Characterization of proteinases in extracts of adultHaemonchus contortus, the ovine abomasal nematode

Parasitology ◽  
1993 ◽  
Vol 106 (4) ◽  
pp. 395-404 ◽  
Author(s):  
D. P. Knox ◽  
D. L. Redmond ◽  
D. G. Jones
Keyword(s):  
Immune Responses ◽  
Haemonchus Contortus ◽  
Cysteine Proteinase ◽  
Molecular Size ◽  
Acidic Ph ◽  
Blood Proteins ◽  
Protein Substrates ◽  
Host Immune Responses ◽  
Ph Range

SUMMARYThe degradation of several protein substrates, including the blood proteins haemoglobin, albumin and fibrinogen, by proteinases present in extracts of adultHaemonchus contortuswas examined over a broad pH range. These proteinases were further characterized on the basis of substrate specificity, inhibitor sensitivity and molecular size by spectrophotometric and substrate gel analysis. The majority of the proteinases capable of degrading the blood proteins tested were active at acidic pH and could be ascribed to the cysteine proteinase class. In addition, evidence is presented that these proteinases are differentially recognized and inhibited by immune sera and that parasites capable of withstanding protective host immune responses exhibit modified expression of proteinases.

scholarly journals Affinity purification of the novel cysteine proteinase papaya proteinase IV, and papain from papaya latex

1989 ◽  
Vol 261 (2) ◽  
pp. 469-476 ◽  
Author(s):  
D J Buttle ◽  
A A Kembhavi ◽  
S L Sharp ◽  
R E Shute ◽  
D H Rich ◽  
...  
Keyword(s):  
Cysteine Proteinase ◽  
Affinity Purification ◽  
Molecular Size ◽  
Exchange Chromatography ◽  
The Novel ◽  
Protein Substrates ◽  
Papaya Latex ◽  
Sepharose 4B ◽  
Spray Dried

A procedure is described for the purification of a previously undetected cysteine proteinase, which we have called papaya proteinase IV, from spray-dried latex of the papaya (Carica papaya) plant. The purification involves affinity chromatography on Gly-Phe-aminoacetonitrile linked to CH-Sepharose 4B, with elution by 2-hydroxyethyl disulphide at pH 4.5. The product thus obtained is a mixture of almost fully active papain and papay proteinase IV, which are then separated by cation-exchange chromatography. A preliminary characterization of papaya proteinase IV showed it to be very similar to chymopapain in both molecular size and charge. However, the new enzyme is immunologically distinct from the previously characterized cysteine proteinases of papaya latex. It also differs in its lack of activity against the synthetic substrates of the other papaya proteinases, in its narrow specificity against protein substrates and its lack of inhibition by chicken cystatin. Papaya proteinase IV is abundant, contributing almost 30% of the protein in spray-dried papaya latex, and contamination of chymopapain preparations with this enzyme may account for some of the previously reported heterogeneity of chymopapain.

Molecular characterization of a family of metalloendopeptidases from the intestinal brush border of Haemonchus contortus

Parasitology ◽  
2006 ◽  
Vol 133 (3) ◽  
pp. 357-368 ◽  
Author(s):  
G. F. J. NEWLANDS ◽  
P. J. SKUCE ◽  
A. J. NISBET ◽  
D. L. REDMOND ◽  
S. K. SMITH ◽  
...  
Keyword(s):  
Haemonchus Contortus ◽  
Proteomic Analysis ◽  
Parasitic Nematode ◽  
Integral Membrane Protein ◽  
Cleavage Sites ◽  
Molecular Architecture ◽  
Intestinal Brush Border ◽  
Typical Type ◽  
Ph Range

Substantial protection against the economically important parasitic nematode Haemonchus contortus has been achieved by immunizing sheep with a glycoprotein fraction isolated from the intestinal membranes of the worm (H-gal-GP). Previous studies showed that one of the major components of H-gal-GP is a family of at least 4 zinc metalloendopeptidases, designated MEPs 1–4. This paper describes aspects of the molecular architecture of this protease family, including the proteomic analysis of the MEP fraction of the H-gal-GP complex. These enzymes belong to the M13 zinc metalloendopeptidase family (EC 3.4.24.11), also known as neutral endopeptidases or neprilysins. The sequences of MEPs 1 and 3 suggested a typical Type II integral membrane protein structure, whilst MEPs 2 and 4 had putative cleavable signal peptides, typical of secreted proteins. Proteomic analysis of H-gal-GP indicated that the extracellular domain of all 4 MEPs had been cleaved close to the transmembrane region/signal peptide with additional cleavage sites mid-way along the polypeptide. MEP3 was present as a homo-dimer in H-gal-GP, whereas MEP1 or MEP2 formed hetero-dimers with MEP4. It was found that expression of MEP3 was confined to developing 4th-stage larvae and to adult worms, the stages of Haemonchus which feed on blood. MEP-like activity was detected in the H-gal-GP complex over a broad pH range (5–9). Since all 4 MEPs must share a similar microenvironment in the complex, this suggests that each might have a different substrate specificity.

