Camel Liver Research Articles

Comparative transcriptome analysis of liver tissues in bactrian camel (Camelus Bactrianus)

In the present study, comparative transcriptome sequencing was used to compare liver tissue transcriptome profiles between domestic bactrian camel (BCL), cattle (CL) and sheep (SL). The RNA-seq data from these two groups revealed that 3254 genes were differentially expressed between the BCL and CL groups, 2426 genes were found to differ significantly in expressional levels between BCL and SL. Pathway analysis revealed that the differentially expressed genes between the BCL and CL belong to non-alcoholic liver disease, bile secretion, as well as metabolic related pathway such as fatty acid metabolism and degradation, xenobiotics by cytochrome P450, drug metabolism-cytochrome P450, and drug metabolism-other enzymes; between the BCL and SL groups. A complete dataset of bactrian camel liver tissue using RNA-seq will facilitate the understanding of the unique biological characteristics of bactrian camels and supply essential information towards further studies on the genomes of bactrian camel and other ralated mammals.

Determination of Heavy Metal Residues in Slaughtered Camels at Sokoto and Gusau Modern Abattoirs, Nigeria.

Background.Heavy metals can pose health risks to both animals and humans. Objectives. To determine the concentrations of lead (Pb), cadmium (Cd), and chromium (Cr) in samples taken from the kidney, liver, muscle, hide, and blood of camels slaughtered at both Sokoto and Gusau modern abattoirs.Methods.The concentrations of Pb, Cd, and Cr in tissues and organs of camels slaughtered at both Sokoto and Gusau modern abattoirs were determined using atomic absorption spectrophotometry. A total of 120 samples were collected.Results.All the samples collected tested positive for Pb, Cd and Cr. The overall mean concentrations of Pb, Cd and Cr in tissues and organs of slaughtered camels at Sokoto modern abattoir ranged from 0.11 mg/kg to 0.35 mg/kg, 0.05 to 0.8 mg/kg and 0.41 to 0.59 mg/kg, respectively, while at Gusau modern abattoir, the overall mean concentrations of Pb, Cd and Cr ranged from 0.20 mg/kg to 1.17 mg/kg, 0.01 to 0.14 mg/kg and 0.13 to 0.51 mg/kg, respectively.Discussion.The concentration of Pb in the tissues and organs of camels slaughtered at Gusau modern abattoir was high compared to in camels slaughtered at Sokoto modern abattoir, while the concentrations of Cd and Cr in the tissues and organs of camels slaughtered at Sokoto modern abattoir were high compared to those in tissues and organs of camels slaughtered at Gusau modern abattoir. There were significant differences (P<0.05) in the concentration of Pb, Cd, and Cr in samples taken from the kidney, liver, muscle, hide, and blood of slaughtered camels at both Sokoto and Gusau.Conclusions.Camels slaughtered at both Sokoto and Gusau modern abattoirs were exposed to Pb, Cd, and Cr.The tissues and organs of camels slaughtered at both Sokoto and Gusau contain Pb, Cd, and Cr. Prolonged exposure through consumption of these tissues and organs should be avoided.Competing Interests.The authors declare no competing financial interests.

The comparative study of expression and distribution of cyp2j gene in different part of the digestive system in bactrian camel

