Construction of multi-epitope gene of periodic Brugia malayi and its expression in eukaryotic cells / 中华地方病学杂志

Objective:To construct a eukaryotic expression plasmid pcDNA3.1(+)-BmCPI502/BmGAPDH720 of periodic Brugia malayi cysteine protease inhibitor/glyceraldehyde 3-phosphate dehydrogenase (CPI502/GAPDH720) multi-epitope gene and observe its protein expression in Hela cells. Methods:Primers were designed according to the predicted gene sequences of T cell epitopes. The target gene fragment was amplified by reverse transcription (RT)-PCR using plasmid pGEM-T-CPI621 as template. The fragment was cloned into prokaryotic expression plasmid pET-28a(+) to construct prokaryotic expression plasmid pET28a(+)-BmCPI502. The BmCPI502 gene and BmGAPDH720 gene were amplified by RT-PCR, respectively. The gene fragments of pcDNA3.1(+), BmCPI502 and BmGAPDH720 were digested by double enzyme digestion and ligated with the target gene. The eukaryotic expression plasmid pcDNA3.1(+)-BmCPI502/BmGAPDH720 was constructed. The recombinant plasmid was transfected into Hela cells and verified by RT-PCR to obtain the desired target bands. The expression product was detected by sodium dodecyl sulfate polyacrylamide gelelectrophoresis (SDS-PAGE).Results:The recombinant plasmid pET28a(+)-BmCPI502 was obtained, and the 502 bp specific fragment was identified by enzyme digestion, which was in line with the expected value; the eukaryotic expression plasmid pcDNA3.1(+)-BmCPI502/BmGAPDH720 of the multi-epitope gene was successfully constructed, and the fragment size was in line with the expected value. The eukaryotic expression plasmid pcDNA3.1(+)-BmCPI502/BmGAPDH720 was transfected into Hela cells and the recombinant protein was stable expressed. SDS-PAGE analysis showed that the relative molecular weight ( Mr × 10 3) of the recombinant protein was about 50. Conclusions:The eukaryotic expression plasmid of pcDNA3.1(+)-BmCPI502/BmGAPDH720 of periodic Brugia malayi multi-epitope gene is successfully constructed, and the corresponding recombinant protein is obtained in eukaryotic cells. This study has laid a foundation for further study of the purification and biological activity of the recombinant protein.

Ultrastructural and enzymatic alterations in the ovary of Rhodnius prolixus infected with Trypanosoma rangeli

Objective: To investigate the morphological structure of ovarian follicular cells and biochemical parameters of both ovaries and fat bodies (sites of vitellogenesis) from Rhodnius (R.) prolixus infected with Trypanosoma (T.) rangeli. Methods: Adult virgin females of R. prolixus were fed upon a membrane apparatus containing heat-inactivated citrated rabbit blood and a suspension of T. rangeli epimastigotes (Macias strain). Females from the control group and all the males received parasitefree blood. Transmission electron microscopy was used to reveal the morphological aspects of ovarian follicle cells in both control and parasite-infected groups. Protein profile, proteolytic activities and Western blotting analyses were performed in either ovary or fat body samples of control and parasite-infected groups. Results: According to the ultrastructural data, T. rangeli infection elicited a degeneration process in the ovarian follicular cells of R. prolixus. Proteolytic assays indicated a reduction in the activity of aspartic peptidases in the ovary and fat body from parasite-infected group, while a significant increase in the cysteine peptidase activity was measured in both insect organs. Additionally, immunoblotting revealed that vitellogenin was overexpressed in the ovary of parasite-infected insects. Conclusions: T. rangeli infection seems to elicit an early programmed cell death in the ovarian follicle cells as well as induces the modulation on the activities of different peptidase classes in either ovaries or fat bodies and the overexpression of the vitellogenin in the ovary of R. prolixus.

