Exploration of antimicrobial and anticancer activities of L-amino acid oxidase from Egyptian Naja haje venom

Hepatocellular carcinoma and bacterial resistance are major health burdens nowadays. Thus, providing new therapies that overcome that resistance is of great interest, particularly those derived from nature rather than chemotherapeutics to avoid cytotoxicity on normal cells. Venomous animals are among the natural sources that assisted in the discovery of novel therapeutic regimens. L-amino acid oxidase Nh-LAAO (140 kDa), purified from Egyptian Naja haje venom by a successive two-step chromatography protocol, has an optimal pH and temperature of 8 and 37 °C. Under standard assay conditions, Nh-LAAO exhibited the highest specificity toward L-Arg, L-Met and L-Leu, with Km and Vmax values of 3.5 mM and 10.4 μmol/min/ml, respectively. Among the metal ions, Ca+2, Na+, and K+ ions are activators, whereas Fe+2 inhibited LAAO activity. PMSF and EDTA slightly inhibited the Nh-LAAO activity. In addition, Nh-LAAO showed antibacterial and antifungal activities, particularly against Gentamicin-resistant P. aeruginosa and E. coli strains with MIC of 18 ± 2 μg/ml, as well as F. proliferatum and A. parasiticus among the selected human pathogenic strains. Furthermore, Nh-LAAO exhibited anti-proliferative activity against cancer HepG2 and Huh7 cells with IC50 of 79.37 and 60.11 μg/ml, respectively, with no detectable effect on normal WI-38 cells. Consequently, the apoptosis % of the HepG2 and Huh7 cells were 12 ± 1 and 34.5 ± 2.5 %, respectively, upon Nh-LAAO treatment. Further, the Nh-LAAO arrested the HepG2 and Huh7 cell cycles in the G0/G1 phase. Thus, the powerful selective cytotoxicity of L-amino acid oxidase opens up the possibility as a good candidate for clinical cancer therapy.

Cloning and catalytic profile of Hyalomma dromedarii leucine aminopeptidase

Ticks have harmful impacts on both human and animal health and cause considerable economic losses. Leucine aminopeptidase enzymes (LAP) play important roles during tick infestation to liberate vital amino acids necessary for growth. The aim of the current study is to identify, express and characterize the LAP from the hard tick Hyalomma dromedarii and elucidate its biochemical characteristics. We cloned an open reading frame of 1560 bp encoding a protein of 519 amino acids. The LAP full-length was expressed in Escherichia coli BL21 (DE3) and purified. The recombinant enzyme (H.d rLAP- 6×His) had a predicted molecular mass of approximately 55 kDa. Purification and the enzymatic characteristics of H.d rLAP- 6×His were studied. The purified enzyme showed maximum activity at 37 °C and pH 8.0-8.5 using Leu-p-nitroanilide as a substrate. The activity of H.d rLAP- 6×His was sensitive to β-mercaptoethanol, dl-dithiothreitol, 1,10- phenanthroline, bestatin HCl, and EDTA and completely abolished by 0.05 % SDS. In parallel, the enzymatic activity was enhanced by Ni2+, Mn2+ and Mg2+, partially inhibited by Na+, Cu2+, Ca2+ and completely inhibited by Zn2+.

Altering Escherichia coli envelope integrity by mimicking the lipoprotein RcsF

Escherichia coli cell envelope is crucial for stress sensing and signal transduction, mediated by numerous protein-protein interactions to enable adaptation and survival. Interfering with these interactions might affect envelope integrity leading to bacterial death. The outer membrane lipoprotein (RcsF) is the stress sensor of the regulator of capsule synthesis (Rcs) phosphorelay that senses envelope threats. RcsF interacts with two essential proteins, IgaA (repressing the Rcs system) and BamA (inserting β-barrel proteins in the outer membrane). Disturbing RcsF interactions may alter Rcs signaling and/or membrane integrity thus affecting bacterial survival. Here, we derived the sequence of a peptide mimicking RcsF (RcsFmim), based on the in silico docking of RcsF with IgaA. Expression of rcsFmim caused 3-to-4-fold activation of the Rcs system and perturbation of the outer membrane. Both effects result in decreased E. coli growth rate. We anticipate that RcsFmim present a candidate for future antibacterial peptide development.