This study was conducted to investigate the expression and distribution of CYP2J gene in different parts of the digestive system in Bactrian camel and to explore the related clues between the CYP2J genes and the characteristics of salt-sensitive hypertension of Bactrian camels. Firstly, the primers were designed according to predictive sequences (XM-006176094.1) of Bactrian camel CYP2J genes and ACTB of Bactrian camel, as well as Mongolian cattle CYP2J genes (NM-001077210.1) and ACTB Mongolian cattle, then the CYP2J genes were amplified by SYBR Green Real-Time PCR using ACTB as reference gene. Secondly, the relative quantitative method of 2−ΔΔCT was used to process the data and the expression level of CYP2J gene in 7 parts of digestive system including liver, spleen, caecum, colon, jejunum, ileum and duodenum of Bactrian camel and Mongolian cattle was comparatively analysed. The result showed that CYP2J gene was highly expressed in the liver of Bactrian camel and followed by colon, duodenum, ileum, jejunum and caecum. However, in Mongolian cattle, the relative expression of CYP2J gene was highest in pancreas, followed by liver, duodenum, ileum, jejunum, colon and caecum. Furthermore, the relative expression level of CYP2J gene in Bactrian camels’ liver, pancreas, colon and duodenum was significantly higher than that of in corresponding parts of the digestive system in Mongolian cattle. Therefore, the expression and distribution of CYP2J gene in different parts of digestive system of Bactrian camel was significantly different from Mongolian cattle, however, these two species are closest in degree of evolution.

Partial Purification and Some Interesting Properties of Glutathione Peroxidase from Liver of Camel (Camelus dromedarius)

Climate change and increasing temperatures are global concerns. Well adapted to desert life, the camel (Camelus dromedarius) lives most of its life under high environmental stress and represents an ideal model for studying desert adaptation among mammals. Glutathione peroxidase is the principal antioxidant defense system capable of protecting cells from oxidative stress. Glutathione Peroxidase from camel liver was purified (11.64-fold purification with 1.73% yield) and characterized The molecular weight of the enzyme was estimated to be about 69 kDa by gel filtration and 34 kDa by SDS-PAGE, implying dimeric structure of the protein. An optimum temperature of 47°C and an optimum pH of 7.8 were found. This enzyme is a typical SH-enzyme that is inhibited by D,L-dithiothreitol and β-mercaptoethanol and sensitive to bivalent cations. The enzyme had common specificity toward hydroperoxides and high specificity for reduced glutathione. The Km and Vmax values for hydrogen peroxide and reduced glutathione were 0.57 and 2.10 mM and 1.11 and 0.87 U/mg, respectively. The purified enzyme contained 16 ng of selenium per mg of protein. Our results show that the camel glutathione peroxidse exhibits properties different of those reported for other mammalian species. Lower molecular weight, homodimeric structure, higher optimum temperature, relatively low optimum pH, high affinity for hydrogen peroxide at low concentration of reduced glutathione and very low content of selenium could be explained by adaptation of the camel to living in the desert under intense environmental stress.

Condemened Meat and Offal from Different Slaughtered Animals at Two Different Environments

Objective: Study conducted to evaluate the meat, liver and kidney condemnation of sheep, cattle, and camel around 2017 slaughtered animals between upper and lower Egypt “Ismailia and Elkharga slaughterhouses”. Methods: The prevalence of the gross lesions of meat, liver and kidney was collected all over the examined time of the study for detection of abnormalities at ante-mortem and post-mortem inspections. Results: Ismailia slaughterhouse recorded about; 9788 slaughtered animal as following; (1890 (19.3%) sheep, 7652 (78.2%) cattle, 246 (2.5%) camel) while in Elkharga slaughterhouse recorded about; 2299 slaughtered animal as following; (32 (1.39%) sheep, 2251 (97.92%) cattle, 16 (0.69%) camel). Results revealed that beef was 1377360 Kg (93.0%) the first selection by Ismailia population followed by chevon (56700 Kg) 3.8% then camel meat (46740 Kg) 3.2%. While, in New valley beef were the highest consumed 405180 kg (99.02%), followed by camel meat 3040 (0.75%) then chevon 960 kg (0.23%). The total condemned meat from sheep, cattle, and camel were 134 (8.7%), 1350 (87.7%) and 56 (3.6%) Kg respectively. While, about 1449 kg of meat was condemned at Elkharga slaughterhouse as following; 21 (1.45%), 1391 (95.995) and 37 (2.56%) from sheep, cattle, and camels respectively. Gross liver lesions in sheep, cattle, and camel were 18 (7.9%), 197 (86.4%) and 13 (5.7%) lesions respectively at Ismailia slaughterhouse. Gross kidney lesions of sheep, cattle and camel were 2 (4.0%), 48 (96.0%) and 0 (0.0%) lesions respectively. On the other hands, the gross liver lesion recorded at Elkharga slaughterhouse was about 1 (2.7%), 36 (97.29%) and 0 (0.0%) of sheep, cattle, and camels respectively. While the kidney gross lesions were 0 (0.0%) for sheep and camel and 7 (100%) for cattle carcasses. Conclusion: Study recorded lower incidence of condemnation in Elkharga than Ismailia carcasses due to sunny, hot weather and dry environment that inhibit almost causative agents.

