scholarly journals Action of rat liver cathepsin L on collagen and other substrates.

1982 ◽  
Vol 201 (2) ◽  
pp. 367-372 ◽  
Author(s):  
H Kirschke ◽  
A A Kembhavi ◽  
P Bohley ◽  
A J Barrett
Keyword(s):  
Rat Liver ◽  
Active Site ◽  
Cathepsin B ◽  
Specific Activity ◽  
Cathepsin L ◽  
Purification Method ◽  
Mercury Derivative ◽  
Insoluble Collagen ◽  
And Storage

1. It has been found that cathepsin L is very susceptible to loss of activity through autolysis. When this is prevented by purification and storage of the enzyme as its mercury derivative, preparations are obtained with higher specific activity than previously. 2. Active-site titration shows, however, that even the new purification method does not give preparations in which the enzyme is 100% active. 3. Benzyloxycarbonylphenylalanylarginine 7-(4-methyl)coumarylamide has been discovered to be a very sensitive substrate for cathepsin L. Like all other known substrates for cathepsin L, however, it is also cleaved by cathepsin B. 4. Cathepsin L degrades insoluble collagen at pH 3.5 over 5-fold faster than at pH 6.0. The specific activity at pH 3.5 is 5-10-fold higher than that of cathepsin B (rat or human) or bovine spleen cathepsin N (‘collagenolytic cathepsin’). 5. Qualitatively, the action of cathepsin L on collagen is similar to that of cathepsins B and N, i.e. selective cleavage of terminal peptides leads to conversion of beta- and higher components mainly to alpha-chains.

Inhibitions of Cathepsin B and Cathepsin L by E-64 In Vivo. II. Incorporation of [3H]E-64 into Rat Liver Lysosomes In Vivo1

1982 ◽  
Vol 91 (4) ◽  
pp. 1373-1380 ◽  
Author(s):  
Seiichi HASHIDA ◽  
Eiki KOMINAMI ◽  
Nobuhiko KATUNUMA
Keyword(s):  
Rat Liver ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Liver Lysosomes ◽  
Rat Liver Lysosomes

scholarly journals Quantification of cathepsins B and L in cells

1998 ◽  
Vol 332 (2) ◽  
pp. 499-505 ◽  
Author(s):  
Ruye XING ◽  
Adele K. ADDINGTON ◽  
Robert W. MASON
Keyword(s):  
Active Site ◽  
Total Protein ◽  
Cathepsin B ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Cathepsin L ◽  
Breast Tumour ◽  
Cathepsin S ◽  
Cysteine Proteinases ◽  
Breast Tumour Cells

A method for quantifying active cysteine proteinases in mammalian cells has been developed using an active-site-directed inhibitor. Fluoren-9-ylmethoxycarbonyl(di-iodotyrosylalanyl)-diazomethane (Fmoc-[I2]Tyr-Ala-CHN2) was prepared and shown to react irreversibly with cathepsins B and L, but not with cathepsin S. The non- and mono-iodo forms of the inhibitor reacted with all three enzymes. These results demonstrate that, unlike cathepsins B and L, cathepsin S has a restricted S2-binding site that cannot accommodate the bulky di-iodotyrosine. Fmoc-[I2]Tyr-Ala-CHN2 was able to penetrate cells and react with active enzymes within the cells. A radiolabelled form of the inhibitor was synthesized and the concentration of functional inhibitor was established by titration with papain. This inhibitor was used to quantify active cysteine proteinases in cultured cells. Active cathepsin B was found to be expressed by all of the cells studied, consistently with a housekeeping role for this enzyme. Active forms of cathepsin L were also expressed by all of the cells, but in different quantities. Two additional proteins were labelled in some of the cells, and these may represent other non-characterized proteinases. Higher levels of active cathepsins B and L, and an unidentified protein of Mr 39000, were found in breast tumour cells that are invasive, compared with those that are not invasive. From the data obtained, it can be calculated that the concentrations of both active cathepsins B and L in lysosomes can be as high as 1 mM, each constituting up to 20% of total protein in the organelle. This new technique provides a more direct procedure for determining the proteolytic potential of cellular lysosomes.