Partial protease activity characterization of squid (Todaropsis eblanae) mantle / Caracterización parcial de la actividad proteolítica del manto de pota (Todaropsis eblanae)

1999 ◽  
Vol 5 (5) ◽  
pp. 391-396 ◽  
Author(s):  
M.G. Ayensa ◽  
H. An ◽  
M.C. Gómez-Guillén ◽  
P. Montero ◽  
A.J. Borderías
Keyword(s):  
Cathepsin B ◽  
Protease Activity ◽  
Cysteine Proteases ◽  
Acidic Ph ◽  
Alkaline Proteases ◽  
Alkaline Ph ◽  
Serine Protease Activity ◽  
Lysosomal Cysteine Proteases ◽  
Ph Range

Proteolytic activity in mantle of Todaropsis eblanae was maximum at 40 and 65 °C. Several peaks of activity were detected over the pH range studied (1.5-9.5), indicating the presence of acidic, neutral and alkaline proteases, depending on the temperature. The substantial enzymic inhibition at acidic pH by the inhibitor trans-epoxysuccinyl-L-leucylamine-4-guanidine butane (E-64) revealed the pre dominance of lysosomal cysteine proteases (cathepsins) which showed higher activity at 65 °C than at 40 °C. At 65 °C and pH 5.5 metallo-proteases were also detected by the inhibition with phenanthroline. Serine protease activity predominated at neutral pH (higher at 40 °C than at 65 °C), and cysteine proteases were detected at alkaline pH. There was evidence of cathepsin B and L activity at 65 °C and to a lesser degree at 40 °C.

Proteinases released in vitro by the parasitic stages of Teladorsagia circumcincta, an ovine abomasal nematode

Parasitology ◽  
1995 ◽  
Vol 110 (4) ◽  
pp. 465-471 ◽  
Author(s):  
C. J. Young ◽  
J. B. McKeand ◽  
D. P. Knox
Keyword(s):  
Molecular Size ◽  
Dependent Manner ◽  
Acidic Ph ◽  
Alkaline Ph ◽  
Protein Substrates ◽  
Teladorsagia Circumcincta ◽  
Fourth Larval Stage ◽  
Sensitivity Studies ◽  
Ph Dependent

SUMMARYProteinases released during in vitro maintenance of third (L3) and fourth larval stage (L4) and adult Teladorsagia circumcincta (formerly Ostertagia circumcincta), an ovine abomasal nematode parasite, were characterized on the basis of pH optima, molecular size and specific proteinase inhibitor sensitivity. Enzyme activity was maximal at alkaline pH and stage-specific release was demonstrated. Proteinases released by the adult parasite degraded a variety of protein substrates including plasminogen, albumin and haemoglobin, in a pH-dependent manner. At alkaline pH fibrinogen degradation was restricted to the α and β peptide chains although the γ peptide chain was also degraded at acidic pH. Inhibitor sensitivity studies indicated that degradation was predominantly due to metalloproteinases although aspartyl proteinase activity was indicated at acidic pH.

Characterization of proteinases in different isolates of adult Haemonchus contortus

Parasitology ◽  
2004 ◽  
Vol 130 (4) ◽  
pp. 429-435 ◽  
Author(s):  
D. L. REDMOND ◽  
R. WINDHAM
Keyword(s):  
Haemonchus Contortus ◽  
Specific Activity ◽  
Molecular Size ◽  
Integral Membrane Protein ◽  
Proteinase Activity ◽  
Effective Vaccine ◽  
Wide Ph Range ◽  
Ph Range ◽  
Different Strains ◽  
High Degree

A high degree of intra- and inter-geographical variation has been demonstrated previously in the excretory/secretory proteinases released by adult Haemonchus contortus. Proteinase activity has also been associated with host-protective ‘hidden’ antigens isolated from the gut of adult H. contortus. If similar geographical strain variation also exists within the gut-associated proteinases, this will have important implications for the development of a globally effective vaccine. The proteinases active in integral-membrane protein extracts from 3 different strains of adult H. contortus were characterized on the basis of their pH optima and molecular size. Although enzyme activity was detected over a wide pH range, the majority of proteinase activity was detected at acidic pH. Differences in specific activity and size of enzymes were observed between the 3 different parasite strains at different pH values. A high degree of conservation in reactive peptides was observed when protein extracts were probed with antisera raised to the protective hidden gut-antigen complexes isolated from the Moredun strain of H. contortus, or to bacterially expressed subcomponents thereof. Therefore, despite the observed differences in membrane-bound proteinase profiles, the similarity of the immunogenic response against these hidden antigens may be sufficient to prove protective against different geographical isolates of H. contortus.

Characterization of host immune responses in Ebola virus infections

2014 ◽  
Vol 10 (6) ◽  
pp. 781-790 ◽  
Author(s):  
Gary Wong ◽  
Gary P Kobinger ◽  
Xiangguo Qiu
Keyword(s):  
Immune Responses ◽  
Ebola Virus ◽  
Virus Infections ◽  
Host Immune Responses
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