Unique properties of arginase purified from camel liver cytosol

Arginase (ARG) is an enzyme involved in urea cycle, where it catalyzes the hydrolysis of L-arginine into L-ornithine and urea. Since there is no information about the isolation and purification of ARG from camel liver, this investigation was designed to purify and characterize ARG from camel liver and compare its molecular and kinetic properties with that reported from other species. Camel liver arginase (CL-ARG) was purified to homogeneity using heat denaturation followed by ammonium sulphate precipitation with a combination of DEAE-cellulose, SP-Sepharose and Sephadex G 100-120 chromatography columns. The specific activity of CL-ARG was increased to 18,485 units/mg proteins with 23.5-fold purification over crude homogenate. It was observed that CL-ARG showed a similarity with other species such as behaviour on DEAE-cellulose column, kinetics of inhibition, necessity for metal ions as cofactor, and alkaline optimum pH. On the contrary, CL-ARG differed in its molecular weight (180kDa), oligomeric protein structure, slightly neutral-alkaline pI value (7.7), Km value (7.1mM), optimum pH (9, 10.7), and higher optimum temperature (70°C). In conclusion, this study investigated the properties of CL-ARG via a simple and reproducible purification procedure and provided valuable information for its production from available source in Egypt for medical and industrial purposes.

Purification of camel liver catalase by zinc chelate affinity chromatography and pH gradient elution: An enzyme with interesting properties.

Climate change and increasing temperatures are global concerns. Camel (Camelus dromedarius) lives most of its life under high environmental stress in the desert and represent ideal model for studying desert adaptation among mammals. Catalase plays a key role in protecting cells against oxidative stress. For the first time, catalase from camel liver was purified to homogeneity by zinc chelate affinity chromatography using pH gradient elution, a better separation was obtained. A purification fold of 201.81 with 1.17% yield and a high specific activity of 1132539.37U/mg were obtained. The native enzyme had a molecular weight of 268kDa and was composed of four subunits of equal size (65kDa). The enzyme showed optimal activity at a temperature of 45°C and pH 7.2. Thiol reagents, β-Mercaptoethanol and D,L-Dithiothreitol, inhibited the enzyme activity. The enzyme was inhibited by Al3+, Cd2+ and Mg2+, whereas Ca2+, Co2+ and Ni2+ stimulated the catalase activity. Reduced glutathione has no effect on catalase activity. The Km and Vmax of the enzyme for hydrogen peroxide were 37.31mM and 6185157U/mg, respectively. Sodium azide inhibited the enzyme noncompetitively with Ki value of 14.43μM, the IC50 was found to be 16.71μM. The properties of camel catalase were different comparing to those of mammalian species. Relatively higher molecular weight, higher optimum temperature, protection of reduced glutathione from hydrogen peroxide oxidation and higher affinity for hydrogen peroxide and sodium azide, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert.

Investigation of different enzyme markers in some pathological disorders of the dromedary camels in comparison with other species.