Polarization of bone marrow-derived macrophages induced by recombinant Trichinella spiralis cysteine protease inhibitors in vitro / 中国血吸虫病防治杂志

Objective To investigate the regulatory role of recombinant Trichinella spiralis cysteine protease inhibitors (rTs-Cys) in induction of polarization of bone marrow-derived macrophages (BMDMs) in vitro. Methods BMDMs were captured and cultured in conditioned medium for 7 days. Then, mature BMDMs were harvested and assigned into four groups. Cells in Group A (negative control) were given 10 ng/mL IFN-γ combined with 100 ng/mL LPS, cells in Group B (positive control) were treated with IL-4 and IL-10 (at 10 ng/mL both), and cells in Group C (recombinant protein alone) were stimulated with 1 μg/mL rTs-Cys, while cells in Group D (protein co-culture) were simultaneously treated with 1 μg/mL rTs-Cys, 10 ng/mL IFN-γ and 100 ng/mL LPS. Cells and culture supernatant were collected 24 hour post-treatment, and the proportions of F4/80+, CD11b+, CD206+ and CD11c+ cells were detected by flow cytometry. The levels of interleukin IL-6 (IL-6), tumor necrosis factor-α (TNF-α), IL-10 and transforming growth factor-β (TGF-β) in the cell culture supernatant were measured by ELISA and the CD86+ and CD206+ phenotypes were identified by immunofluorescent staining. Results Flow cytometry detected no significant difference in the proportion of F4/80+ CD11b+ CD11c+ cells among the four groups (F = 46.184, P < 0.001), and a lower proportion of F4/80+ CD11b+ CD11c+ cells was seen in groups C and D than in group A (all P values < 0.001). There was a significant difference in the proportion of F4/80+ CD11b+ CD206+ cells among the four groups (F = 11.032, P < 0.001), and a greater proportion of F4/80+ CD11b+ CD206+ cells was seen in groups C and D than in group A (all P values < 0.01). Immunofluorescent staining showed higher CD206+ expression and lower CD86+ expression in groups C and D than in Group A. There were significant differences in the IL-6 and (F = 3.950, P < 0.001) and TNF-α (F = 205.827, P < 0.001) levels in the cell culture supernatants among the four groups, and significantly lower IL-6 and TNF-α levels were measured in groups C and D than in Group A (both P < 0.05). There were significant differences in the IL-10 and (F = 8.274, P < 0.001) and TGF-β (F = 13.559, P < 0.01) levels in the cell culture supernatants among the four groups, and greater IL-10 and TGF-β levels were measured in Group C than in Group A (both P values < 0.01). In addition, the TGF-β level was significantly higher in Group D than in Group A (P < 0.05); however, there was no significant difference in the IL-10 level between groups D and A (P > 0.05). Conclusion rTs-Cys may induce the polarization of BMDMs to antiinflammatory M2 macrophages in vitro and inhibit the activation of M1 macrophages.

Expression of cystatin A in esophageal squamous cell carcinoma and its clinical significance / 国际生物医学工程杂志

Objective To investigate the expression and clinical significance of cysteine protease inhibitor A(CSTA) in esophageal squamous cell carcinoma. Methods A total of 59 patients with esophageal cancer who underwent esophagectomy or endoscopic submucosal tumor dissection were enrolled. The esophageal squamous cell carcinoma and normal esophageal tissues were collected and clinical pathological data were collected. The expression of CSTA mRNA and protein in cancer tissues and normal tissues was determined by real-time quantitative fluorescent polymerase chain reaction (RTFQ-PCR) and immunohistochemistry. The expressions of CSTA and Ki-67 mRNA and protein in cancer tissues and normal tissues were determined by RTFQ-PCR and Western Blot. Results Compared with normal, the expression of CSTA mRNA and protein in esophageal squamous cell carcinoma tissues was significantly lower, and the difference was statistically significant (all P<0.05). In squamous cell carcinoma, the CSTA-positive expression is often associated with Ki-67 expression, whereas normal esophageal tissue has CSTA expression but no Ki-67 expression. Squamous cell carcinoma with CSTA-positive expression had higher tumor pT stage and tumor grade (all P<0.05). Conclusions The expression of CSTA in cancer tissues of patients with esophageal squamous cell carcinoma is significantly lower than that in normal tissues. The CSTA-positive expression in esophageal squamous cell carcinoma is related to the pT clasification and tumor grade. The CSTA test for esophageal squamous cell carcinoma can provide a basis for clinical treatment.

