scholarly journals Human sputum cathepsin B degrades proteoglycan, is inhibited by α2-macroglobulin and is modulated by neutrophil elastase cleavage of cathepsin B precursor and cystatin C

1991 ◽  
Vol 276 (2) ◽  
pp. 325-331 ◽  
Author(s):  
D J Buttle ◽  
M Abrahamson ◽  
D Burnett ◽  
J S Mort ◽  
A J Barrett ◽  
...  
Keyword(s):  
Cystatin C ◽  
Neutrophil Elastase ◽  
Cathepsin B ◽  
Cysteine Proteinase ◽  
Fold Increase ◽  
Stable Form ◽  
Zymogen Activation ◽  
Truncated Form ◽  
Α2 Macroglobulin

The high-Mr alkali-stable form of cathepsin B was purified from purulent human sputum. It was shown to solubilize proteoglycan monomer entrapped in polyacrylamide at a rate comparable with that of human lysosomal cathepsin B. Like the enzyme from lysosomes, sputum cathepsin B was bound by human alpha 2-macroglobulin, which inhibited its action on proteoglycan. Cystatin C in purulent sputum was shown to be the N-terminally truncated form generated by neutrophil elastase cleavage, and sputum cathepsin B was only weakly inhibited by recombinant cystatin C that had been cleaved by neutrophil elastase in vitro. Addition of neutrophil elastase to mucoid sputum led to a 5-fold increase in cathepsin B activity concomitant with a lowering in Mr of the cysteine proteinase from 40,000 to 37,000, i.e. the size of the active enzyme purified from purulent sputum. It is concluded that the high-Mr form of cathepsin B present in purulent sputum is a functional proteinase, unlike similar forms of the enzyme secreted by mammary gland in organ culture. The activity of cathepsin B in sputum is modulated by neutrophil elastase, by a combination of inhibitor inactivation and zymogen activation.

scholarly journals A catalytically active high-Mr form of human cathepsin B from sputum

1988 ◽  
Vol 254 (3) ◽  
pp. 693-699 ◽  
Author(s):  
D J Buttle ◽  
B C Bonner ◽  
D Burnett ◽  
A J Barrett
Keyword(s):  
Lysosomal Enzyme ◽  
Active Site ◽  
Cathepsin B ◽  
Human Liver ◽  
Cysteine Proteinase ◽  
Truncated Form ◽  
Physiological Importance ◽  
Catalytically Active ◽  
Human Cathepsin ◽  
Chicken Cystatin

A cysteine proteinase from purulent sputum was partially purified by a method involving affinity chromatography on Sepharose-aminohexanoylphenylalanylglycinaldehyde semicarbazone. It was immunologically related to lysosomal cathepsin B from human liver and was similar in many, but not all, other aspects. It was catalytically active, as demonstrated by active-site-directed radioiodination, and hydrolysed three cathepsin B substrates, two with Km values similar to those of lysosomal cathepsin B. In addition, the rates of inactivation of the sputum and lysosomal forms of the enzyme by L-3-carboxy-2,3-transepoxypropionyl-leucylamido(4-guanidino) butane (Compound E-64) were very similar. However, the sputum enzyme differed from lysosomal cathepsin B in the following respects. Inhibition by chicken cystatin was much weaker for sputum cathepsin B than for the lysosomal enzyme. Sputum cathepsin B had greater stability at pH 7.5 and a higher apparent Mr, even after deglycosylation, than lysosomal cathepsin B. We conclude that the form of cathepsin B found in sputum is probably a truncated form of human procathepsin B, with some differences in properties that could be of physiological importance.

scholarly journals Activation of procathepsin B in human hepatoma cells: the conversion into the mature enzyme relies on the action of cathepsin B itself

1993 ◽  
Vol 293 (2) ◽  
pp. 437-442 ◽  
Author(s):  
L Mach ◽  
H Schwihla ◽  
K Stüwe ◽  
A D Rowan ◽  
J S Mort ◽  
...  
Keyword(s):  
Cathepsin B ◽  
Mammalian Cells ◽  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Human Hepatoma ◽  
Single Chain ◽  
Human Hepatoma Cells ◽  
Chain Form