Abstract Camel adaptation to its arid and semi-arid environment and its genetic make-up created some differences in its enzyme systems compared with other domestic animals. The camel is similar to ruminants in most of the diagnostic enzymes used to evaluate liver functions. However, some differences from other domestic species were noticed in muscular, neuromuscular, pancreatic, bone, drug metabolizing, metalo and antioxidant enzymes in serum and/or tissue. The drug-metabolizing enzymes are low in camel liver and it looks that it has not developed a potent drug metabolizing enzyme system as xenobiotic are low in its natural habitat although its liver was found to be potent in the detoxification of some carcinogens. The low plasma pseudcholinesterase in camel compared with ruminants may explain why it is more vulnerable and less adapted to the toxicity of the organophosphorus compound in agricultural pesticides and herbicides; not previously found in its arid and semiarid habitat. The antioxidant system in the camel looks to be very potent to prevent or reduce oxidative stress which may be another adaptation mechanism to its natural environment. More research is required in serum and tissue enzymes in the camel. There is a great variation in a reference range of diagnostic enzymes in camels. This is due to differences in pre-analytical, analytical and post-analytical procedures and the number of specimens used to define the reference range. Indeed, different laboratories may have the different analytical equipment, different reagents and sources, different specimen's collection and handling procedures, different analytical methods and validation, different storage facilities, different staff qualifications, experience and quality background and the presence or not of a proficiency testing program. Moreover, the physiological, pathological, nutritional, genetical, environmental and geographical factors are of paramount importance in camel enzyme activity. Specifically, the effects of season, sex, age, breed and stage of lactation were emphasized in comparison with other species. Therefore, laboratories should establish their own reference values.

Purification and properties of an alanine aminopeptidase from camel liver

Purification and properties of an alanine aminopeptidase from camel liver

Gene cloning and expression analysis of mitochondrial glutathione reductase from Arabian camel (Camelus dromedarius) liver in Escherichia coli

Glutathione reductase (GR) is highly conserved among diverse taxa and has important biochemical functions. These functions may facilitate survival in harsh conditions, but the role of GR from the liver of the Arabian camel (Camelus dromedarius) is unknown. In this study, the mitochondrial glutathione reductase gene (Gsr) from C. dromedarius liver was cloned and highly expressed in Escherichia coli (Jm109) to gain insight into GR functions in the liver. After amplification of the cDNA encoding the functional unit of Gsr (1.2 kb), the products were cloned into the PGEM-T Easy and PET28a vectors. Gsr expression was confirmed using an immunoblotting technique (45 kDa). Recombinant GR was purified to homogeneity using Ni-NTA resins, with an overall yield of 7.23% and a specific activity of 0.3063 U/mg. The optimum pH of recombinant GR was 7 and the optimum temperature was 35 °C in 50 mM K3PO4 buffer. The Michaelis constant, Km, for the substrates glutathione disulfide (GSSG) and NADPH was 45.6 μM and 63.5 μM, respectively; moreover, maximal velocity (Vmax) values were 3.969 x 10-2 U/mg and 1.497 x 10-1 U/mg. This partial characterization of camel liver GR extends our insight into the ability of camels to cope with harsh environmental conditions.

Molecular characterization of Cysticercus tenuicollis of slaughtered livestock in Upper Egypt governorates

ObjectiveTo present the molecular characterization of Cysticercus tenuicollis (C. tenuicollis) of Taenia hydatigena (T. hydatigena) from livestock isolates in Egypt, and to introduce a detailed image of C. tenuicollis infection in ruminant animals in Upper Egypt. MethodsThe prevalence rates of C. tenuicollis infections among the slaughtered animals from different organs were determined using the amplification of sequencing of the MT-CO1 gene. ResultsIn the present study the infection rates of C. tenuicollis were found to be 16% and 19% in sheep and goat samples respectively. Firstly we report one larval stage of T. hydatigena detected in the camel liver in Egypt. C. tenuicollis infection manifested a higher prevalence in females than in males. Those above two years of age manifested a higher infection rate than younger animals. The preferred site for the infection was the omentum: a 70% preference in sheep and a 68% preference in goats. The molecular characterization using the MT-CO1 gene of isolates from sheep, goats and camels corresponded to T. hydatigena. For this study, molecular characterizations of T. hydatigena were done for the first time in Egypt. Molecular tools are of great assistance in characterizing the C. tenuicollis parasite especially when the morphological character cannot be detected, because the metacestodes are frequently confused with infection by the hydatid cyst, especially when these occur in the visceral organs. In the present study, C. tenuicollis manifested high identity in the goat and sheep samples, while differences were found more frequently in the camel samples (10 base pair). ConclusionsClearly molecular diagnosis for C. tenuicollis infection significantly helps to differentiate it from such other metacestodes as hydatidosis, which manifests a completely different pathogenicity and requires different control programs.