A cysteine protease from the latex of Ficus benjamina has in vitro anthelmintic activity against Haemonchus contortus / Atividade anti-helmíntica in vitro de uma protease cisteínica do látex de Ficus benjamina contra Haemonchus contortus

Abstract Haemonchus contortus is a gastrointestinal nematode that is responsible for high mortality rates in ruminant herds. The resistance of nematodes to synthetic anthelmintics is widespread and requires a continuous search for new bioactive molecules, such as proteins. The objective of this study was to evaluate the anthelmintic potential of a protease purified from the latex of Ficus benjamina against H. contortus . Fresh latex was collected from plants via small incisions in the green stems, the rubber was removed by centrifugation, and the latex protein extract (LPE) was obtained. After LPE fractionation with ammonium sulfate and chromatography of the fraction containing the highest proteolytic activity on CM-cellulose, a cysteine protease (FbP) was purified. FbP has a molecular mass of approximately 23.97 kDa, and its proteolytic activity was stable between pH 6.0 and pH 10 and over a broad temperature range, with optimum activity at 60 °C. FbP inhibited both the development and exsheathment of H. contortus larvae, with 50% effective concentrations of 0.26 and 0.79 mg/mL, respectively. We conclude that this cysteine protease from F. benjamina latex with anthelmintic activity against H. contortus could be a promising alternative for the development of products for use in parasite control programmes.

Resumo Haemonchus contortus é um nematoide gastrintestinal, responsável por altas taxas de mortalidade em rebanhos de pequenos ruminantes. A resistência dos nematoides aos anti-helmínticos sintéticos está generalizada e requer uma busca contínua por novos compostos bioativos, como as proteínas. O objetivo deste trabalho foi avaliar o potencial anti-helmíntico da protease purificada do látex de Ficus benjamina contra H. contortus . O látex fresco foi coletado das plantas por pequenas incisões nas hastes verdes e o extrato proteico de látex (EPL) foi obtido. Após o fracionamento do EPL com sulfato de amônio e cromatografia da fração contendo a maior atividade proteolítica da CM-Celulose, uma protease cisteínica (FbP) foi purificada. A FbP tem massa molecular de cerca de 23,97 kDa, a atividade proteolítica foi estável entre pH 6,0 e pH 10 e ao longo de uma ampla faixa de temperatura, com atividade ótima a 60 °C. A FbP inibiu tanto o desenvolvimento quanto o desembainhamento das larvas de H. contortus, com 50% de inibição nas concentrações de 0,26 e 0,79 mg/mL, respectivamente. Concluímos que esta protease cisteínica do látex de F. benjamina, com ação anti-helmíntica contra H. contortus, pode ser uma alternativa promissora para o desenvolvimento de produtos a serem utilizados em programas de controle de parasitos.

Molecular and Biochemical Properties of a Cysteine Protease of Acanthamoeba castellanii

Acanthamoeba spp. are free-living protozoa that are opportunistic pathogens for humans. Cysteine proteases of Acanthamoeba have been partially characterized, but their biochemical and functional properties are not clearly understood yet. In this study, we isolated a gene encoding cysteine protease of A. castellanii (AcCP) and its biochemical and functional properties were analyzed. Sequence analysis of AcCP suggests that this enzyme is a typical cathepsin L family cysteine protease, which shares similar structural characteristics with other cathepsin L-like enzymes. The recombinant AcCP showed enzymatic activity in acidic conditions with an optimum at pH 4.0. The recombinant enzyme effectively hydrolyzed human proteins including hemoglobin, albumin, immunoglobuins A and G, and fibronectin at acidic pH. AcCP mainly localized in lysosomal compartment and its expression was observed in both trophozoites and cysts. AcCP was also identified in cultured medium of A. castellanii. Considering to lysosomal localization, secretion or release by trophozoites and continuous expression in trophozoites and cysts, the enzyme could be a multifunctional enzyme that plays important biological functions for nutrition, development and pathogenicity of A. castellanii. These results also imply that AcCP can be a promising target for development of chemotherapeutic drug for Acanthamoeba infections.

Effect of cystatin from Schistosoma japonicum on DSS-induced ulcerative colitis in mice / 中国血吸虫病防治杂志

