Purification and properties of different isoforms of bovine cathepsin B

1990 ◽  
Vol 68 (4) ◽  
pp. 822-826 ◽  
Author(s):  
Christiane Deval ◽  
Daniel Bechet ◽  
Alain Obled ◽  
Marc Ferrara
Keyword(s):  
Cathepsin B ◽  
Cathepsin L ◽  
Gel Filtration ◽  
Specific Inhibitor ◽  
Bovine Liver ◽  
Relative Mass ◽  
Low Concentrations ◽  
Purification And Properties ◽  
Different Populations ◽  
Rapid Purification

A rapid purification procedure is described for cathepsin B from bovine liver. After preparation of crude lysosomal extracts, the method only involves DEAE Zeta-Prep-Disk chromatography, gel filtration, and fast protein liquid chromatography on Mono-S column. Two active peaks (P1 and P2) of cathepsin B were distinguished. Both presented uncleaved (relative mass (Mr) 30 000) and cleaved (Mr 25 000 + Mr 5000) chains, but different isoforms as revealed by isoelectrofocusing. These two different populations of cathepsin B isoforms nevertheless exhibited similar enzymatic properties. Km and kcat were 114 μM and 52 s−1, and 125 μM and 75 s−1, for hydrolysis of Z-Arg-Arg-NMec by P1 and P2, respectively. Both were rapidly inhibited by low concentrations of E-64 or leupeptin, but were unaffected by cathepsin-L-specific inhibitor Z-Phe-Phe-CHN2.Key words: protein/enzyme purification, cathepsin B, isoforms, lysosomes.

scholarly journals The purification and properties of cathepsin L from rabbit liver

1984 ◽  
Vol 217 (1) ◽  
pp. 209-217 ◽  
Author(s):  
R W Mason ◽  
M A J Taylor ◽  
D J Etherington
Keyword(s):  
Cathepsin B ◽  
Cathepsin L ◽  
Gel Filtration ◽  
Subcellular Fractionation ◽  
Rabbit Liver ◽  
Purification And Properties ◽  
Chemical Inhibitors ◽  
Michaelis Constants ◽  
Ammonium Sulphate Fractionation ◽  
C 50

Cathepsin L was purified from rabbit liver by a method involving whole-tissue homogenization, pH precipitation, ammonium sulphate fractionation and chromatography on CM-Sephadex C-50, phenyl-Sepharose and Sephadex G-75. Pure enzyme was obtained without the necessity of laborious subcellular fractionation techniques. The Mr of the enzyme was determined to be 29 000 by gel filtration, and affinity for concanavalin A-Sepharose indicated that it was a glycoprotein. A novel technique for detection of enzyme activity in agarose isoelectrofocusing gels showed that the enzyme existed in multiple isoenzymic forms with pI values ranging from 5.0 to 5.9. The enzyme catalysed the hydrolysis of azocasein, collagen and Z-Phe-Arg-NMec (where Z and NMec indicate benzyloxycarbonyl and N-methylcoumarin derivative respectively) optimally at pH 5.2, 3.3 and 6.0 respectively. In addition, cathepsin L was found to degrade benzoyl-Phe-Val-Arg-NMec and 3-carboxypropionyl-Ala-Phe-Lys-NMec. However, cathepsin B also cleaved all of these substrates. One major difference between these two enzymes was in their Michaelis constants for Z-Phe-Arg-NMec; cathepsin B had Km 75 microM whereas that of cathepsin L was 0.7 microM. Cathepsin L was inhibited by all of the usual chemical inhibitors of thiol proteinases as well as the more specific inhibitors Z-Phe-Phe-CHN2, Z-Phe-Ala-CHN2, compound E-64 and compound Ep-475. Active-site titration with compound E-64 showed that the purified sample contained 80% active protein, which had kcat. 20s-1 for the substrate Z-Phe-Arg-NMec. Antibodies were raised to active cathepsin L, and these did not cross-react with cathepsin B, thus demonstrating that these two enzymes are immunologically distinct.

