scholarly journals IN VITRO EFFECT OF L-CARNITINE ON THE ACTIVITY OF LYSOSOMAL CYSTEINE PROTEASES AND THE STATE OF LYSOSOMAL MEMBRANE

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.

2015 ◽  
Vol 96 (5) ◽  
pp. 876-882
Author(s):  
M A Fomina ◽  
A M Kudlaeva

Aim. Assessment of direct influence of arginine on lysosomal cysteine proteases activity in vitro, in isolation as well as the stimulation of oxidative stress. Methods. The study was conducted on the 72 female conventional mature Wistar rats 280-320 g divided into 6 series of 12 rats each. Lysosome slurries were isolated from the liver of intact animals with a subsequent in vitro incubation in a sucrose solution, in the presence of L-arginine, as well as in the presence of L-arginine accompanied by the stimulation of oxidative stress. Samples of control groups were exposed in vitro with the addition of isolate and oxidant, respectively. Each batch was reproduced three times, incubation was performed at 37 °C in a water bath for 1, 2 and 4 hours. The activity of cathepsins B, L and H was studied using spectrofluorimetric method in two fractions - intra- and extralysosomal. Acid phosphatase activity was used as the main marker of membrane labialization. Results. One hour Incubation with 5 mM arginine in vitro led to inhibition of the cathepsin H activity and lysosomal membrane damage, however, further increase in incubation time led to its stabilization. In vitro exposure to 5 mM H2O2 caused an increase in activity of cathepsines B and L and the drop in the cathepsin H activity without obvious changes in the distribution of enzymes between extra and intralysosomal fractions. In a state of oxidative stress 2-hour in vitro incubation with 5 mM arginine reduced the permeability of lysosomal membranes for cathepsines B, H and L; while 4-hour incubation led to the destabilization of lysosomal membranes. Conclusion. The direct effect of arginine at a concentration of 5 mM within the 1,2 and 4-hour time intervals leads to a distinct change as a lysosomal cysteine protease activity and stability of lysosomal membranes.


2015 ◽  
Vol 96 (5) ◽  
pp. 819-824
Author(s):  
A S Il’icheva ◽  
M A Fomina

Aim. To study the activity of lysosomal cysteine proteases (cathepsins L, H) and acid phosphatase, changing of permeability, stability of myocardial lysosomal membranes in rats in experimental expressed hyperhomocysteinemia model, and while administering L-arginine and carnitine. Methods. The study was performed on male Wistar rats kept on standard vivarium conditions divided into three control and three experimental groups of 8 animals each. Experimental samples were administered methionine, or combination of L-arginine and carnitine with methionine. The level of serum homocysteine was measured by ELISA. Cathepsin L and H activity was detected by spectrofluorimetric method. Acid phosphatase activity was recorded using the «end point» method. Results. In the model of expressed hyperhomocysteinemia the increase of cathepsin H total activity due to both lysosomal and nonlysosomal fractions was found. These changes were observed along with the general increase of lysosomal membranes permeability. When correcting hyperhomocysteinemia with L-arginine and carnitine a decrease of cathepsin L and H levels was noted as well as positive effect on the myocardial lysosomal membranes stability. Conclusion. Expressed hyperhomocysteinemia is accompanied by statistically significant increase of both lysosomal and cytoplasmic fractions of the cathepsin H activity, indicating the lysosomal membranes permeabilisation phenomenon; L-carnitine and arginine correct hyperhomocysteinaemia effects, leading to cathepsin L and H reduced activity and having a stabilizing effect on the lysosomal membranes of cardiomyocytes.


2005 ◽  
Vol 386 (7) ◽  
pp. 699-704 ◽  
Author(s):  
Luciano Puzer ◽  
Juliana Vercesi ◽  
Marcio F.M. Alves ◽  
Nilana M.T. Barros ◽  
Mariana S. Araujo ◽  
...  

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.


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.


Parasitology ◽  
2004 ◽  
Vol 128 (5) ◽  
pp. 541-548 ◽  
Author(s):  
A. PARAMÁ ◽  
R. IGLESIAS ◽  
M. F. ÁLVAREZ ◽  
J. LEIRO ◽  
F. M. UBEIRA ◽  
...  