Objective To investigate the effect of cysteine protease inhibitor derived from S chistosoma japonicum(SjCys-tatin)on dextran sodium sulfate(DSS)-induced acute ulcerative colitis in mice.Methods Eighteen C57BL/6 mice were ran-domly divided into three groups:a control group treated with PBS(Group A),a DSS-induced-colitis group treated with PBS(Group B),and a DSS-induced-colitis group treated with SjCystatin(Group C).Colitis was induced in mice by giving 3％DSS orally for 7 days.During this period,the mice were daily injected with 10μg of SjCystatin or PBS only as a control intraperitone-ally.The mice were monitored daily for their clinical manifestations and given scores based on disease activity index(DAI).The severity of colonic inflammation was monitored by the macroscopic score and pathological change.The cytokine profile including TNF-α,IL-4,IL-6 and IL-10 in the supernatants of colon homogenate was detected by ELISA.Results Compared with Group A(0.50 ± 0.28),the DAI score increased significantly in Group B(9.30 ± 1.30)(F=86.86,P<0.01),with remarkable path-ological damages seen in colon tissues.and the levels of TNF-α and IL-6 were(321.33±67.01)and(403.58 ±180.51)pg/mL.The DAI score significantly reduced in Group C(6.67±1.57)as compared to Group B(F=86.86,P<0.01),with improve-ments in the macroscopic and microscopic pathology in mouse colon specimens.As compared to Group B,the levels of TNF-α [(188.14 ± 40.14)pg/mL] and IL-6 [(209.71 ± 48.47)pg/mL] significantly decreased(F=17.46 and 9.89,both P<0.01).Con-clusion SjCystatin has a significantly inhibitory effect for alleviating DSS-induced acute ulcerative colitis in C57BL/6 mice.

Cloning, expression and bioinformatics analysis of 27 kDa cysteine protease gene of Spirometra erinacei plerocercoid / 中国人兽共患病学报

To clone and express 27 kDa cysteine protease (CP) gene of Spirometra erinacei plerocercoid,and analyze the biology characteristics,a total of RNA was extracted from the plerocercoids and reversely transcribed into cDNA.The 27kDaCP gene was amplified by PCR and cloned into pM-19T vector for sequencing.The accurate sequence was subcloned into the expression vector pET-28a (+).The recombinant plasmid was transformed into Transetta (DE3) and the expression protein induced by IPTG.The recombinant protein was purified by Ni2 + affinity chromatography,and analyzed by SDS-PAGE and Western blotting.The 27 kDa CP gene and its expression protein were predicted and analyzed by bioinformatics analysis tools such as NCBI and ExPASy.Results showed that the ORF length of 27 kDa CP gene sequence was 1 011 bp,and the removed signal peptide sequence was 954 bp with the submission number of ANA52569 in GenBank.The whole sequence of 27 kDa CP (Mr 35 669.9,pI 5.92) was 317 amino acids conferred from cDNA,which belongs to the Peptidase_C39_like superfamily.The pET-28a (+)-27kDa-CP was expressed under the induction of IPTG.Western blotting analysis showed that the purified protein reach expectancy,and had better response with positive serum of Spirometra erinacei plerocercoid infection.In conclusion,the 27 kDa CP gene of Spirometra erinacei plerocercoid is successfully cloned and expressed and knowing coded sequences and bioinformatic.

Evaluation of diagnostic indicators in chronic renal failure / 国际检验医学杂志

Objective To evaluate the clinical values of endogenous creatinine clearance rate(Ccr) ,serum creatinine (SCr) ,urea nitrogen(Urea) ,serum cystatin C(s‐Cys‐C) ,serum retinol binding protein(s‐RBP) ,Urine total protein (u‐Pro) ,urine albumin and creatinine ratio(u‐Alb/Cr) ,urine RBP(u‐RBP) ,urine Cys‐C(u‐Cys‐C) ,u‐NAG and et al in the diagnosis of chronic renal failure (CRF) ,find suitable and effective detection combinations to increase the diagnostic accuracy of CRF .Methods SCr ,Urea ,s‐Cys‐C , s‐RBP ,u‐Pro ,u‐Alb/Cr ,u‐RBP ,u‐Cys‐C ,u‐NAG were detected respectively in 206 hospitalized patients and Ccr values were calcu‐lated at the same time .By using Excel and SPSS19 .0 softwares ,the data were analysed .Combined detections included two and four items combined detections .Results Youden index(YI) of serum Cys‐C was 0 .59 .Area under the curve in the receiver operating characteristic(ROC) of Cys‐C was 0 .872 which was the highest of all the single detection items .Combined detection of SCr and s‐Cys‐C got the highest YI (0 .60) .Combination of four items(Urea ,SCr ,s‐RBP ,s‐Cys‐C) had the highest positive predictive value (100 .00% ) .Combination of u‐RBP and u‐Cys‐C had the highest negative predictive value(100 .00% ) .Conclusion Combined detec‐tion was more favorable for CRF diagnosis .Combination detection of SCr and s‐Cys‐C was the most valuable detection for the diag‐nosis of CRF .Among single item detections ,s‐Cys‐C detection had better sensitivity and specificity ,and diagnostic efficiency than other detection items .U‐RBP and u‐Cys‐C could be used to exclude renal impairment due to its noninvasive sampling .

