scholarly journals Glycosylation of procathepsin L does not account for species molecular-mass differences and is not required for proteolytic activity

1989 ◽  
Vol 262 (3) ◽  
pp. 931-938 ◽  
Author(s):  
S M Smith ◽  
S E Kane ◽  
S Gal ◽  
R W Mason ◽  
M M Gottesman

Cathepsin L is a major lysosomal cysteine proteinase in mouse and human cells. Despite similar predicted molecular masses, procathepsin L in these two species migrates on SDS/polyacrylamide gels with apparent molecular masses of 39 kDa and 42 kDa respectively. To determine if glycosylation differences account for this discrepancy, and to ascertain whether glycosylation is essential for enzymic activity, mouse and human procathepsins L were expressed at high concentrations in mouse NIH 3T3 cells or in human A431 cells after DNA-mediated transfection of cloned DNAs for these enzymes. In pulse-chase studies, human procathepsin L transfectants synthesized and secreted large amounts of enzymically active 42 kDa proenzyme and processed it into 34 kDa and 26 kDa intracellular peptides, a pattern of secretion and processing similar to that seen with endogenous or transfected mouse procathepsin L. Both translation of cloned procathepsin L cDNAs in vitro and Endoglycosidase H treatment of 39 kDa mouse and 42 kDa human procathepsin L resulted in non-glycosylated proteins 2 kDa lower in molecular mass than the untreated proteins for both species. This suggests that glycosylation differences are not responsible for the molecular-mass disparity between the two species. Moreover, Endoglycosidase H-treated mouse enzyme retained full proteolytic activity, indicating that glycosylation of cathepsin L is not essential for enzymic function.

1990 ◽  
Vol 272 (1) ◽  
pp. 39-44 ◽  
Author(s):  
A Salminen ◽  
M M Gottesman

The lysosomal cysteine proteinase cathepsin L is synthesized in cultured mouse NIH 3T3 cells as a 39 kDa precursor and processed intracellularly into active 29 kDa and 20 kDa + 5 kDa lysosomal forms. Addition to culture media of the peptidyl aldehyde leupeptin, a non-covalent inhibitor of cathepsin L, results in the accumulation of the 20 kDa mature form of the enzyme, resulting in increased activity of cathepsin L as measured in an in vitro assay system in the absence of leupeptin. The more potent irreversible cathepsin L inhibitors benzyloxycarbonyl-Phe-Ala-diazomethane and L-transepoxysuccinyl-L-leucylamino-(4-guanidino)butane, when added to living cells at low concentrations, result in accumulation of all partially processed forms of cathepsin L, especially the 29 kDa form, suggesting that cathepsin L is responsible for its own processing. Exogenous procathepsin L introduced into CHO cells by endocytosis via the mannose 6-phosphate receptor is processed in a manner similar to endogenous procathepsin L. We conclude that the major intracellular pathway for processing of procathepsin L, either endogenous or exogenous, probably requires active cathepsin L.


1987 ◽  
Vol 65 (10) ◽  
pp. 921-924 ◽  
Author(s):  
Gilles Paradis ◽  
Jean Y. Dubé ◽  
Pierre Chapdelaine ◽  
Roland R. Tremblay

Poly(A)+ RNA was isolated from human prostatic tissue and translated in vitro in a rabbit reticulocyte lysate translation assay. Acid phosphatase labeled with [35S]methionine was immunoprecipitated with an antibody against seminal plasma acid phosphatase. Two-dimensional polyacrylamide gel electrophoresis of the immunoprecipitate, followed by fluorography, revealed the presence of two spots (one major and one minor), both having a molecular mass of 43 kilodaltons (kDa) and an isoelectric point higher than mature acid phosphatase. Addition of canine pancreatic membranes to the translation assay resulted in the formation of four immunoprecipitable spots with molecular masses ranging from 43 to 49 kDa on one-dimensional gels. These spots probably represent acid phosphatases containing one to four core sugar groups, since after the addition of endoglycosidase H the molecular mass heterogeneity was abolished and we observed only one major band with a molecular mass (41 kDa) slightly lower than the ones of the primary translation product. These results suggest that human prostatic acid phosphatases are synthesized as two 43-kDa preproteins, which are further processed to 41-kDa proteins by removal of their signal peptide. Heterogeneity of the native protein arises mostly from glycosylation at four sites and not from differences in the amino acid sequence of the various forms.


