken anemia virus (CAV) and ORF2 of TT virus have been shown to possess DSP activity in vitro. CAV VP2 is unusual in possessing two vicinal cysteines within the protein phosphatase signature motif. The first cysteine residue (C95) within the motif has been identified by mutagenesis as the essential catalytic cysteine. In this study, it was shown that virus mutated at this residue displayed a marked inhibition of growth, with titres reduced 104-fold, and reduced cytopathogenic effect in cell culture, indicating that viral DSP activity may be significant during infection. As with virus mutated at the first cysteine residue, mutation of the second cysteine (C97) within the motif resulted in a marked reduction in viral growth and attenuation of cytopathogenicity in infected cell cultures. However, mutagenesis of this second cysteine only reduced phosphotyrosine phosphatase activity to 70 % of that of wild-type VP2, but increased phosphoserine/phosphothreonine phosphatase activity by as much as 700 %. The differential effect of the C97S mutation on VP2 activity does not appear to have parallels in other DSPs and suggests a unique role for the second cysteine in the function of these viral proteins, particularly in vivo.

scholarly journals Selective pharmaceutical inhibition of PARP14 mitigates allergen-induced IgE and mucus overproduction in a mouse model of pulmonary allergic response

2021 ◽  
Author(s):  
Alex M. Eddie ◽  
Laurie B. Schenkel ◽  
Kerren K. Swinger ◽  
Jennifer R. Molina ◽  
Kaiko Kunii ◽  
...  
Keyword(s):  
Specific Inhibitor ◽  
Selective Inhibition ◽  
Health Issues ◽  
Adp Ribosylation ◽  
Catalytic Function ◽  
Biological Responses ◽  
Allergic Lung Inflammation ◽  
Type 2 Cytokines ◽  
Adp Ribosyltransferase

The type 2 cytokines IL-4 and IL-13, which share use of an IL-4 receptor alpha chain and its nuclear induction of the transcription factor STAT6, are crucial in elicitation and maintenance of allergic conditions that include asthma. Prior work has shown a physical and functional association of STAT6 with PARP14, an ADP-ribosyl monotransferase. Moreover, elimination of all PARP14 expression by gene targeting led to altered recall antibody responses and attenuation of ovalbumin-specific allergic lung inflammation with no apparent health issues for mice lacking this protein. However, an unanswered question is whether or not inhibition of the catalytic function has any biological consequence since PARP14 has multiple functional domains apart from the portion that catalyzes ADP-ribosylation. As reported separately, iterative structural analyses and medicinal chemistry fostered the generation of a compound, RBN2759, that is highly selective in its inhibition of PARP14 with negligible impact on other members of the PARP gene family. We show here that administration of this compound to mice previously sensitized to the allergen Alternaria alternata achieved biochemically active levels and altered physiological responses to the antigen. These results show for the first time that in vivo administration of a specific inhibitor of the ADP-ribosyltransferase activity encoded by PARP14 is sufficient to alter biological responses. Specifically, the orally absorbable pharmaceutical compound decreased allergen-induced mucus, blunted the induced increases in circulating IgE, and prevented suppression of IgG2a. We conclude that the catalytic activity can contribute to pathogenesis in allergic processes and propose that other biological endpoints that depend on ADP-ribosylation by PARP14 can be targeted using selective inhibition.

scholarly journals 11 beta-hydroxysteroid dehydrogenase type 1 is a predominant 11 beta-reductase in the intact perfused rat liver

2000 ◽  
Vol 165 (3) ◽  
pp. 685-692 ◽  
Author(s):  
PM Jamieson ◽  
BR Walker ◽  
KE Chapman ◽  
R Andrew ◽  
S Rossiter ◽  
...  
Keyword(s):  
Rat Liver ◽  
Reductase Activity ◽  
Chronic Administration ◽  
Selective Inhibition ◽  
Hydroxysteroid Dehydrogenase ◽  
Rat Plasma ◽  
Male Rat ◽  
Perfused Rat Liver

11 beta-Hydroxysteroid dehydrogenase type 1 (11 beta-HSD-1), a regulator of intrahepatocellular glucocorticoid activity, is bidirectional in homogenates but catalyses 11 beta-reduction (regenerating glucocorticoid) in intact primary hepatocytes in culture. To examine this discrepancy at the whole-organ level, we examined 11 beta-HSD-1 activity in the intact bivascularly perfused rat liver. On a single pass through male rat liver, 44+/-5% of 11-dehydrocorticosterone (11-DHC) recovered was 11 beta-reduced to corticosterone, whereas 10+/-1% of corticosterone was 11 beta-dehydrogenated to 11-DHC. 11 beta-Reduction was less in female liver (21+/-2%, P<0.01) and was significantly greater with perfusion of all substrate via the portal vein (50+/-3%) than via the hepatic artery (30+/-2%, P<0.05). 11 beta-Reductase activity was not saturated by 11-DHC (10(-)(9)-10(-)(6) M). Perfusion with carbenoxolone (CBX, 10(-)(6)-10(-)(3 )M) did not alter 11 beta-reduction of 11-DHC. In contrast, pretreatment with CBX in vivo (10 mg/day) for 7 days inhibited 11 beta-reductase (19+/-4% conversion, P<0.01). Concentrations of 11-DHC in male rat plasma were 44+/-6 nM. Thus 11 beta-HSD-1 is predominantly an 11 beta-reductase in the intact rat liver and is only inhibited by chronic administration of CBX. The substantial concentrations of plasma 11-DHC as substrate suggest that 11 beta-HSD-1 activity and its potential selective inhibition could modify glucocorticoid action in vivo.

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