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 Purification and properties of the soluble carnitine palmitoyltransferase from bovine liver mitochondria

1987 ◽  
Vol 244 (2) ◽  
pp. 271-278 ◽  
Author(s):  
R R Ramsay ◽  
J P Derrick ◽  
A S Friend ◽  
P K Tubbs
Keyword(s):  
Glutamate Dehydrogenase ◽  
Gel Filtration ◽  
Random Order ◽  
Bovine Liver ◽  
Liver Mitochondria ◽  
Carnitine Palmitoyltransferase ◽  
Purification And Properties ◽  
Rapid Equilibrium ◽  
Variable Substrate ◽  
Myristoyl Coa

A new carnitine palmitoyltransferase (CPT) was purified to homogeneity from bovine liver mitochondria which were 96% free of peroxisomal contamination, as judged by catalase and glutamate dehydrogenase activities. The enzyme is easily removed from mitochondria, without the use of detergent. It is monomeric (Mr 63,500), unlike other preparations of CPT from mitochondria, and is most active with myristoyl-CoA and palmitoyl-CoA. The Km values are between 0.8 and 4 microM for a range of substrates from hexanoyl-CoA to stearoyl-CoA; these are much lower than values reported for other purified CPT preparations. The Km for L-carnitine is 185 microM measured with palmitoyl-CoA, and does not vary greatly with the chain length. This is also lower than the values reported for other CPT preparations, but higher than those cited for the medium-chain transferases. Kinetic and inhibitor studies were consistent with a rapid-equilibrium random-order mechanism. 2-Bromopalmitoyl-CoA, which is an inhibitor of the outer CPT, inhibited the enzyme competitively with palmitoyl-CoA as the variable substrate, when added without preincubation. If the enzyme was preincubated with 2-bromopalmitoyl-CoA and carnitine, the activity did not reappear after gel filtration of the protein. The inhibitor was bound in a 1:1 stoichiometry per subunit of enzyme.

scholarly journals Collagenolytic cysteine proteinases of bone tissue. Cathepsin B, (pro)cathepsin L and a cathepsin L-like 70 kDa proteinase

1991 ◽  
Vol 279 (1) ◽  
pp. 167-174 ◽  
Author(s):  
J M Delaissé ◽  
P Ledent ◽  
G Vaes
Keyword(s):  
Molecular Mass ◽  
Bone Tissue ◽  
Cathepsin B ◽  
Hydrophobic Interactions ◽  
Relative Rate ◽  
Cathepsin L ◽  
Gel Filtration ◽  
Cysteine Proteinases ◽  
Western Blots ◽  
Mouse Muscle

The aim of the work was to identify and characterize the cysteine proteinases of bone tissue, as these enzymes appear necessary for bone resorption. Three cysteine-dependent proteolytic activities were separated from a homogenate of mouse calvaria by a fractionation procedure involving (NH4)2SO4 precipitation, gel filtration and ion-exchange chromatography. The first two are typical cathepsins B and L with respect to (1) their reactivity with anti-(cathepsin B) and anti-(cathepsin L) antibodies respectively, (2) their relative rate constants for inhibition by benzyloxycarbonyl-Phe-Phe-CHN2 and L-3-carboxy-trans-2,3-epoxypropionyl-L-leucylamido-(4-guanid ino)butane and (3) their enzymic properties, such as the higher activities of cathepsin L against collagen and gelatin as compared with cathepsin B, and the fact that benzyloxycarbonyl-Arg-Arg 4-methoxy-2-naphthylamide is hydrolysed only by cathepsin B. Cathepsin L was mainly recovered in its precursor form, as indicated by its apparent 40 kDa molecular mass and its relative stability at pH 7.2. The third enzyme is a cathepsin L-like proteinase with an apparent molecular mass of 70 kDa. It is immunoprecipitated by anti-(cathepsin L) antibodies, and appears as the 25 kDa band of mature cathepsin L in Western blots. It further resembles (pro)cathepsin L with regard to its activities against synthetic substrates and proteins such as collagen, and with regard to its response to various inhibitors. However, unlike (pro)cathepsin L, it is eluted as a 70 kDa protein on gel filtration (even in the presence of 1% Brij or 1 M-NaCl), it is stable at pH values as high as 9, and it exhibits stronger affinity for phenyl-Sepharose. It might thus result from a strong complex between mature cathepsin L and another entity that confers stability at alkaline pH and favours hydrophobic interactions. This 70 kDa activity was also detected in mouse muscle and long bones of Ca(2+)-deficient chicks but not in mouse liver, spleen or kidney.

scholarly journals Studies on medium-chain fatty acyl-coenzyme A synthetase. Purification and properties