Benign mesenchymal hepatic tumors in camels (Camelus dromedarius)

Benign tumors in liver are rare and appear not to have been previously reported in camel (Camelus dromedarius). This study describes histopathologic characteristics of lipoma, cavernous hemangioma and leiomyoma in the liver of dromedary camels. Seventy livers of dromedary camels which were slaughtered for human consumption were collected from July to November 2011 from the north east of Iran and they had macroscopic lesions and all of them were studied histopathologically. Microscopic examination revealed different metaplastic and neoplastic lesions in the liver of the camels. Lipoma (with multiple large vacuolated cells), cavernous hemangioma (with large lakes filled with oval erythrocytes) and leiomyoma (with homogenous intense eosinophilic spindle cells) were diagnosed as benign tumors. The relatively high occurrence of these mesenchymal neoplastic lesions may be due to some metabolic imbalances and some toxicosis in dromedary camels which live in the deserts. Also, metaplastic changes are the causes of lipoma. According to the literature, this is the first report of hepatic cavernous hemangioma and leiomyoma in camels (Camelus dromedarius).

Human Health Risk of Dietary Intake of Some Organochlorine Pesticide Residues in Camels Slaughtered in the Districts of Al-Qassim Region, Saudi Arabia.

Organochlorine residues were detected in 54/200 of muscles and 55/200 of livers of camels slaughtered in different districts of Al-Qassim region, Saudi Arabia, by using GC/MS analysis. The ΣDDT residues (Σ-DDT=p,p'-DDT+p,p'-DDE+p,p'-DDD+p,p'-DDA) in muscles and livers were the most frequent. The levels and distribution of residues varied with location. Al-Qassim region population's average estimated daily intake (EDI) was between 0.0 and 12.74 μg/kg body weight/day, and the hazard index [EDI/acceptable daily intake (ADI)] was higher than unity for ΣDDT and lindane in some samples. The intakes were much higher than the ADIs in some districts of Al-Qassim region, and the exposure level of all tested residues was high enough to produce health risk, suggesting the need for regular monitoring programs for pesticide residues in camel meat at the national level to protect consumers' health.

Copper-Induced Inactivation of Camel Liver Glutathione S-Transferase.

Glutathione S-transferases (GSTs) are multifunctional enzymes and play an important role in detoxification of xenobiotics and protection against oxidative stress. Camel liver glutathione transferase (cGST) was recently isolated and characterized in our lab. In this study, we have evaluated the effect of monovalent, divalent, and trivalent cations on its activity and stability. Cu(++) was found to be the potent inhibitor of GST activity which loses complete activity at 0.5-mM concentration. Other metal ions did not inhibit GST even at higher concentration of 2 mM. GST incubated with Cu(++) (0.1 mM) resulted decrease in free sulfhydryl groups by 55%, whereas other metal ions did not show any effect on free thiol content. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed formation of GST aggregates instantly in the presence of Cu(++), which further increased in molecular size with increase in time of incubation. DTT treatment resulted in de-aggregation of GST oligomers to its monomeric form. However, the GST activity was not recovered completely after de-aggregation. Cu(++) was found to inhibit GST activity by accelerating the inter- and intra-disulfide bond formation. Far-UV circular dichroism (CD) results showed that Cu(++)-catalyzed air oxidation of sulfhydryl groups leads to minor conformational changes in the GST.