Characterization of proteases isolated from Kudoa septempunctata / 대한수의학회지

Proteases play important roles in parasite development and host parasite interactions. The protease of Kudoa spp. has been recognized as a key factor of severe proteolysis of fish muscle post-mortem; however, there is little information available regarding the protease of Kudoa (K.) septempunctata, which was recently identified as a cause of food poisoning in humans. The present study was conducted to isolate and characterize proteases to elucidate the type of protease contained in the parasite and determine the optimal pH for protease activity. We confirmed the cysteine protease and metalloprotease produced by K. septempunctata. While the cysteine protease showed optimal activity at pH 5 that decreased rapidly with increasing pH, the optimal activity of metalloprotease was pH 7, and it remained stable from pH 6 to pH 8. These results indicate that the pH of cysteine protease is not proper for fish muscle postmortem, and that metalloprotease can act in human intestines. Overall, the present study provides important information that improves our understanding of the role of protease physiology and the subsequent food poisoning caused by K. septempunctata.

Diagnostic Efficacy of a Recombinant Cysteine Protease of Spirometra erinacei Larvae for Serodiagnosis of Sparganosis

The mature domain of a cysteine protease of Spirometra erinacei plerocercoid larva (i.e., sparganum) was expressed in Escherichia coli, and its value as an antigen for the serodiagnosis of sparganosis was investigated. The recombinant protein (rSepCp-1) has the molecular weight of 23.4 kDa, and strongly reacted with the sparganum positive human or mice sera but not with negative sera by immunoblotting. ELISA with rSepCp-1 protein or sparganum crude antigen (SeC) was evaluated for the serodiagnosis of sparganosis using patient's sera. The sensitivity and specificity of ELISA using rSepCp-1 protein were 95.0% (19/20) and 99.1% (111/112), respectively. In contrast, the sensitivity and specificity of ELISA with SeC were 100% (20/20) and 96.4% (108/112), respectively. Moreover, in experimentally infected mice, the sensitivity and specificity of both ELISA assays were 100% for the detection of anti-sparganum IgG. It is suggested that the rSepCp-1 protein-based ELISA could provide a highly sensitive and specific assay for the diagnosis of sparganosis.

Partial Purification and Properties of a Cysteine Protease from Citrus Red Mite Panonychus citri

Several studies have reported that the citrus red mites Panonychus citri were an important allergen of citrus-cultivating farmers in Jeju Island. The aim of the present study was to purify and assess properties of a cysteine protease from the mites acting as a potentially pathogenic factor to citrus-cultivating farmers. A cysteine protease was purified using column chromatography of Mono Q anion exchanger and Superdex 200 HR gel filtration. It was estimated to be 46 kDa by gel filtration column chromatography and consisted of 2 polypeptides, at least. Cysteine protease inhibitors, such as trans poxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) and iodoacetic acid (IAA) totally inhibited the enzyme activities, whereas serine or metalloprotease inhibitors did not affect the activities. In addition, the purified enzyme degraded human IgG, collagen, and fibronectin, but not egg albumin. From these results, the cysteine protease of the mites might be involved in the pathogenesis such as tissue destruction and penetration instead of nutrient digestion.

Potential role(s) of cysteine cathepsins in cancer progression and metastasis / 동물의과학연구지

Cancer is the result of damage to the genetic system, i.e., dysfunction of the DNA repair system, resulting in dysregulated expression of various molecules, leading to cancer formation, migration, and invasion. In cancer progression, several proteases play a critical role in metastasis; however, their biological mechanism in cancer metastasis is not clearly understood. Among these proteases, cathepsins are a family of lysosomal proteases found in most animal cells. Cathepsins have an important role in protein turnover of mammalian, and are classified into 15 types based on their structure as serine (cathepsin A and G), aspartic (cathepsin D and E), and cysteine cathepsins (cathepsin B, C, F, H, K, L, O, S, V, X, and W). Cysteine cathepsins appear to accelerate the progression of human and rodent cancers, which can be a biomarker of the potency of malignancy or metastasis in mammalian. Overexpression of cyteine cathepsins causes the activation of angiogenesis promoting factor, whereas their downregulation reduces the angiogenesis of cancer progression. Under physiological conditions, cysteine cathepsins are essential in inflammation, infection, and cancer development. Activity of cysteine proteases, i.e., cathepsin B, is required for cancer progression or metastasis. Elevation of cysteine cathepsin is associated with cancer metastasis, angiogenesis, and immunity. Therefore, in this review, we suggest that cysteine cathepsin may be an anticancer target of strong clinical interest, although the exact mechanism of cathepsins in cancer metastasis is under investigation.