1968 ◽  
Vol 109 (2) ◽  
pp. 269-274 ◽  
Author(s):  
J. Bar-Tana ◽  
G. Rose ◽  
B. Shapiro
Keyword(s):  
Gel Filtration ◽  
Fatty Acyl ◽  
Enzyme Preparations ◽  
Medium Chain ◽  
Atp Formation ◽  
Low Concentrations ◽  
Purification And Properties ◽  
Fraction I ◽  
Acyl Coenzyme A ◽  
Relationship Of

1. Medium-chain fatty acyl-CoA synthetase (EC 6.2.1.2) was isolated by the method of Mahler, Wakil & Bock (1953) and the enzyme activity determined by the disappearance of CoA in the presence either of butyrate and ATP or of butyryl-AMP, as well as by ATP formation from butyryl-AMP and PPi. 2. Preincubation of the enzyme with CoA and ATP alone or together, followed by the removal of these substrates by gel filtration, caused a marked inhibition of ATP formation, contrary to results previously obtained with palmitoyl-CoA synthetase. 3. The effect of ATP on butyryl-AMP-dependent CoA disappearance was inconsistent. Low concentrations of ATP (0·1–0·5mm) always caused inhibition, whereas higher concentrations (5–10mm) activated in some enzyme preparations and inhibited in others. 4. This inconsistency was shown to be due to the presence of two enzyme fractions. Both fractions had similar activities when assayed by the butyryl-AMP- or butyrate-plus-ATP-dependent CoA disappearance. However, fraction I was activated by ATP as measured by butyryl-AMP-dependent CoA disappearance whereas fraction II was inhibited by it. Fraction I also catalysed ATP formation from butyryl-AMP and PPi whereas fraction II was lacking in such activity. 5. The relationship of these observations with respect to other known mechanisms of fatty acid-activating systems is discussed.

Platelet-Bound Prekallikrein Promotes Pro-Urokinase-Induced Clot Lysis: A Mechanism for Targeting the Factor XII Dependent Intrinsic Pathway of Fibrinolysis

1994 ◽  
Vol 71 (03) ◽  
pp. 347-352 ◽  
Author(s):  
Jean-Pierre Loza ◽  
Victor Gurewich ◽  
Michael Johnstone ◽  
Ralph Pannell
Keyword(s):  
Platelet Rich Plasma ◽  
Specific Inhibitor ◽  
Specific Effect ◽  
Clot Lysis ◽  
Factor Xii ◽  
Intrinsic Pathway ◽  
Clot Retraction ◽  
Enzymatic Mechanism ◽  
Low Concentrations ◽  
Factor Xiia

SummaryClots formed from platelet rich plasma were found to be lysed more readily by low concentrations of pro-urokinase (pro-UK) than clots formed from platelet poor plasma. This was not a non-specific effect since the reverse occurred with tissue plasminogen activator. A mechanical explanation due to platelet-mediated clot retraction was excluded by experiments in which retraction was inhibited with cyto-chalasin B. Therefore, a platelet-mediated enzymatic mechanism was postulated to explain the promotion of fibrinolysis. Casein autography of isolated platelets revealed a ≈ 90 kDa band of activity which comigrated with plasma prekallikrein (PK)/kallikrein, a known activator of pro-UK. Furthermore, treatment of platelets with plasma PK activator (PPA), consisting essentially of factor XIIa, induced activation of pro-UK and of chromomgenic substrate for kallikrein (S-2302). This activity corresponded to approximately 40-200 pM kallikrein per 10 8 washed and gel filtered platelets per ml. The activation of pro-UK by PPA-pretreated platelets was dose-dependent and inhibited by soybean trypsin inhibitor but not by bdellin, a specific inhibitor of plasmin, nor by the corn inhibitor of factor XIIa. Kinetic analysis of pro-UK activation by kallikrein showed promotion of the reaction by platelets. The KM of the reaction was reduced by platelets by ≈ 7-fold, while the kcat was essentially unchanged. In conclusion, PK was shown to be tightly associated with platelets where it can be activated by factor XIIa during clotting. The activation of pro-UK by platelet-bound kallikrein provides an explanation for the observed platelet mediated promotion of pro-UK-induced clot lysis. Since pro-UK and plasminogen have also been shown to be associated with platelets, the present findings suggest a mechanism by which the factor Xlla-dependent intrinsic pathway of fibrinolysis can be localized and targeted to a thrombus.