Biomarkers for Hepatocellular Carcinoma: From Origin to Clinical Diagnosis

The incidence of hepatocellular carcinoma (HCC) and HCC-related deaths has increased over the last few decades. There are several risk factors of HCC such as viral hepatitis (B, C), cirrhosis, tobacco and alcohol use, aflatoxin-contaminated food, pesticides, diabetes, obesity, nonalcoholic fatty liver disease (NAFLD), and metabolic and genetic diseases. Diagnosis of HCC is based on different methods such as imaging ultrasonography (US), multiphasic enhanced computed tomography (CT), magnetic resonance imaging (MRI), and several diagnostic biomarkers. In this review, we examine the epidemiology of HCC worldwide and in Egypt as well as risk factors associated with the development of HCC and, finally, provide the updated diagnostic biomarkers for the diagnosis of HCC, particularly in the early stages of HCC. Several biomarkers are considered to diagnose HCC, including downregulated or upregulated protein markers secreted during HCC development, circulating nucleic acids or cells, metabolites, and the promising, recently identified biomarkers based on quantitative proteomics through the isobaric tags for relative and absolute quantitation (iTRAQ). In addition, a diagnostic model used to improve the sensitivity of combined biomarkers for the diagnosis of early HCC is discussed.

The first detection of SARS-CoV-2 RNA in urban wastewater in Giza, Egypt

The new coronavirus (SARS-CoV-2) is a respiratory virus causing coronavirus disease (COVID-19). Individuals with COVID-19 can shed the viral genome in their feces, even if they do not have symptoms, and the virus can be detected in wastewater. The current study provides the first surveillance of SARS-CoV-2 RNA genome in the wastewater in Egypt. To study this aim, untreated influent (n = 48) and treated effluent (n = 48) samples were collected between January and December 2021 from the wastewater treatment plant in Giza. The viral RNA genome was determined by reverse transcription-polymerase chain reaction (RT-PCR) (S, E, and N target regions) and real-time quantitative reverse transcription-PCR (RT-qPCR) (N1 and N2 target regions). The RT-PCR assay failed to detect SARS-CoV-2 RNA in all samples analyzed, whereas RT-qPCR succeeded in the detection of N gene of SARS-CoV-2 in 62.5% of untreated influent samples. The RT-qPCR Ct values of those samples tested positive ranged from 19.9 to 30.1 with a mean of 23. The treated effluent samples were negative for viral RNA detected by both RT-PCR and RT-qPCR, indicating the efficiency of the sewage treatment plant in degrading SARS-CoV-2. Our preliminary findings provide evidence for the value of wastewater epidemiology approach for the surveillance of SARS-CoV-2 in the population to assist in the responses of public health to COVID-19 outbreak.

Egyptian cobra (Naja haje haje) venom phospholipase A2: a promising antiviral agent with potent virucidal activity against simian rotavirus and bovine coronavirus

Viral infections are linked to a variety of human diseases. Despite the achievements made in drug and vaccine development, several viruses still lack preventive vaccines and efficient antiviral compounds. Thus, developing novel antiviral agents is of great concern, particularly the natural products that are promising candidates for such discoveries. In this study, we have purified an approximately 15 kDa basic phospholipase A2 (PLA2) enzyme from the Egyptian cobra Naja haje haje venom. The purified N. haje PLA2 showed a specific activity of 22 units/mg protein against 6 units/mg protein for the whole crude venom with 3.67-fold purification. The antiviral activity of purified N. haje PLA2 has been investigated in vitro against bovine coronavirus (BCoV) and simian rotavirus (RV SA-11). Our results showed that the CC50 of PLA2 were 33.6 and 29 µg/ml against MDBK and MA104 cell lines, respectively. Antiviral analysis of N. haje PLA2 showed an inhibition of BCoV and RV SA-11 infections with a therapeutic index equal to 33.6 and 16, respectively. Moreover, N. haje PLA2 decreased the BCoV and RV SA-11 titers by 4.25 log10 TCID50 and 2.5 log10 TCID50, respectively. Thus, this research suggests the potential antiviral activity of purified N. haje PLA2 against BCoV and RV SA-11 infections in vitro.