Cloning, sequencing of CPI gene from periodic Brugia malayi and prediction of B cell epitopes in its amino acid sequence / 中国地方病学杂志

Objective To clone and sequence the cysteine protease inhibitor gene of periodic Brugia malayi(BmCPI) and predict B-cell epitopes in amino acide sequence of BmCPI in order to provide basis for further study the expression of BmCPI and its function. Methods Total RNA was extracted from periodic Brugia malayi.A couple of specific primers were designed on the basis of known sequences of cysteine protease inhibitor gene from BmCPI. The desired gene was amplified by PCR technique from cDNA. The PCR products were purified and cloned into plasmid pGEM-T by T-A cloning method, transformed into Escherichia coli(E, coli) strain DH5α. The recombinant plasmids were screened and identified by digestion with restriction enzyme and PCR amplification. Five parameters and methods were used to predict B-cell epitopes in amino acide sequence of BmCPI. Results For RT-PCR, a specific band of around 621 bp was amplified. The same band was obtained by double restriction of recombinant plasmids or PCR using recombinant plasmid as template. The result of DNA sequencing showed that BmCPI shares 99% nucleotide sequence identity with that of published sequence. It showed that B-cell epitopes were probably at or adjacent to 23 - 32, 50 - 79 and 117 - 126 in its amino acide sequence. Conclusions pGEM-BmCPI is successfully constructed and sequenced, anticipated objective is reached and conditions is provided for further study of BmCPI expression and its function.

A 27 kDa Cysteine Protease Secreted by Newly Excysted Paragonimus westermani Metacercariae Induces Superoxide Anion Production and Degranulation of Human Eosinophils

Eosinophil degranulation plays a crucial role in tissue inflammatory reactions associated with helminth parasitic nfections and allergic diseases. Paragonimus westermani, a lung fluke causing human paragonimiasis, secretes a large amount of cysteine proteases, which are involved in nutrient uptake, tissue invasion, and modulation of hos's immune responses. There is, however, limited information about the response of eosinophils to direct stimulation by cysteine proteases (CP) secreted by P. westermani. In the present study, we tested whether degranulation and superoxide production from human eosinophils can be induced by stimulation of the 2 CP (27 kDa and 28 kDa) purified from excretory-secretory products (ESP) of P. westermani newly excysted metacercariae (PwNEM). A large quantity of eosinophil-derived neurotoxin (EDN) was detected in the culture supernatant when human eosinophils isolated from the peripheral blood were incubated with the purified 27 kDa CP. Furthermore, the 27 kDa CP induced superoxide anion production by eosinophils in time- and dose-dependent manners. In contrast, the purified 28 kDa CP did not induce superoxide production and degranulation. These findings suggest that the 27 kDa CP secreted by PwNEM induces superoxide production and degranulation of human eosinophils, which may be involved in eosinophil-mediated tissue inflammatory responses during the larval migration in human paragonimiasis.

Partial Purification and Characterization of a Cysteine Protease Inhibitor from the Plerocercoid of Spirometra erinacei

Helminthic cysteine proteases are well known to play critical roles in tissue invasion, nutrient uptake, and immune evasion of the parasites. In the same manner, the sparganum, the plerocercoid of Spirometra mansoni, is also known to secrete a large amount of cysteine proteases. However, cysteine protease inhibitors regulating the proteolytic activities of the cysteine protease are poorly illustrated. In this regard, we partially purified an endogenous cysteine protease inhibitor from spargana and characterized its biochemical properties. The cysteine protease inhibitor was purified by sequential chromatographies using Resource Q anion exchanger and Superdex 200 HR gel filtration from crude extracts of spargana. The molecular weight of the purified protein was estimated to be about 11 kD on SDS-PAGE. It was able to inhibit papain and 27 kDa cysteine protease of spargana with the ratio of 25.7% and 49.1%, respectively, while did not inhibit chymotrypsin. This finding suggests that the cysteine protease inhibitor of spargana may be involved in regulation of endogenous cysteine proteases of the parasite, rather than interact with cysteine proteases from their hosts.