Effect of Aflatoxin B1 (AFB1) Residues on the Pathology of Camel Liver

Effect of Aflatoxin B1 (AFB1) Residues on the Pathology of Camel Liver

Aerobic Bacteria Isolated from Condemned Camel Livers in Southern Darfur, Sudan

The objective of this study was to estimate the magnitude of liver condamnination due to bacterial infection and to characterize aerobic bacteria causing camel liver condamnination in Nyala city, South Darfur, Sudan. Eight hundred and ten camel livers were inspected and one hundred and three liver samples were collected in 2008-2010. Bacteriological and serological methods were used to isolate and identify aerobic bacteria causing liver infection. Results showed that the bacterial lesions were found in 36 (35%) samples out of 103 condemned inspected camel livers, the others causes were hydatid cyst 37 (35.9%), fibrosis 26 (25.2%) and calcification 4 (3.9%). Bacterial lesions consist of: abscesses 22 (61.1%), caseated nodules 13 (36.1%) and one (2.8%) congestion. Out of 36 aerobically incubated samples, 29 showed bacterial growth (80.6%) and seven cultures (19.4%) showed no growth. The isolates were identified to Staphylococcus spp. 11 (37.9%) which included; Staphylococcus aureus (S. aureus) 7 (63.6%), S. haemolyticus 3 (27.3%) and one (9.1%) S. caseolyticus while, Streptococcus pyogenes was found to be nine (31.0%) and Corynebactriumpseudotuberclosissix (20.7%). Mixed cultures (Staphylococcus and Streptococcus) were found to be three (10.3%). Many bacteria seem to be caused camel liver condamnination and the most one is S. aureustherefore, camel liver need carefully inspection and awareness about consumption of raw livermust be raise

Optimization of Storage and Stability of Camel Liver Glutathione S-Transferase

Glutathione S-transferases (GSTs) are multifunctional enzymes and play an important role in cellular detoxification. Besides this, GSTs act as cytosolic carrier proteins that bind hydrophobic compounds such as heme, bilirubin, steroids, and polycyclic hydrocarbons. GST has great importance in biotechnology, as it is a target for vaccine and drug development and biosensors development for xenobiotics. Moreover, the GST tag has been extensively used for protein expression and purification. Until now, biophysical properties of camel liver GST have not been characterized. In the present study we have purified camel (Camelus dromedarius) liver GST to homogeneity in a single step by affinity chromatography with 23.4-fold purification and 60.6% yield. Our results showed that maximal activity of GST was at pH 6.5 and it was stable in the pH range of 5 to 10. The optimum temperature was 55°C and the Tm was 57°C. The chemical chaperone glycerol (3.3 M) was able to protect GST activity and aggregation against thermal denaturation by stabilizing the protein structure at 50 and 57°C, respectively. However, L-arginine (125 mM) did not protect GST against thermal stress. Far-ultraviolet circular dichroism (CD) spectra showed that glycerol protected the secondary structure of GST while L-arginine induced conformational changes under thermal stress. In conclusion, our studies on the GST stability suggest that glycerol works as a stabilizer and L-arginine acts as a destabilizer.

Danofloxacin and Marbofloxacin Activity on Some Bacterial Isolates from Camels (Camelus dromedarius)