Epoxy functionalized iron oxide magnetic nanoparticles for catalase enzyme covalent immobilization

An aqueous solution of magnetite (Fe3O4) nanoparticles was synthesized using the method of co-precipitation. The nanoparticles were activated with epichlorohydrin for covalently immobilizing the catalase enzyme. The immobilization conditions were optimized as 0.07 mg/ml catalase for 1 h contact time. The properties of free and immobilized catalase were also investigated. The immobilized enzyme showed enhanced activity at alkaline pH and retained about 90% of its relative activity between pH (6–8) and resisted the high temperature and retained 90% of its relative activity at 50 °C. Kinetic parameters of free and immobilized catalase were investigated. While the Vmax value of the immobilized enzyme was reduced 2.4 fold compared to the free enzyme, the KM value of the immobilized catalase was higher by 2.2 fold than the free enzyme. The formulated matrix enhanced the velocity of the immobilized catalase more than the free one and was able to be used for about 18 cycles with retention of 80% of its activity. The immobilized catalase on epoxy functionalized iron oxide nanoparticles is promising as a nano-bio-catalyst carrying out in many industries and different fields.

Assessment of specific human antibodies against SARS-CoV-2 receptor binding domain by rapid in-house ELISA

BACKGROUND

The recently emerged SARS-CoV-2 caused a global pandemic since the last two years. The urgent need to control the spread of the virus and rapid application of the suitable health measures raised the importance of available, rapid, and accurate diagnostic approaches.

OBJECTIVE

The purpose of this study is to describe a rapid in-house optimized ELISA based on the expression of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein in a prokaryotic system.

METHODS

We show the expression of the 30 kDa recombinant SARS-CoV-2 RBD-6×His in four different E. coli strains (at 28∘C using 0.25mM IPTG) including the expression strain E. coli BL21 (DE3) Rosetta Gami. SARS-CoV-2 rRBD-6×His protein was purified, refolded, and used as an antigen coat to assess antibody response in human sera against SARS-CoV-2 infection.

RESULTS

The assessment was carried out using a total of 155 human sero-positive and negative SARS-CoV-2 antibodies. The ELISA showed 69.5% sensitivity, 88% specificity, 78.5% agreement, a positive predictive value (PPV) of 92.3%, and a negative predictive value of 56.5%. Moreover, the optical density (OD) values of positive samples significantly correlated with the commercial kit titers.

CONCLUSIONS

Specific human antibodies against SARS-CoV-2 spike protein were detected by rapid in-house ELISA in sera of human COVID-19-infected patients. The availability of this in-house ELISA protocol would be valuable for various diagnostic and epidemiological applications, particularly in developing countries. Future studies are planned for the use of the generated SARS-CoV-2 rRBD-6×His protein in vaccine development and other diagnostic applications.

Grafted carrageenan: alginate gel beads for catalase enzyme covalent immobilization

A new matrix formulation was devised for catalase immobilization. Carrageenan-alginate beads different ratios were developed and soaked into different ratios of CaCl₂-KCl as a hardening solution. The best formulation for loading capacity was selected, treated with polyethylene imine followed by glutaraldehyde and further studied. The best concentration of catalase for immobilization was 300U/ml and the best loading time was 6 h. The catalytic properties increased after immobilization and the immobilized catalase achieved optimum activity at a temperature range of 30-50 °C that was compared to the optimum activity of free catalase which occurred at 40 °C. Higher catalytic activity of immobilized catalase occurred at alkaline pHs than the free one which achieved optimum catalytic activity at neutral pH. A comparison between the kinetic parameters of immobilized and free catalase showed variation. The K _M and Vmax of the immobilized catalase were 2.4 fold and six times higher than those of free catalase. The results of the study indicate that the formulated matrix can be used as a good matrix for catalase enzyme in various industrial applications.