1982 ◽  
Vol 205 (2) ◽  
pp. 295-302 ◽  
Author(s):  
A D Gounaris ◽  
E E Slater

Cysteine-proteinase activity was observed in homogenates of human-cadaver renal cortex. This activity co-purified with renin enzymic activity until separation by aminohexyl-Sepharose-pepstatin affinity chromatography. The cysteine proteinase was purified 1780-fold after the following successive chromatographic procedures: Sephadex G-75, DEAE-cellulose DE-52, and an organomercurial affinity resin. The proteinase activity was dependent upon activation by thiol-containing compounds such as dithiothreitol, as well as by EDTA, and was inhibited by the thiol-group-specific alkylating reagents iodoacetic acid and N-ethylmaleimide. DE-52 cellulose chromatography resolved the cysteine proteinase into two components. On the basis of molecular size (26 000 daltons), activity as a function of pH, stability as a function of pH, substrate specificity and thermal lability, the major component (95%) has been identified as cathepsin B. The DE-52 cellulose elution pattern of the minor component (5%) is suggestive of cathepsin H [Schwartz & Barrett (1980) Biochem. J. 191, 487-497] Enzymic activity was determined with synthetic substrates, in particular alpha-N-benzoyl-DL-arginine 2-naphthylamide (Bz-Arg-NNap), thus precluding the detection of cathepsin L [Kirschke, Langner, Wiederanders, Ansorge, Bohley & Broghammer (1976) Acta Biol. Med. Germ. 35, 285-299]. Inhibition by dimethyl sulphoxide was observed in the determination of Km = 7.0 +/- 0.4 mM for the substrate Bz-Arg-NNap, and care must therefore be taken in the preparation of substrate solutions.


2017 ◽  
Vol 25 (1) ◽  
pp. 14-20 ◽  
Author(s):  
M A. Fomina ◽  
A M. Kudlaeva ◽  
A N. Ryabkov

The influence of L-carnitine in vitro on the lysosomal cysteine proteinase activity and stability of the lysosomal membrane of the liver homogenates of intact sexually Mature female rats of Wistar line weighing 280-330 g were studied. In the experimental groups isolated lysosomes were incubated in vitro in a solution of L-carnitine during 1, 2 and 4 hours, in the control groups in vitro incubation was carried out in a medium of isolating solution. The activity of ca-thepsins B, L and H was investigated by spectrofluorimetric method of Barrett & Kirschke in two fractions - lysosomal and outside of lysosomes. The activity of acid phosphatase was used as the main marker of a membrane labilization. In vitro incubation of lysosomes showed that carnitine at a concentration of 5 mM increases the total activity of cathepsin B in a one-hour incubation at 73,2% (p=0,008), cathepsin L in a two- and four-hour incubation - at 77,7% (p=0,005) and 42,3% (p=0,013) respectively, and reduces the overall activity of the cathepsin H in a one-hour incubation at 200,0% (p=0,008), in a two-hour - by 67,9% (p=0,05), in a four-hour -27,1% (p=0,02). In addition, incubation in 5 mM L-carnitine solution leads to an increase of unsedimentable activity and fall sedimentaries activity for cathepsin L in a two-hour, and for acid phosphatase - in a two - and four-hour exposure. 5 mM L-carnitine in one - and two-hour incubation stabilizes lysosomal membrane (whereas increase in incubation time up to 4 hours leads to its damage) and increases the selective permeability of the lysosomal membrane for the studied cathepsins, to the greatest extent - for cathepsin H.


Author(s):  
Niranjan Kumar ◽  
Bhupamani Das ◽  
Mehul M. Jadav ◽  
Jayesh B. Solanki

The objective of this study was to characterize Haemonchus contortus antigens, and to standardize and evaluate indirect plate and dot-ELISA using homologous antigens in the small ruminants. Electrophoretic separation of somatic antigen in reducing condition on 15% polyacrylamide gel resolved into 16 proteins of molecular weight ranging from 14-100 kDa. Two step ethanolic extraction of the supernatant of in-vitro culture of H. contortus yielded excretory-secretory (E-S) antigen/ cathepsin L cysteine proteinase of molecular weight 28 kDa. The animals (Goats=103; Sheep=91) were broadly kept into post-mortem (PM) and faecal examined groups and further sub-grouped based on mono or multiply helminths infection. At many occasion, the somatic antigen found to cross reacts with other helminths parasites thus minimizing the specificity of the selected tests and antigens. There was no any direct correlation between the parasites load and ELISA reactivity pattern. The prevalence rate of haemonchosis was 55.7 (34/61) in goats/ 47.6 (40/84) % in sheep as per PM examination while it was 45.63 (47/103) in goats/ 41.76% (38/91) in sheep and 36.89 (38/103) in goats/ 35.16% (32/91) in sheep using E-S antigen based plate and dot-ELISA, respectively. With E-S antigen, the overall % sensitivity, specificity, positive and negative predictive values of plate-ELISA was 89.74 (goats)/ 80.95 (sheep), 81.25 (goats)/ 91.84 (sheep), 74.47 (goats)/ 89.47 (sheep), 92.86 (goats)/ 84.91 (sheep), respectively while for dot-ELISA it was 66.67 (goats)/ 61.9 (sheep), 81.25 (goats)/ 87.76 (sheep), 68.42 (goats)/ 81.25 (sheep), 80 (goats)/ 72.88 (sheep), respectively, so the tests and E-S antigen can be recommended for the detection haemonchosis in the small ruminants.