scholarly journals A comparison of four cathepsins (B, L, N and S) with collagenolytic activity from rabbit spleen

1988 ◽  
Vol 256 (2) ◽  
pp. 433-440 ◽  
Author(s):  
R A Maciewicz ◽  
D J Etherington
Keyword(s):  
Cathepsin B ◽  
Specific Activity ◽  
Cathepsin L ◽  
Cross Reactivity ◽  
Enzymic Activity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Collagenolytic Activity ◽  
Cysteine Proteinases ◽  
Isoelectric Points ◽  
Multiple Charge

We have separated four cathepsins (B, L, N and S) from rabbit spleen. They are all collagen-degrading cysteine proteinases, with Mr values of 25,250, 23,500, 34,000 and 30,000 for cathepsin B, L, N and S respectively. Cathepsins B, N and S have isoelectric points of 5.4, 6.2 and 6.8 respectively, whereas cathepsin L exhibited multiple charge forms in the range 5.0-5.7. A comparison of their specific activity against a variety of protein and synthetic substrates shows many differences. These differences can be visually illustrated through isoelectric focusing and detection of enzymic activity with protein and synthetic-substrate overlays. By using an enzyme-linked immunosorbent assay based on the binding to chicken cystatin and detection with polyclonal and monoclonal antibodies to native cathepsins B and L, no cross-reactivity of the four native enzymes was observed. Studies on the co-operative or synergistic effect in degrading collagen indicated that, of the different combinations tested, only the combination of cathepsin B and N exhibited enhanced collagenolysis.

scholarly journals The nature of the collagenolytic cathepsin of rat liver and its distribution in other rat tissues

1972 ◽  
Vol 127 (4) ◽  
pp. 685-692 ◽  
Author(s):  
D. J. Etherington
Keyword(s):  
Rat Liver ◽  
Cathepsin B ◽  
Cathepsin D ◽  
Enzyme Inhibitors ◽  
The Other ◽  
Collagenolytic Activity ◽  
Rat Tissues ◽  
Phenylpyruvic Acid ◽  
Insoluble Collagen ◽  
Lysosomal Proteinases

1. An enzyme present in rat liver extracts degraded insoluble collagen maximally at pH3.5. Collagenolytic activity was more abundant in kidney, spleen and bone marrow and was also present in decreasing concentrations in ileum, lung, heart, skin and muscle. 2. The crude collagenolytic cathepsin was activated by cysteine and dithiothreitol, but not by 2-mercaptoethanol. Iodoacetamide, p-chloromercuribenzoate and 7-amino-1-chloro-3-l-tosylamidoheptan-2-one hydrochloride inhibited the enzyme. Zn2+, Fe3+ and Hg2+ ions were strongly inhibitory, but Ca2+, Co2+, Mg2+ and Fe2+ ions had little or no effect. EDTA was an activator of the enzyme. Inhibitors of cathepsin B were found to enhance collagenolysis, but phenylpyruvic acid, a cathepsin D inhibitor, inhibited the enzyme. Di-isopropyl phosphorofluoridate had no effect. 3. Collagenolysis at pH3.5 and 28°C was restricted to cleavage of the telopeptide region in insoluble collagen, and the material that was solubilized consisted mostly of α-chains. 4. The collagenolytic cathepsin was separated from cathepsins B2 and D by fractionation on Sephadex G-100 and a partial separation from cathepsin B1 was obtained by chromatography on DEAE-Sephadex. 5. The function of the collagenolytic cathepsin in the catabolism of collagen is discussed in relation to the action of the other lysosomal proteinases and the neutral collagenase.