This study investigated protease activities in a crude extract andin vitroexcretion/secretion (E/S) products ofPhilasterides dicentrarchi, a ciliate fish parasite causing economically significant losses in aquaculture. Gelatin/SDS–PAGE analysis (pH 4, reducing conditions) detected 7 bands with gelatinolytic activity (approximate molecular weights 30–63 kDa) in the crude extract. The banding pattern observed in analysis of E/S products was practically identical, except for 1 low-molecular-weight band detected in the crude extract but not in the E/S products. In assays with synthetic peptidep-nitroanilide substrates, the crude extract hydrolysed substrates characteristic of cysteine proteases, namely Z-Arg-Arg pNA, Bz-Phe-Val-Arg pNA and Z-Phe-Arg pNA. These activities were strongly inhibited by the cysteine protease inhibitor E-64 and by Ac-Leu-Val-Lys aldehyde, a potent inhibitor of cysteine proteases of the cathepsin B protease subfamily. The proteases present in the crude extract degraded both type-I collagen and haemoglobinin vitro, consistent with roles in tissue invasion and nutrition respectively. Again, E-64 completely (collagen) or markedly (haemoglobin) inhibited this degradation. Finally, the histolytic activity of the ciliate in turbot fibroblast monolayers was strongly reduced in the presence of E-64, confirming the importance of secreted cysteine proteinases in the biology ofPhilasterides dicentrarchi.


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.


2011 ◽  
Vol 86 (1) ◽  
pp. 77-84 ◽  
Author(s):  
E.P. Masler

AbstractProteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyneincognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the large FMRF-amide like peptide (FLP) family in nematodes. Overall protease activity in P. redivivus was four- to fivefold greater than in either of the parasites, a result that might reflect developmental differences. Digestion of the M. incognita FLP KHEFVRFa (substrate Abz-KHEFVRF-Y(3-NO2)a) by M. incognita extract was sevenfold greater than with H. glycines extract and twofold greater than P. redivivus, suggesting species-specific preferences. Additional species differences were revealed upon screening 12 different protease inhibitors. Two substrates were used in the screen, Abz-KHEFVRF-Y(3-NO2)a and Abz-KPSFVRF-Y(3-NO2)a), which was digested equally by all three species. The effects of various inhibitor, substrate and extract source combinations on substrate digestion suggest that M. incognita differs significantly from P. redivivus and H. glycines in its complement of cysteine proteases, particularly cathepsin L-type protease.


2015 ◽  
Vol 60 (2) ◽  
pp. 797-805 ◽  
Author(s):  
Caroline Schad ◽  
Ulrike Baum ◽  
Benjamin Frank ◽  
Uwe Dietzel ◽  
Felix Mattern ◽  
...  

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.


2003 ◽  
Vol 2 (3) ◽  
pp. 501-509 ◽  
Author(s):  
Iris Bruchhaus ◽  
Brendan J. Loftus ◽  
Neil Hall ◽  
Egbert Tannich

ABSTRACT Cysteine proteases are known to be important pathogenicity factors of the protozoan parasite Entamoeba histolytica. So far, a total of eight genes coding for cysteine proteases have been identified in E. histolytica, two of which are absent in the closely related nonpathogenic species E. dispar. However, present knowledge is restricted to enzymes expressed during in vitro cultivation of the parasite, which might represent only a subset of the entire repertoire. Taking advantage of the current E. histolytica genome-sequencing efforts, we analyzed databases containing more than 99% of all ameba gene sequences for the presence of cysteine protease genes. A total of 20 full-length genes was identified (including all eight genes previously reported), which show 10 to 86% sequence identity. The various genes obviously originated from two separate ancestors since they form two distinct clades. Despite cathepsin B-like substrate specificities, all of the ameba polypeptides are structurally related to cathepsin L-like enzymes. None of the previously described enzymes but 7 of the 12 newly identified proteins are unique compared to cathepsins of higher eukaryotes in that they are predicted to have transmembrane or glycosylphosphatidylinositol anchor attachment domains. Southern blot analysis revealed that orthologous sequences for all of the newly identified proteases are present in E. dispar. Interestingly, the majority of the various cysteine protease genes are not expressed in E. histolytica or E. dispar trophozoites during in vitro cultivation. Therefore, it is likely that at least some of these enzymes are required for infection of the human host and/or for completion of the parasite life cycle.


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