Purification, Characterization and Bioefficacy of Legume Lectins against Mustard Aphid

Background: Lectins are carbohydrate binding proteins which perform diverse roles in plants. One important role is in plant defense. These proteins hold great potential as entomotoxic proteins as a part of integrated pest management. Methods: Lectins were purified and characterized from seeds of two legumes, Glycine max-Soybean and Lens culinaris-Lentil, employing ammonium sulfate fractionation and ion exchange chromatography. Bioefficacy of the purified lectins was evaluated against mustard aphid.Result: Lectins isolated from seeds of soybean (Glycine max agglutinin GMA-I, II) and lentil (Lens culinaris agglutinin LCA-I) were purified upto 9.30 (GMA-I), 4.60 (GMA-II) and 8.70 (LCA-I) fold, respectively. Lectin characterization revealed that soybean agglutinin and lentil agglutinin were specific towards D-Galactose and D-mannose, respectively. Insect bioassay was carried out with five different concentrations (10, 20, 30, 40, 50 µg/ml) of purified lectins of soybean and lentil against mustard aphid. The lethal concentration LC50 value for GMA-I was obtained as 32.1 µg/ml with a 95% confidential interval of 18.2 to 40.5 µg/ml and that of LCA-I was 19.1 µg/ml with a 95% confidential interval of 9.3 to 26.8 µg/ml. Lentil lectin (LCA-I) with lower LC50 value, was found to be the potential candidate for integrated pest management.

Occurrence of Taenia species in pigs in slaughterhouses in Phu Tho province, northern Vietnam

Pigs act as the intermediate hosts of the zoonotic tapeworms Taenia solium and Taenia asiatica, as well as of the non-zoonotic Taenia hydatigena. In Vietnam, human taeniasis and cysticercosis have been reported throughout the country; however, data on porcine cysticercosis are scarce. Our study aimed to estimate the prevalence of Taenia spp. in slaughtered pigs in two districts in Phu Tho, a mountainous province in northern Vietnam from where neurocysticercosis patients commonly originate. The carcasses of 399 pigs from 51 small-scale abattoirs were checked for cysticerci, while tongue, liver, masseter muscles, diaphragm and heart were sliced and examined. Retrieved cysticerci underwent polymerase chain reaction–restriction fragment length polymorphism and sequencing for species confirmation. Blood was also collected to detect antibodies by lentil lectin-purified glycoprotein enzyme-linked immunoelectrotransfer blot (LLGP-EITB) and recombinant T24H antigen (rT24H)-EITB and circulating antigens by B158/B60 Ag-ELISA. In two pigs, T. asiatica cysticerci were found, confirming the presence of the parasite in pigs in Vietnam at a low prevalence (0.5%; 95% exact confidence interval (CI): 0–1.19%). Cysticerci of T. solium were found in none of the pigs, although one serum sample was positive for antibodies in both LLGP-EITB and rT24H-EITB. Furthermore, a high prevalence of T. hydatigena cysticercosis was observed (18.0%; 95% Wilson score CI: 14.6–22.1%). In more than half of the T. hydatigena-positive pigs, circulating antigens were detected by Ag-ELISA, confirming that this test cannot be used to diagnose T. solium cysticercosis in this region. Finally, Spirometra erinaceieuropaei was found in one pig liver. It is the first record of this zoonotic cestode species in pigs in Vietnam. Overall, the findings confirmed the complex epidemiology of Taenia spp. in pigs in Vietnam.

Laboratory Diagnosis of Neurocysticercosis (Taenia solium)

ABSTRACTNeurocysticercosis accounts for approximately 30% of all epilepsy cases in most developing countries. The immunodiagnosis of cysticercosis is complex and strongly influenced by the course of infection, the disease burden, the cyst location, and the immune response of the host. The main approach to immunodiagnosis should thus be to evaluate whether the serological results are consistent with the diagnosis suggested by imaging. Antibody detection is performed using lentil lectin-purified parasite antigens in an enzyme-linked immunoelectrotransfer blot format, while antigen detection uses a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Promising new assay configurations have been developed for the detection of both antibody and antigen, including assays based on synthetic or recombinant antigens that may reduce costs and improve assay reproducibility and multiplex bead-based assays that may provide simultaneous quantitative results for several target antigens or antibodies.