scholarly journals Differential Regulation of Cathepsin S and Cathepsin L in Interferon γ–treated Macrophages

2003 ◽  
Vol 197 (2) ◽  
pp. 169-179 ◽  
Author(s):  
Courtney Beers ◽  
Karen Honey ◽  
Susan Fink ◽  
Katherine Forbush ◽  
Alexander Rudensky
Keyword(s):  
Cathepsin L ◽  
Specific Inhibitor ◽  
Cell Types ◽  
Interferon Γ ◽  
Cathepsin S ◽  
Antigen Presenting Cell ◽  
Relative Contribution ◽  
Helper Cell Type ◽  
Ifn Γ ◽  
Antigen Presenting

Cathepsin S (catS) and cathepsin L (catL) mediate late stages of invariant chain (Ii) degradation in discrete antigen-presenting cell types. Macrophages (Mϕs) are unique in that they express both proteases and here we sought to determine the relative contribution of each enzyme. We observe that catL plays no significant role in Ii cleavage in interferon (IFN)-γ–stimulated Mϕs. In addition, our studies show that the level of catL activity is significantly decreased in Mϕs cultured in the presence of IFN-γ whereas catS activity increases. The decrease in catL activity upon cytokine treatment occurs despite the persistence of high levels of mature catL protein, suggesting that a specific inhibitor of the enzyme is up-regulated in IFN-γ–stimulated peritoneal Mϕs. Similar inhibition of activity is observed in dendritic cells engineered to overexpress catL. Such enzymatic inhibition in Mϕs exhibits only partial dependence upon Ii and therefore, other mechanisms of catL inhibition are regulated by IFN-γ. Thus, during a T helper cell type 1 immune response catL inhibition in Mϕs results in preferential usage of catS, such that major histocompatibility complex class II presentation by all bone marrow–derived antigen-presenting cell is regulated by catS.

scholarly journals A procedure for the rapid purification of Escherichia coli deoxyribonucleic acid-dependent ribonucleic acid polymerase (Short Communication)

1973 ◽  
Vol 133 (1) ◽  
pp. 201-203 ◽  
Author(s):  
Peter Humphries ◽  
David J. McConnell ◽  
Robert L. Gordon
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Short Communication ◽  
Gel Filtration ◽  
High Salt ◽  
Rapid Procedure ◽  
Complete Purification ◽  
Rapid Purification

A rapid procedure involving DNA–cellulose chromatography followed either by sedimentation in a high-salt glycerol gradient or by gel filtration is described for the complete purification of Escherichia coli DNA-dependent RNA polymerase.

The cysteine proteinases of Schistosoma mansoni cercariae

Parasitology ◽  
1997 ◽  
Vol 114 (2) ◽  
pp. 105-112 ◽  
Author(s):  
J. P. DALTON ◽  
K. A. CLOUGH ◽  
M. K. JONES ◽  
P. J. BRINDLEY
Keyword(s):  
Schistosoma Mansoni ◽  
Cathepsin B ◽  
Cathepsin L ◽  
Serine Proteinase ◽  
Skin Penetration ◽  
Scanning Electron Micrographs ◽  
Cysteine Proteinases ◽  
Similar Function ◽  
Substrate Preferences ◽  
Serine Proteinase Activity

Based on substrate preferences, cercariae of Schistosoma mansoni were seen to express both cathepsin L and cathepsin B cysteine proteinases, although the former activity was many -fold greater. Two cathepsin L activities identified in cercarial extracts by zymography co-migrated with activities in extracts of 3 h and 24 h schisotosomula and in extracts of adult worms. Since these enzymes have been implicated in haemoglob in digestion by adult worms, they may perform a similar function in schistosomula. Immunolocalization using scanning electron micrographs showed that cathepsin L and cathepsin B proteinases were present in the cercarial post-acetabular glands. In addition, cercarial serine proteinase activities considered to facilitate skin penetration efficiently cleaved the substrates Z-Gly-Pro-Arg-NHMec and Z-Gly-Pro-Lys-NHMec. Cercariae release most of this serine proteinase activity when induced to secrete the contents of their acetabular glands. In contrast, newly transformed 3 h and 24 h schistosomula did not express this activity.

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