Characterization of HC58cDNA, a putative cysteine protease from the parasite Haemonchus contortus

Because of the complexity of the cathepsin B-like (CBL) family, an information on the biological and biochemical characteristics of individual CBL genes is lacking. In this study, we investigated the degradative effects of the recombinant HC58 protein isolated from Haemonchus contortus parasites on protein substrates over a broad pH range in vitro. This protein, which hydrolyzed the synthetic peptide substrates Z-FR-AMC and Z-RR-AMC, had characteristics of the cysteine protease class of proteins. In the acidic pH range, the isolated protein actively degraded hemoglobin (Hb), the heavy chain of goat immunoglobulin G, and azocasein. By contrast, it degraded fibrinogen in the alkaline pH range. These activities were strongly inhibited in the presence of the cysteine protease inhibitor E-64. While the protein digested Hb, it did not induce the agglutination of erythrocytes from its natural host. These results suggest that the HC58 protein may play a role in the nutrition of this parasite.

Degranulation of human eosinophils induced by Paragonimus westermani-secreted protease

Eosinophil degranulation is considered to be a key effector function for the killing of helminthic worms and tissue inflammation at worm-infected lesion sites. However, relatively little data are available with regard to eosinophil response after stimulation with worm-secreted products which contain a large quantity of cysteine proteases. In this study, we attempted to determine whether the degranulation of human eosinophils could be induced by the direct stimulation of the excretory-secretory products (ESP) of Paragonimus westermani, which causes pulmonary paragonimiasis in human beings. Incubation of eosinophils for 3 hr with Paragonimus-secreted products resulted in marked degranulation, as evidenced by the release of eosinophil-derived neurotoxin (EDN) in the culture supernatants. Moreover, superoxide anion was produced by eosinophils after stimulation of the ESP. The ESP-induced EDN release was found to be significantly inhibited when the ESP was pretreated with protease inhibitor cocktail or the cysteine protease inhibitor, E-64. These findings suggest that human eosinophils become degranulated in response to P. westermani-secreted proteases, which may contribute to in vivo tissue inflammation around the worms.

Partial characterization of a 29 kDa cysteine protease purified from Taenia solium metacestodes

A 29 kDa cysteine protease of Taenia solium metacestodes was purified by Mono Q anion-exchanger and Superose 6 HR gel filtration chromatography. The enzyme was effectively inhibited by cysteine protease inhibitors, such as iodoacetic acid (IAA) and trans-epoxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) while inhibitors acting on serine- or metallo-proteases did not affect the enzyme activity. The purified enzyme degraded human immunoglobulin G (IgG), collagen and bovine serum albumin (BSA), but human IgG was more susceptible for proteolysis by the enzyme. To define the precise biological roles of the enzyme, more detailed biochemical and functional studies would be required.

Expression and identification of cysteine proteinase from adult worm of Pagumogonimus skrjabini in Escherichia coli / 第三军医大学学报

Objective To express the recombinant antigen coded by Pagumogonimus skrjabini adult cysteine protease gene fragment and to investigate the immunoreactivity of the fusion protein for further usage on serodiagnosis of the fluke disease. Methods The target gene fragment was amplified by PCR. After purification with gel purification recoverykit, the target gene fragment was ligated with PinPointTM Xa 1 T vector and transduced into E.coli JM109 strain. The expressed fusion protein sample was prepared with alkaline lysis solution, and then analyzed by SDS PAGE. The expression level was determined by Coomassie blue staining and the streptavidin alkaline phosphatase staining. The immunoreactivity of fusion protein was examined by Western blotting. Results A total of 8 positive clones were harvested, and only one had the proper orientation verified by sequencing. The recombinant antigen was obtained after being induced with IPTG (Isopropltio ? D galactoside), and a positive band of 32?10 3 was found by streptavidin alkaline phosphatase staining. In the same position, the fusion protein was also detected by Western blotting. Conclusion The expression vector of adult cysteine protease gene PinPointTM Xa 1 T vector was successfully constructed. The recombinant antigen obtained after being induced with IPTG possesses good immunoreactivity.