In order to elucidate the processing mechanism of the lysosomal cysteine proteinase, cathepsin B, in mammalian cells, recombinant rat and human cathepsin B precursors were expressed in Saccharomyces cerevisiae. The active-site cysteine residue was changed to serine to prevent autoprocessing. When the purified proenzymes were incubated with the soluble fraction of postnuclear organelles obtained from human hepatoma HepG2 cells, processing to a 33 kDa form corresponding to the mature endogenous single-chain enzyme was observed. Inhibitors of metallo-, serine and aspartic proteinases exerted no significant effect on procathepsin B processing in vitro. However, the processing activity was effectively blocked by cysteine proteinase inhibitors, in particular E-64 and its cathepsin-B-selective derivative CA-074. Processing positions were identified by using anti-peptide antibodies specific for epitopes in the N- and C-terminal cleavage regions. The single-chain form produced in vitro was thus shown to contain an N-terminal extension of at least four residues relative to the mature lysosomal enzyme, as well as a C-terminal extension present in the proenzyme but usually absent in fully processed cathepsin B. On expression of the wild-type proenzyme in yeast, procathepsin B undergoes autoprocessing, yielding a single-chain form of the active enzyme, which contains similar N- and C-terminal extensions. These results indicate that maturation of procathepsin B in vivo in mammalian tissues relies on the proteolytic activity of cathepsin B itself.

Toward understanding recurrent meningioma: the potential role of lysosomal cysteine proteases and their inhibitors

2010 ◽  
Vol 112 (5) ◽  
pp. 940-950 ◽  
Author(s):  
Tamara T. Lah ◽  
Isabelle Nanni ◽  
Miha Trinkaus ◽  
Philipe Metellus ◽  
Christophe Dussert ◽  
...  
Keyword(s):  
Cystatin C ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Who Grade ◽  
Simpson Grade ◽  
Cysteine Cathepsins ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
Meningioma Recurrence

Object The first aim of this study was to diagnose more aggressive and potentially recurrent meningiomas using an in vitro embryonic chick heart invasiveness assay in which lysosomal enzyme cathepsin B was used as the invasiveness marker. The second aim was to confirm if cathepsin B and/or cathepsin L and their endogenous inhibitors were also prognostic parameters in the clinical study of 119 patients with meningioma. Methods Primary meningioma cultured spheroids were “confronted” with embryonic chick heart spheroids in vitro, and cathepsin B was used as molecular marker to immunolabel the invasive tumor cells. In vitro invasion assays of the malignant meningioma cells were used to assess the invasive potential related to the cysteine cathepsins. As to the second aim, the possible association of cathepsin B along with selected molecular markers, cathepsin L, and endogenous cysteine protease inhibitors (stefins A and B and cystatin C) with meningioma malignancy was determined using enzyme-linked immunosorbent assays in tumor homogenates. Univariate and multivariate analyses were used to compare these parameters with established biological markers of meningioma recurrence in 119 patients with meningiomas. Results The more invasive tumors, which characteristically overgrew the normal tissue, were identified even within a group of histologically benign meningiomas. More intensive staining of cathepsin B in these tumors was not only found at the tumor front, but also in the invading pseudopodia of a single migrating tumor cells. Matrigel invasion of malignant meningioma cells was significantly altered by modulating cathepsin B activity and by stefin B silencing. In the clinical samples of meningioma, the levels of cathepsins B and L, stefin B, and cystatin C were highest in the tumors of higher histological grades, whereas stefin A and progesterone receptor were the only markers that were significantly increased and decreased, respectively, in WHO Grade III lesions. With respect to the prognosis of relapse, cathepsin L (p = 0.035), stefin B (p = 0.007), cystatin C (p = 0.008), and progesterone receptor (p = 0.049) levels were significant, whereas cathepsin B was not a prognosticator. As expected, WHO grade, age, and Simpson grade (complete tumor resection) were prognostic, with Simpson grade only relevant in the short term (up to 90 months) but not in longer-term follow-up. Of note, the impact of all these parameters was lost in multivariate analysis, due to overwhelming prognostic impact of stefin B (p = 0.039). Conclusions The data indicate that the cysteine cathepsins and their inhibitors are involved in a process related to early meningioma recurrence, regardless of their histological classification. Of note, the known tumor invasiveness marker cathepsin B, measured in whole-tumor homogenates, was not prognostic, in contrast to its endogenous inhibitor stefin B, which was highly significant and the only independent prognostic factor to predict meningioma relapse in multivariate analysis and reported herein for the first time. Stefin B inhibition of local invasion was confirmed by in vitro invasion assay, although its other functions cannot be excluded.