1991 ◽  
Vol 260 (2) ◽  
pp. R314-R320 ◽  
Author(s):  
H. Yokozeki ◽  
T. Hibino ◽  
T. Takemura ◽  
K. Sato

Although cysteine proteinases have been reported to be present in human eccrine sweat, their endogenous inhibitors, cysteine proteinase inhibitors (CPIs), have remained unstudied. We now present evidence that CPIs are indeed a true ingredient of human eccrine sweat. Sweat induced in sauna was collected over a Vaseline barrier placed on the skin to minimize epidermal contamination. The absence of major epidermal contamination of the sweat was further ensured by monitoring an epidermal marker, high-molecular-mass aminopeptidase. Sweat CPI was purified sequentially by chromatography with Sephacryl S-200, carboxymethylated papain-Sepharose, and anion-exchange Mono Q fast-protein liquid chromatography columns. Sweat CPI has a molecular mass of approximately 15 kDa, is stable for temperature (up to 80 degrees C) and pH (from 3 to 10), and inhibits papain, ficin, and sweat cathepsin B- and H-like enzymes. Sweat CPI may be of sweat gland origin because 1) the rate of CPI output in sweat (CPI concentration x sweat rate) is constant over 45 min; 2) antibody against epidermal CPI, which cross-reacts with sweat CPI, localized immunoreactivity in the sweat duct; 3) CPI activity was present in the glandular extracts of control and methacholine-stimulated (for 1 h in vitro) human sweat glands; and 4) the peaks of CPI activity in the glandular extract and sweat CPI were both eluted (by high-pressure liquid chromatography) at around 15 kDa. Sweat CPI may be very similar to epidermal CPI (which belongs to the stefin family of CPIs) because of many shared characteristics. The identity and function of sweat CPI remain to be studied.


1984 ◽  
Vol 220 (1) ◽  
pp. 147-155 ◽  
Author(s):  
M Pagano ◽  
F Esnard ◽  
R Engler ◽  
F Gauthier

The inhibition of human liver cathepsin L by two specific proteinase inhibitors present in human serum, namely alpha 2 cysteine-proteinase inhibitor and the low-Mr cysteine-proteinase inhibitor, was studied. Kinetic parameters, including inhibition constants (Ki) and rate constants for association and dissociation (k+1 and K-1), were determined. The values found are consistent with a possible physiological function of these inhibitors to control cathepsin L activity. Furthermore, a transfer of active proteinase from the complex with either cysteine-proteinase inhibitor species to alpha 2-macroglobulin was demonstrated in vitro. Given the rate of dissociation of both cathepsin-L-cysteine-proteinase inhibitor complexes, a function of transitory inhibitor can therefore be hypothesized for these proteins and might then provide an explanation of the clearance of lysosomal proteinases.


Parasitology ◽  
2005 ◽  
Vol 131 (3) ◽  
pp. 411-416 ◽  
Author(s):  
S. BAIG ◽  
R. T. DAMIAN ◽  
J. L. MOLINARI ◽  
P. TATO ◽  
J. MORALES-MONTOR ◽  
...  

Infection of the central nervous system byTaenia soliumcysticerci is the cause of human neurocysticercosis, a major neurological infection in the Third World and an emerging infectious disease in the United States. We previously isolated a cysteine proteinase from cysticerci ofTaenia crassicepsand demonstrated that it degrades human IgGin vitro. We have now isolated a 48 kDa thiol-dependent proteinase fromT. solium. TheT. soliumenzyme also degrades human IgG, but does not significantly degrade albumin. IgG degradation was inhibited by cysteine proteinase inhibitors, but not significantly by inhibitors of aspartic, serine, or metalloproteinases. The peptide substrate specificity and pH optimum resemble cathepsin L. The Km for the peptide substrate Z-Phe-Arg-AFC was calculated to be 7·0×10−6M, the Kcat was 1·98×105s−1, and the Kcat/Km 2·84×109M−1s−1, a value which is within the diffusion control limit for highly catalytic enzymes. We propose that immunoglobulin degradation by theT. soliumcysteine proteinase may play a key role in the host-parasite interface and could be employed as a target for chemotherapy.


Parasitology ◽  
1994 ◽  
Vol 108 (5) ◽  
pp. 595-601 ◽  
Author(s):  
S. J. Hawthorne ◽  
D. W. Halton ◽  
B. Walker

SummaryThe excreted/secreted proteinases ofHaplometra cylindraceamaintainedin vitro, were found to hydrolyse the fluorogenic substrates, Z-ArgArg-NHMec and Z-PheArg-NHMec. This activity was shown to be typically that of cysteine proteinases, as turn-over of both substrates could be blocked by pre-incubation with peptidyl diazomethyl ketones. The biotinylated affinity reagent, biotin-Phe Ala-DMK, used in combination with Z-PheTyr(OBut)-DMK, was employed for the labelling and characterization of these cysteine proteinase activities. Three cathepsin B-like species were detected, with molecular weights of 48, 22–23 and 14 kDa, together with a cathepsin L-like enzyme, with a molecular weight of 55 kDa. The proteinases were also found to have hydrolytic activity towards the substrate, Z-GlyGlyArg-NHMec, which could be blocked by pre-incubation with either of the serine proteinase-selective reagents, Z-ArgP(OPh)2, or biotin-LysP(OPh)2, showing the activity to be trypsin-like. Using the biotinylated affinity label to characterize the trypsin-like enzymes revealed two molecular species with molecular weights of 20 and 24 kDa.


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