Bacterial diseases in camel cause morbidity, mortality, suffering and significant economic losses. This study assessed the types of bacteria involved in different types of lesions encountered in camel's lung and liver slaughtered at municipal slaughter houses of Rabat, Morocco. Bacterial species isolated and identified included Staphylococcus aureus (19.2%), Staphylococcus sp (46.1%), Streptococcus sp (7.6%), Corynebacterium sp (15.3%) and Acinetobacter sp (11.5%). The percentage of resistance of isolates to the antibiotics varied from 0 to 84.6%. The most frequent resistance was to Ampicillin and Penicillin G (84.6%) followed by Gentamycin and Tetracycline (11.5. %), while all the isolates were susceptible to Cephalothin and Ciprofloxacin. Minimum inhibitory concentrations (MIC) of danofloxacin and marbofloxacin were determined against these bacteria. Time-kill curves against staphylococcus aureus (MIC=0.25μg/ml), Streptococcus sp (MIC=0.5μg/ml), Corynebacterium sp (MIC=0.5μg/ml) for both danofloxacin and marbofloxacin, and Acinetobacter sp (MIC=0.125μg/ml for marbofloxacin and 0.25 μg/ml for danofloxacin) were then determined according to a broth microdilution test. The pharmacodynamic parameters as lowest effective concentration (LEC) and optimal bactericidal concentration (OBC) were determined. Optimal values of surrogate markers predicting the antimicrobial effect and preventing the development of resistance were widely reached.

Purification and characterization of glucose-6-phosphate dehydrogenase from camel liver.

Glucose-6-phosphate dehydrogenase from camel liver was purified to homogeneity by ammonium sulfate precipitation and a combination of DEAE-cellulose, Sephacryl S-300 gel filtration, and 2′, 5′ ADP Sepharose 4B affinity chromatography columns. The specific activity of camel liver G6PD is increased to 1.80438 units/mg proteins with 63-fold purification. It turned out to be homogenous on both native PAGE and 12% SDS PAGE, with a molecular weight of 64 kDa. The molecular weight of the native form of camel liver G6PD was determined to be 194 kDa by gel filtration indicating a trimeric protein. The K m value was found to be 0.081 mM of NADP+. Camel liver G6PD displayed its optimum activity at pH 7.8 with an isoelectric point (pI) of pH 6.6–6.8. The divalent cations MgCl2, MnCl2, and CoCl2 act as activators; on the other hand, CaCl2 and NiCl2 act as moderate inhibitors, while FeCl2, CuCl2, and ZnCl2 are potent inhibitors of camel liver G6PD activity. NADPH inhibited camel liver G6PD competitively with K i value of 0.035 mM. One binding site was deduced for NADPH on the enzyme molecule. This study presents a simple and reproducible purification procedure of G6PD from the camel liver.

Genomics, phylogeny and in silico analysis of mitochondrial glutathione S-transferase-kappa from the camel Camelus dromedarius

The domesticated one-humped camel, Camelus dromedarius, is one of the most important animals in the Arabian Peninsula. For most of its life, this species is exposed to both intrinsic and extrinsic genotoxic factors that cause gross DNA alterations in many organisms. GST enzymes constitute an important supergene family involved in protection against the deleterious effects of oxidative stress and xenobiotics. Cloning the camel mitochondrial GST kappa (GSTK) gene and comparing its structural similarities with different species may aid in understanding its evolutionary relics. We cloned the camel GSTK using RT-PCR. This yielded an open reading frame of 678 nucleotides, encoding a protein of 226 amino acid residues. In a comparative analysis, the cloned GSTK was used to screen orthologues from different organisms. Phylogenetic analysis demonstrated that the camel GSTK apparently evolved from an ancestral GSTK gene that predated the appearance of vertebrates, and it grouped with pig, cattle, dog, horse, human and monkey GSTKs. The calculated molecular weight of the translated ORF was 25.52 kDa and the isoelectric point was 8.4. The deduced cGSTK sequence exhibited high identity with many mammals, such as Bactrian camel (99.55%), pig, cattle and human (>74%), and lower identity with other unrelated organisms, such as frog (Xenopus tropicalis, 61%), chicken (Gallus gallus, 57%), salmon (Salmo salar, 49%), sponge (Amphimedon queenslandica, 46%), tick (Amblyomma maculatum, 45%) and roundworm (Caenorhabditis elegans, 33%). A 3D structure was built based on the crystal structure of the human and rat enzymes. The levels of cGSTK expression in five camel tissues were examined via real-time PCR. The highest level of cGSTK transcripts was found in the camel liver, followed by the testis, spleen, kidney and lung.