Effect of Cysteine Proteinase Inhibitors on Murine B16 Melanoma Cell Invasion in vitro

2002 ◽  
Vol 383 (5) ◽  
pp. 839-842 ◽  
Author(s):  
Natasa Sever ◽  
Metka Filipic ◽  
Joze Brzin ◽  
Tamara T. Lah
Keyword(s):  
Cell Invasion ◽  
Cathepsin B ◽  
Proteinase Inhibitor ◽  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Cathepsin L ◽  
Cysteine Proteinase Inhibitor ◽  
Cysteine Proteinases ◽  
Cysteine Proteinase Inhibitors

Abstract Various types of proteinases are implicated in the malignant progression of human and animal tumors. Proteinase inhibitors may therefore be useful as therapeutic agents in antiinvasive and antimetastatic treatment. The aims of this study were (1) to estimate the relative importance of proteinases in B16 cell invasion in vitro using synthetic, classspecific proteinase inhibitors and (2) to assess the inhibitory effect of some naturally occurring cysteine proteinase inhibitors. Serine proteinase inhibitor reduced invasiveness by up to 24%, whereas inhibition of aspartic proteinases reduced invasion by 11%. Synthetic inhibitors of cysteine proteinases markedly impaired invasion: cathepsin B inhibitors, particularly Ca 074Me, inhibited invasion from 20 40%, whereas cathepsin L inhibitor Clik 148 reduced invasion by 11%. The potato cysteine proteinase inhibitor PCPI 8.7 inhibited invasion by 21%, whereas another potato inhibitor, PCPI 6.6, and the mushroom cysteine proteinase inhibitor clitocypin had no effects. As the inhibitors that inhibited cathepsin B were in general more efficient at impairing the invasiveness, we conclude that of the two cysteine proteinases, cathepsin B plays a more important role than cathepsin L in murine melanoma cell invasion.

Inhibition of the cathepsin B like proteinase by a low molecular weight cysteine-proteinase inhibitor from ascitic fluid and plasma α2 macroglobulin

1986 ◽  
Vol 64 (12) ◽  
pp. 1218-1225 ◽  
Author(s):  
Maurice Pagano ◽  
Daniel Keppler ◽  
Veronique Fumeron-Dalet ◽  
Robert Engler
Keyword(s):  
Molecular Weight ◽  
Ascitic Fluid ◽  
Cathepsin B ◽  
Proteinase Inhibitors ◽  
Cysteine Proteinase ◽  
Low Molecular Weight ◽  
Cysteine Proteinase Inhibitor ◽  
Cysteine Proteinase Inhibitors ◽  
Α2 Macroglobulin ◽  
Endopeptidase Activity

The cathepsin B like proteinase present in ascitic fluid of a patient with neoplasia has been purified and characterized after pepsin activation. From this fluid we have prepared the low molecular weight (LMW) cysteine-proteinase inhibitors. Three major inhibitor forms were found with isoelectric points of 7.4, 5.4, and 5.1, respectively. The interaction of the enzyme with the former inhibitor was studied because this inhibitor was the most abundant. The Ki value was found to be 4.3 × 10−8 M. Two molecules of this proteinase were bound by one molecule of plasma α2 macroglobulin (α2M). The LMW inhibitor was able to bind to the enzyme entrapped in α2M and reduced its endopeptidase activity on benzyloxycarbonyl-L-phenylalanyl-L-arginine-4-methyl-7-coumarylamide. These results may have a physiological significance in the regulation of the enzyme which, among other extracellular hydrolases, probably plays an important role in tumor invasion.