Species variations amongst proteinases in liver lysosomes

1986 ◽  
Vol 6 (11) ◽  
pp. 991-997 ◽  
Author(s):  
Daniel Béchet ◽  
Alain Obled ◽  
Christiane Deval
Keyword(s):  
Rat Liver ◽  
Cathepsin B ◽  
Species Differences ◽  
Cathepsin L ◽  
Cathepsin H ◽  
Liver Lysosomes

Cathepsin B, H, L and D activities in liver lysosomes were compared between species. Although cathepsin B and D were detected in bovine, pig, chicken and rat liver, striking species differences were evident for cathepsin H and L. Cathepsin L activity was particularly high in chicken lysosomal extracts, but could not be detected in bovine and pig extracts. Whereas there was no significant cathepsin H activity in bovine extracts, rat liver lysosomal extracts contained large amounts of cathepsin H activity.

scholarly journals Probing the specificity of cysteine proteinases at subsites remote from the active site: analysis of P4, P3, P2′ and P3′ variations in extended substrates

2000 ◽  
Vol 347 (1) ◽  
pp. 123-129 ◽  
Author(s):  
Fernada C. Vieira PORTARO ◽  
Ana Beatriz F. SANTOS ◽  
Maria Helena S. CEZARI ◽  
Maria Aparecida JULIANO ◽  
Luiz JULIANO ◽  
...  
Keyword(s):  
Amino Acids ◽  
Significant Influence ◽  
Active Site ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Cysteine Proteinases ◽  
Aminobenzoic Acid ◽  
Site Analysis ◽  
Hydrophobic Amino Acids ◽  
Human Cathepsin

We have determined the kinetic parameters for the hydrolysis by papain, cathepsin B and cathepsin L of internally quenched fluorescent peptides derived from the lead peptides Abz-AAFRSAQ-EDDnp [in which Abz and EDDnp stand for o-aminobenzoic acid and N-(2,4-dinitrophenyl)ethylenediamine respectively], to map the specificity of S4 and S3 subsites, and Abz-AFRSAAQ-EDDnp, to identify the specificity of S2ʹ and S3ʹ. Abz and EDDnp were the fluorescent quencher pair. These two series of peptides were cleaved at the Arg-Ser bond and systematic modifications at P4, P3, P2ʹ and P3ʹ were made. The S4 to S2ʹ subsites had a significant influence on the hydrolytic efficiencies of the three enzymes. Only papain activity was observed to be dependent on S3ʹ, indicating that its binding site is larger than those of cathepsins B and L. Hydrophobic amino acids were accepted at S4, S3, S2ʹ and S3ʹ of the three enzymes. The best substrates for cathepsins L and B had Trp and Asn at P2ʹ respectively; variations at this position were less accepted by these enzymes. The best substrates for papain were peptides containing Trp, Tyr or Asn at P3ʹ. Basic residues at P3 and P4 were well accepted by cathepsin L and papain. We also explored the susceptibility of substrates Abz-AFRSXAQ-EDDnp, modified at P2ʹ (X), to human cathepsin B mutants from which one or two occluding loop contacts had been removed. The modifications at His111 (H111A) and His110 (H110A) of cathepsin B led to an increase in kcat values of one or two orders of magnitude. The hydrolytic efficiencies of these cathepsin B mutants became closer to those of papain or cathepsin L.

Inhibition of cathepsin L and B by haptoglobin, the haptoglobin–hemoglobin complex, and asialohaptoglobin. "In vitro" studies in the rat

1982 ◽  
Vol 60 (6) ◽  
pp. 631-637 ◽  
Author(s):  
M. Pagano ◽  
M. A. Nicola ◽  
R. Engler
Keyword(s):  
Rat Liver ◽  
Inflammatory Reaction ◽  
Cathepsin B ◽  
Cathepsin L ◽  
In Vitro Studies ◽  
The Other ◽  
Michaelis Constant ◽  
Thiol Proteinases ◽  
Thiol Proteinase

In broadening our research on the inhibition of cathepsin B (EC 3.4.22.1) by rat haptoglobin, we have used the haptoglobin–hemoglobin complex and asialohaptoglobin. The inhibition of cathepsin L (EC 3.4.22.15), another lysosomal thiol proteinase, by haptoglobin and its related molecules has also been investigated.With azocasein as substrate, both enzymes were inhibited by both haptoglobin and its related molecules. When azocasein was used as a substrate, the apparent Michaelis constant (Km, app.) for cathepsin L was 1 × 10−5 ± 0.4 × 10−5 M. When haptoglobin was added, the apparent inhibition constant (Ki, app.) was 3 × 10−8 ± 2.5 × 10−8 M.The results suggest that rat haptoglobin specifically inhibits lysosomal thiol proteinases and that it has a regulatory role in tissue proteolysis associated with the inflammatory reaction. On the other hand, these properties would seem to be peculiar to the systems rat haptoglobin – rat liver cathepsin B or L.