Pb2+ binding to lentil lectin and its influence on the protein aggregation

The Pb2+ binds through the side chain carboxylate and imidazole moieties of the lentil lectin by bringing some secondary structural changes. As a result of this the original aggregates of the simple protein disaggregates upon binding to Pb2+.

Two acid RNases from Dactylis glomerata seeds. Purification, properties and effect of polyamines and lectins on their activity

Two glycoproteidic acid RNases (RNase I and RNase II) were obtained and purified from the seeds of <em>Dactylis glomerata</em> by extraction with acetate buffer, fractionation with ammonium sulfate, ion-exchange chromatography on DEAE-cellulose, DEAE-Sphadex, affinity chromatography on Con A-Sepharose and gel filtration on Bio-Gel P60. RNase I with a specific activity of 2582 U•mg^-1 protein and an optimum pH of 4.9 and RNase II with a specific activity of 1928 U• mg^-1 protein and optimum pH of 4.6, were isolated. They lacked nuclease, phosphodi- and monoesterase activities. Both forms of the enzyme hydrolyzed pyrimidine homopolymers with a preference for poly U and exhibited a low specificity for purine homopolymers (poly G and poly A). RNase I acted with a 3-fold higher hydrolytic activity on poly C homopolymer than RNase IL The hydrolytic activity of both enzymes was inhibited by Zn⁺², Fe⁺², Cu⁺² ions when yeast RNA was the substrate. The amines spermine, spermidine and tyramine at a concentration of 0.1 mM increased the enzymatic activity of both RNases by 20 to 60% of the relative activity. The hydrolytic activity of RNases I and II was stimulated by the presence of lentil lectin (LL), soybean lectin (SBA) and potato lectin (STA), and inhibited by the presence of concanavalin A. The 20-200% stimulation and 40-60% inhibition depended on the proportion, on a weight basis, of enzyme to lectin and were reversible in the presence of receptor sugars.

Comparative analysis of the antibacterial activity of some phytolectins

The aim of this work was to analyse the comparative effects of the antibacterial properties of partially purified lectins from the seeds of Artocarpus heterophyllus (jack fruit), Canavalia ensiformis (jack bean), Lens culinaris (lentil) and Pisum sativum (pea) against the bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The lectins were isolated by partial purification using ammonium sulphate precipitation and dialysis. The antimicrobial activity was studied using agar well diffusion method. The results showed that the Jack fruit lectin had a potent anti-bacterial activity against S. aureus, B. subtilis, E. coli and P. aeruginosa whereas Pea and jack bean lectin were found to be effective bacteriostatic agents which reduced the growth of bacteria and lentil lectin showed the least antibacterial activity. A comparison of the antibacterial activity of phytolectins with conventional antibiotics namely ampicillin and tetracycline was also carried out. Studies revealed that the antibacterial activities of the conventional antibiotics are higher than that of the plant extracts at the same concentration in accordance to literature.DOI: http://dx.doi.org/10.3329/icpj.v2i2.13192 International Current Pharmaceutical Journal 2013, 2(2): 18-22

Evaluation of two Taenia solium cysticercal antigenic preparations (vesicular fluid and a glycoprotein fraction with affinity for lentil lectin) for the immunodiagnosis of neurocysticercosis by enzyme-linked immunosorbent assay (ELISA)

OBJECTIVE: To evaluate the performance of two antigenic preparations (vesicular fluid - VF and a glycoprotein fraction, LLa-Gp fraction, purified from a whole parasite extract by lentil lectin affinity chromatography) from Taenia solium cysticerci for the immunodiagnosis of neurocysticercosis. METHOD: Fifty-six cerebrospinal fluid (CSF) samples (22 from patients with neurocysticercosis and 34 from patients with other neurological disorders) and 57 serum samples (22 from patients with neurocysticercosis, 18 from patients with other infections and 17 from presumably healthy persons) were assayed for anticysticercal IgG antibodies with an enzyme-linked immunosorbent assay (ELISA). RESULTS: The VF ELISA showed 100% sensitivity and specificity in CSF and serum samples, whereas the sensitivity and specificity of the LLa-Gp ELISA were, respectively, 90.9% and 97.1%, with the CSF samples and 95.5% and 100% with serum samples. There was no significant difference in the sensitivity and specificity of the two antigenic preparations used to screen CSF and serum samples. CONCLUSION: Considering the complexity and high cost of obtaining the LLa-Gp fraction, VF could be more suitable for screening specific antibodies by ELISA in CSF and serum samples from patients with neurocysticercosis.