scholarly journals Oxidized mucus proteinase inhibitor: a fairly potent neutrophil elastase inhibitor

1994 ◽  
Vol 303 (1) ◽  
pp. 61-68 ◽  
Author(s):  
C Boudier ◽  
J G Bieth
Keyword(s):  
Rate Constant ◽  
Neutrophil Elastase ◽  
Proteinase Inhibitor ◽  
Enzyme Inhibitor ◽  
Fold Increase ◽  
Upper Respiratory Tract ◽  
Neutrophil Elastase Inhibitor ◽  
Active Centre ◽  
Elastase Inhibitor

N-chlorosuccinimide oxidizes one of the methionine residues of mucus proteinase inhibitor with a second-order rate constant of 1.5 M-1.s-1. Cyanogen bromide cleavage and NH2-terminal sequencing show that the modified residue is methionine-73, the P′1 component of the inhibitor's active centre. Oxidation of the inhibitor decreases its neutrophil elastase inhibitory capacity but does not fully abolish it. The kinetic parameters describing the elastase-oxidized inhibitor interaction are: association rate constant kass. = 2.6 x 10(5) M-1.s-1, dissociation rate constant kdiss. = 2.9 x 10(-3) s-1 and equilibrium dissociation constant Ki = 1.1 x 10(-8) M. Comparison with the native inhibitor indicates that oxidation decreases kass. by a factor of 18.8 and increases kdiss. by a factor of 6.4, and therefore leads to a 120-fold increase in Ki. Yet, the oxidized inhibitor may still act as a potent elastase inhibitor in the upper respiratory tract where its concentration is 500-fold higher than Ki, i.e. where the elastase inhibition is pseudo-irreversible. Experiments in vitro with fibrous human lung elastin, the most important natural substrate of elastase, support this view: 1.35 microM elastase is fully inhibited by 5-6 microM oxidized inhibitor whether the enzyme-inhibitor complex is formed in the presence or absence of elastin and whether elastase is pre-adsorbed on elastin or not.

scholarly journals Zymogen activation in a reconstituted pancreatic acinar cell system

2006 ◽  
Vol 290 (5) ◽  
pp. G894-G902 ◽  
Author(s):  
Edwin C. Thrower ◽  
Alexander P. E. Diaz de Villalvilla ◽  
Thomas R. Kolodecik ◽  
Fred S. Gorelick
Keyword(s):  
Acute Pancreatitis ◽  
Acinar Cell ◽  
Cathepsin B ◽  
Cell System ◽  
Pancreatic Acinar Cell ◽  
In Vivo Model ◽  
Zymogen Granule ◽  
Zymogen Activation

Pathological activation of digestive zymogens within the pancreatic acinar cell initiates acute pancreatitis. Cytosolic events regulate this activation within intracellular compartments of unclear identity. In an in vivo model of acute pancreatitis, zymogen activation was detected in both zymogen granule-enriched and microsomal cellular fractions. To examine the mechanism of this activation in vitro, a reconstituted system was developed using pancreatic cytosol, a zymogen granule-enriched fraction, and a microsomal fraction. Addition of cytosol to either particulate fraction resulted in a prominent increase in both trypsin and chymotrypsin activities. The percentage of the pool of trypsinogen and chymotrypsinogen activated was about twofold and sixfold greater, respectively, in the microsomal than in the zymogen granule-enriched fraction. Activation of chymotrypsinogen but not trypsinogen was significantly enhanced by ATP (5 mM) but not by the inactive ATP analog AMP-PNP. The processing of procarboxypeptidase B to its mature form also demonstrated a requirement for ATP and cytosol. E64d, an inhibitor of cathepsin B, a thiol protease that can activate trypsin, completely inhibited trypsin activity but did not affect chymotrypsin activity or carboxypeptidase B generation. These studies demonstrate that both zymogen granule-enriched and microsomal fractions from the pancreas can support cytosol-dependent zymogen activation. A component of the activation of some zymogens, such as chymotrypsinogen and procarboxypeptidase, may depend on ATP but not on trypsin or cathepsin B.

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