A review of monoclonal antibodies in COVID-19: Role in immunotherapy, vaccine development and viral detection

The harmful COVID-19 pandemic caused by the SARS-CoV-2 coronavirus imposes the scientific community to develop or find conventional curative drugs, protective vaccines, or passive immune strategies rapidly and efficiently. Passive immunity is based on recovering hyper-immune plasma from convalescent patients, or monoclonal antibodies with elevated titer of neutralizing antibodies with high antiviral activity, that have potential for both treatment and prevention. In this review, we focused on researching the potentiality of monoclonal antibodies for the prevention and treatment of COVID-19 infection. Our research review includes antibody-based immunotherapy, using human monoclonal antibodies targeting SARS-CoV-2 viral protein regions, specifically the spike protein regions, and using hyper-immune plasma from convalescent COVID-19 patients, in which monoclonal antibodies act as immunotherapy for the cytokine storm syndrome associated with the COVID-19 infection. In addition, we will demonstrate the role of the monoclonal antibodies in the development of candidate vaccines for SARS-CoV-2. Moreover, the recent progress of the diagnostic mouse monoclonal antibodies' role will be highlighted, as an accurate and rapid diagnostic assay, in the antigen detection of SARS-CoV-2. In brief, the monoclonal antibodies are the potential counter measures that may control SARS-CoV-2, which causes COVID-19 disease, through immunotherapy and vaccine development, as well as viral detection.

A review of monoclonal antibodies in COVID-19: Role in immunotherapy, vaccine development and viral detection

The harmful COVID-19 pandemic caused by the SARS-CoV-2 coronavirus imposes the scientific community to develop or find conventional curative drugs, protective vaccines, or passive immune strategies rapidly and efficiently. Passive immunity is based on recovering hyper-immune plasma from convalescent patients, or monoclonal antibodies with elevated titer of neutralizing antibodies with high antiviral activity, that have potential for both treatment and prevention. In this review, we focused on researching the potentiality of monoclonal antibodies for the prevention and treatment of COVID-19 infection. Our research review includes antibody-based immunotherapy, using human monoclonal antibodies targeting SARS-CoV-2 viral protein regions, specifically the spike protein regions, and using hyper-immune plasma from convalescent COVID-19 patients, in which monoclonal antibodies act as immunotherapy for the cytokine storm syndrome associated with the COVID-19 infection. In addition, we will demonstrate the role of the monoclonal antibodies in the development of candidate vaccines for SARS-CoV-2. Moreover, the recent progress of the diagnostic mouse monoclonal antibodies' role will be highlighted, as an accurate and rapid diagnostic assay, in the antigen detection of SARS-CoV-2. In brief, the monoclonal antibodies are the potential counter measures that may control SARS-CoV-2, which causes COVID-19 disease, through immunotherapy and vaccine development, as well as viral detection.

Mechanisms of protein aggregation and inhibition

Protein and peptide aggregation raises keen interest due to their involvement in number of pathological conditions ranging from neurodegenerative disorders to systemic amyloidosis. Here, we have reviewed recent advances in mechanisms of aggregation, emerging technologies towards exploration, characterization of aggregate structures, detection at molecular level and the strategies to combat the phenomenon of aggregation both in cellular and in vitro conditions. In consistence, we have illustrated almost all factors that influence the protein aggregation both in vitro and in vivo environments. In addition, we have discussed a detailed journey of protein aggregation phenomenon that starts with very first events of protein aggregation. We had also described advancement in current scenarios, present aspects of fibril association to several life threatening disorders and current experimental strategies that are employed to oppose or reverse the amyloid formation.

Interaction of anticancer drug clofarabine with human serum albumin and human α-1 acid glycoprotein. Spectroscopic and molecular docking approach