Inhibitions by E-64 Derivatives of Rat Liver Cathepsin B and Cathepsin L In Vitro and In Vivo 1

1980 ◽  
Vol 88 (6) ◽  
pp. 1805-1811 ◽  
Author(s):  
Seiichi HASHIDA ◽  
Takae TOWATARI ◽  
Eiki KOMINAMI ◽  
Nobuhiko KATUNUMA
Keyword(s):  
Rat Liver ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Derivatives Of

scholarly journals L-trans-Epoxysuccinyl-leucylamido(4-guanidino)butane (E-64) and its analogues as inhibitors of cysteine proteinases including cathepsins B, H and L

1982 ◽  
Vol 201 (1) ◽  
pp. 189-198 ◽  
Author(s):  
A J Barrett ◽  
A A Kembhavi ◽  
M A Brown ◽  
H Kirschke ◽  
C G Knight ◽  
...  
Keyword(s):  
Active Site ◽  
Cathepsin B ◽  
Cysteine Proteinase ◽  
Cathepsin L ◽  
Competitive Inhibitor ◽  
Serine Proteinases ◽  
Cysteine Proteinases ◽  
Leucocyte Elastase ◽  
Structural Analogues ◽  
Stoichiometric Reaction

1. L-trans-Epoxysuccinyl-leucylamido(4-guanidino)butane (E-64) at a concentration of 0.5 mM had no effect on the serine proteinases plasma kallikrein and leucocyte elastase or the metalloproteinases thermolysin and clostridial collagenase. In contrast, 10 muM-E-64 rapidly inactivated the cysteine proteinases cathepsins B, H and L and papain (t0.5 = 0.1-17.3s). The streptococcal cysteine proteinase reacted much more slowly, and there was no irreversible inactivation of clostripain. The cysteine-dependent exopeptidase dipeptidyl peptidase I was very slowly inactivated by E-64. 2. the active-site-directed nature of the interaction of cathepsin B and papain with E-64 was established by protection of the enzyme in the presence of the reversible competitive inhibitor leupeptin and by the stereospecificity for inhibition by the L as opposed to the D compound. 3. It was shown that the rapid stoichiometric reaction of the cysteine proteinases related to papain can be used to determine the operational molarity of solutions of the enzymes and thus to calibrate rate assays. 4. The apparent second-order rate constants for the inactivation of human cathepsins B and H and rat cathepsin L by a series of structural analogues of E-64 are reported, and compared with those for some other active-site-directed inhibitors of cysteine proteinases. 5. L-trans-Epoxysuccinyl-leucylamido(3-methyl)butane (Ep-475) was found to inhibit cathepsins B and L more rapidly than E-64. 6. Fumaryl-leucylamido(3-methyl)butane (Dc-11) was 100-fold less reactive than the corresponding epoxide, but was nevertheless about as effective as iodoacetate.

scholarly journals Elastinolytic activity of human cathepsin L

1986 ◽  
Vol 233 (3) ◽  
pp. 925-927 ◽  
Author(s):  
R W Mason ◽  
D A Johnson ◽  
A J Barrett ◽  
H A Chapman
Keyword(s):  
Cathepsin B ◽  
Specific Activity ◽  
Cathepsin L ◽  
Cysteine Proteinases ◽  
Pancreatic Elastase ◽  
Optimum Ph ◽  
Human Cathepsin ◽  
Hydrolysis Of

The hydrolysis of a tritiated elastin substrate by the human cysteine proteinases cathepsins B and L has been studied. Cathepsin L was found to be at least 100-fold more active on this substrate than cathepsin B. The specific activity of cathepsin L at pH 5.5 for hydrolysis of elastin was about the same as that of pig pancreatic elastase at its optimum pH of 8.8.

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