The binding interaction between clofarabine, an important anticancer drug and two important carrier proteins found abundantly in human plasma, Human Serum Albumin (HSA) and α-1 acid glycoprotein (AAG) was investigated by spectroscopic and molecular modeling methods. The results obtained from fluorescence quenching experiments demonstrated that the fluorescence intensity of HSA and AAG is quenched by clofarabine and the static mode of fluorescence quenching is operative. UV-vis spectroscopy deciphered the formation of ground state complex between anticancer drug and the two studied proteins. Clofarabine was found to bind at 298K with both AAG and HSA with the binding constant of 8.128×10³ and 4.120×10³ for AAG and HSA, respectively. There is stronger interaction of clofarabine with AAG as compared to HSA. The Gibbs free energy change was found to be negative for the interaction of clofarabine with AAG and HSA indicating that the binding process is spontaneous. Binding of clofarabine with HSA and AAG induced ordered structures in both proteins and lead to molecular compaction. Clofarabine binds to HSA near to drug site II. Hydrogen bonding and hydrophobic interactions were the main bonding forces between HSA-clofarabine and AAG-clofarabine as revealed by docking results. This study suggests the importance of binding of anticancer drug to AAG spatially in the diseases like cancers where the plasma concentration of AAG increases many folds. Design of drug dosage can be adjusted accordingly to achieve optimal treatment outcome.

Inhibition of the recombinant cattle tick Rhipicephalus (Boophilus) annulatus glutathione S-transferase

Rhipicephalus (Boophilus) annulatus is a bloodsucking ectoparasite that causes severe production losses in the cattle industry. This study aims to evaluate the in vitro effects of tannic acid, hematin (GST inhibitors) and different plant extracts (rich in tannic acid) on the activity of the recombinant glutathione S-transferase enzyme of the Egyptian cattle tick R. annulatus (rRaGST), in order to confirm their ability to inhibit the parasitic essential detoxification enzyme glutathione S-transferase. Extraction with 70% ethanol of Hibiscus cannabinus (kenaf flowers), Punica granatum (red and white pomegranate peel), Musa acuminata (banana peel) (Musaceae), Medicago sativa (alfalfa seeds), Tamarindus indicus (seed) and Cuminum cyminum (cumin seed) were used to assess: (i) inhibitory capacities of rRaGST and (ii) their phenolic and flavonoid contents. Ethanol extraction of red pomegranate peel contained the highest content of phenolic compounds (29.95mg gallic acid/g dry tissue) compared to the other studied plant extracts. The highest inhibition activities of rRaGST were obtained with kenaf and red pomegranate peel (P. granatum) extracts with IC50 values of 0.123 and 0.136mg dry tissue/ml, respectively. Tannic acid was the more effective inhibitor of rRaGST with an IC50 value equal to 4.57μM compared to delphinidine-HCl (IC50=14.9±3.1μM). Gossypol had a weak inhibitory effect (IC50=43.7μM), and caffeic acid had almost no effect on tick GST activity. The IC50 values qualify ethacrynic acid as a potent inhibitor of rRaGST activity (IC50=0.034μM). Cibacron blue and hematin showed a considerable inhibition effect on rRaGST activity, and their IC50 values were 0.13μM and 7.5μM, respectively. The activity of rRaGST was highest for CDNB (30.2μmol/min/mg protein). The enzyme had also a peroxidatic activity (the specific activity equals 26.5μmol/min/mg protein). Both tannic acid and hematin inhibited rRaGST activity non-competitively with respect to GSH and competitively with respect to CDNB. While red pomegranate extracts inhibited rRaGST activity competitively with respect to GSH, uncompetitive inhibition was observed with respect to CDNB.

Curcumin protection activities against γ-rays-induced molecular and biochemical lesions

Background

Curcumin is a yellow-pigment phenolic compound used as a food spice and has a broad spectrum of antioxidant, anti-carcinogenic, anti-mutagenic and anti-inflammatory properties.

Methods

Radio-protective efficacy of curcumin; diferuloylmethane (C₂₁H₂₀O₆) was evaluated using molecular and biochemical assays in male mice after exposure to 3 Gy γ-rays. Curcumin was given at a dose of 400 μmol/ kg body weight via gastric tubes for 5 following days either pre-, post- or both pre- and post-exposure.

Results

The incidence of aberrant cells and aberration types (mostly chromatids, breaks and fragments) was reduced with curcumin dosage as compared to irradiated group. Thiobarbituric acid reactive substances (TBARS), hydroperoxide (HP), xanthine oxidase (XO) and apoptotic markers (DNA- fragmentation and caspase-3 activation) were increased significantly, whereas levels of glutathione (GSH) and the enzymatic antioxidants [Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)] were significantly depleted in γ-irradiated mice. Curcumin treatments of mice groups including the 5 days pre-irradiation treated group (protected), the 5 days post-irradiation treated group (treated), and the curcumin treated group 5 days pre- and post-irradiation (protracted), have attenuated the liver toxic effects of γ-rays as manifested by reducing the levels of TBARS, HP, XO and DNA fragmentation. Curcumin has also rescued the depletion of GSH and the enzymatic-antioxidant status.

Conclusions

Curcumin has significant radio-protective and radio-recovery activities in γ-irradiated mice. It has antioxidant potential against γ-rays-induced cytogenetic, molecular and biochemical lesions in mice.

Evaluation of glycoproteins purified from adult and larval camel ticks (Hyalomma dromedarii) as a candidate vaccine

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 µg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.

Purification and characterization of a cytotoxic neurotoxin-like protein from Naja haje haje venom that induces mitochondrial apoptosis pathway

This study reported the purification and characterization of a cytotoxic, neurotoxin-like protein derived from the venom of the Egyptian cobra Naja haje haje, Elapidae family, and explored their mechanistic role in the cell death. The protein purification was performed through ion-exchange chromatography and gel-filtration chromatography and was characterized by SDS-PAGE, amino acid sequencing, and mass spectrum analysis. The antitumor activity of Naja haje venom (NHV) and its fractions (NHVI, NHV-Ia, NHV-Ib, NHV-Ic, NHV-II, NHV-III, and NHV-IV) were tested against different human cancer cell lines. The molecular cascade of cell death was explored through evaluation of apoptosis/necrosis ratio, DNA fragmentation, histone deacetylase (HDAC) activity, mitochondrial transmembrane potential (Δψ(m)), cytochrome c release, total caspases, caspase-3, caspase-9, and cell cycle analysis by flow cytometry. Most of the separated fractions possessed variable cytotoxic effect against different cancer cells. The most potent antitumor fraction was NHV-Ic due to its ability to induce DNA damaging and fragmentation that was associated with a significant induction of apoptosis via mitochondrial pathway and disturbed cell cycle phases as well as an inhibition of HDAC activity. NHV-Ic induced the mitochondrial pathway initially by the impairment of Δψ(m) besides the DNA damage and in response to that the mitochondria-released cytochrome c that may in turn activated total caspases, caspase-3 and caspase-9 in lymphoblastic leukemia 1301 cells. The partial amino acid sequencing of NHV-Ic revealed 100, 95.65, and 91.3% homology with the Long neurotoxin 1 from Naja haje anchietae (Angolan cobra), Naja haje haje (Egyptian cobra), and Boulengerina annulata annulata (banded water cobra), respectively.

Phytotherapeutic effects of Echinacea purpurea in gamma-irradiated mice

Echinacea (E.) purpurea herb is commonly known as the purple coneflower, red sunflower and rudbeckia. In this paper, we report the curative efficacy of an Echinacea extract in γ-irradiated mice. E. purpurea was given to male mice that were divided into five groups (control, treated, irradiated, treated before irradiation & treated after irradiation) at a dose of 30 mg/kg body weight for 2 weeks before and after irradiation with 3 Gy of γ-rays. The results reflected the detrimental reduction effects of γ-rays on peripheral blood hemoglobin and the levels of red blood cells, differential white blood cells, and bone marrow cells. The thiobarbituric acid-reactive substances (TBARs) level, Superoxide dismutase (SOD) and glutathione peroxidase (GSPx) activities and DNA fragmentation were also investigated. FT-Raman spectroscopy was used to explore the structural changes in liver tissues. Significant changes were observed in the microenvironment of the major constituents, including tyrosine and protein secondary structures. E. purpurea administration significantly ameliorated all estimated parameters. The radio-protection effectiveness was similar to the radio-recovery curativeness in comparison to the control group in most of the tested parameters. The radio-protection efficiency was greater than the radio-recovery in hemoglobin level during the first two weeks, in lymphoid cell count and TBARs level at the fourth week and in SOD activity during the first two weeks, as compared to the levels of these parameters in the control group.

Purification and characterization of two larval glycoproteins from the cattle tick, Boophilus annulatus

The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.