scholarly journals Corrigendum

Parasitology ◽  
2007 ◽  
Vol 134 (4) ◽  
pp. 607-607
Keyword(s):  
Active Site ◽  
Active Enzyme ◽  
Distilled Water ◽  
Cysteine Proteinases ◽  
Anthelmintic Efficacy ◽  
Order Of Magnitude ◽  
Papaya Latex ◽  
Published Paper

Stepek, G., Lowe A. E., Buttle D. J., Duce I. R. and Behnke J. M. (2007). Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode, Protospirura muricola, in vitro and in vivo. Parasitology134, 103–112 (Published online 11 October 2006. doi:10.1017/S0031182006001302)The authors of the above article regret that several errors appear in their published paper:On Page 105: In the methods section entitled “In vivo assessment of anthelmintic efficacy of plant cysteine proteinases”, the sentence:‘Five grams of papaya latex were mixed with 8 ml of sterile distilled water (dH2O), filtered, and the amount of active enzyme present was measured, by active-site titration, to be 331 nmol’should read:‘Five grams of papaya latex were mixed with 8 ml of sterile distilled water (dH2O), filtered, and the amount of active enzyme present was measured, by active-site titration, to be 13·24 micromol’And the sentence:‘Each group of mice received a different treatment: 0·2 ml of papaya latex alone (containing 8 nmol active enzyme), …’should read:‘Each group of mice received a different treatment: 0·2 ml of papaya latex alone (containing 331 nmol active enzyme), …’On Page 110: In column 2, line 5, the sentence:‘The amount of active enzyme administered in each dose (8 nmol) is based …’should read:‘The amount of active enzyme administered in each dose (331 nmol) is based …’And on lines 10–15, the sentence:‘Assuming the volume of a mouse stomach to be 1 ml and the enzyme to be present throughout the stomach at equal dilution, the concentration of enzyme would be in the order of 8 microM, which is somewhat lower than the in vitro concentrations.’Should read:Assuming the volume of a mouse stomach to be 1 ml and the enzyme to be present throughout the stomach at equal dilution, the concentration of enzyme would be in the order of 330 microM, which is about an order of magnitude higher than effective in vitro concentrations. A possible reason for the …’

scholarly journals Anthelmintic action of plant cysteine proteinases against the rodent stomach nematode,Protospirura muricola,in vitroandin vivo

Parasitology ◽  
2006 ◽  
Vol 134 (1) ◽  
pp. 103-112 ◽  
Author(s):  
G. STEPEK ◽  
A. E. LOWE ◽  
D. J. BUTTLE ◽  
I. R. DUCE ◽  
J. M. BEHNKE
Keyword(s):  
Detrimental Effect ◽  
Gastrointestinal Nematodes ◽  
Cysteine Proteinases ◽  
Trichuris Muris ◽  
Kiwi Fruit ◽  
Heligmosomoides Polygyrus ◽  
Anthelmintic Efficacy ◽  
Papaya Latex

Cysteine proteinases from the fruit and latex of plants, including papaya, pineapple and fig, were previously shown to have a rapid detrimental effect,in vitro, against the rodent gastrointestinal nematodes,Heligmosomoides polygyrus(which is found in the anterior small intestine) andTrichuris muris(which resides in the caecum). Proteinases in the crude latex of papaya also showed anthelmintic efficacy against both nematodesin vivo. In this paper, we describe thein vitroandin vivoeffects of these plant extracts against the rodent nematode,Protospirura muricola, which is found in the stomach. As in earlier work, all the plant cysteine proteinases examined, with the exception of actinidain from the juice of kiwi fruit, caused rapid loss of motility and digestion of the cuticle, leading to death of the nematodein vitro. In vivo, in contrast to the efficacy againstH. polygyrusandT. muris, papaya latex only showed efficacy againstP. muricolaadult female worms when the stomach acidity had been neutralized prior to administration of papaya latex. Therefore, collectively, our studies have demonstrated that, with the appropriate formulation, plant cysteine proteinases have efficacy against nematodes residing throughout the rodent gastrointestinal tract.

The relative anthelmintic efficacy of plant-derived cysteine proteinases on intestinal nematodes

2013 ◽  
Vol 89 (2) ◽  
pp. 165-174 ◽  
Author(s):  
W. Luoga ◽  
F. Mansur ◽  
D.J. Buttle ◽  
I.R. Duce ◽  
M.C. Garnett ◽  
...  
Keyword(s):  
Ananas Comosus ◽  
Cysteine Proteinases ◽  
Kiwi Fruit ◽  
Intestinal Nematode ◽  
Anthelmintic Efficacy ◽  
Heligmosomoides Bakeri ◽  
Papaya Latex ◽  
Stem Bromelain

AbstractWe examined the in vitro and in vivo efficacy of plant cysteine proteinases (CPs) derived from pineapple (Ananas comosus) and kiwi fruit (Actinidia deliciosa), and compared their efficacy as anthelmintics to the known effects of CPs from the latex of papaya (Carica papaya) against the rodent intestinal nematode, Heligmosomoides bakeri. Both fruit bromelain and stem bromelain had significant in vitro detrimental effects on H. bakeri but in comparison, actinidain from kiwi fruit had very little effect. However, in vivo trials indicated far less efficacy of stem bromelain and fruit bromelain than that expected from the in vitro experiments (24.5% and 22.4% reduction in worm burdens, respectively) against H. bakeri. Scanning electron microscopy revealed signs of cuticular damage on worms incubated in fruit bromelain, stem bromelain and actinidain, but this was far less extensive than on those incubated in papaya latex supernatant. We conclude that, on the basis of presently available data, CPs derived from pineapples and kiwi fruits are not suitable for development as novel anthelmintics for intestinal nematode infections.

The anthelmintic efficacy of natural plant cysteine proteinases against Hymenolepis microstoma in vivo

2014 ◽  
Vol 89 (5) ◽  
pp. 601-611 ◽  
Author(s):  
F. Mansur ◽  
W. Luoga ◽  
D.J. Buttle ◽  
I.R. Duce ◽  
A. Lowe ◽  
...  
Keyword(s):  
Anthelmintic Activity ◽  
Cysteine Proteinases ◽  
Anthelmintic Efficacy ◽  
Novel Drugs ◽  
Papaya Latex ◽  
Host Parasite ◽  
Convenient Model ◽  
Hymenolepis Microstoma

AbstractLittle is known about the efficacy of cysteine proteinases (CP) as anthelmintics for cestode infections in vivo. Hymenolepis microstoma is a natural parasite of house mice, and provides a convenient model system for the assessment of novel drugs for anthelmintic activity against cestodes. The experiments described in this paper indicate that treatment of H. microstoma infections in mice with the supernatant of papaya latex (PLS), containing active cysteine proteinases, is only minimally efficacious. The statistically significant effects seen on worm burden and biomass showed little evidence of dose dependency, were temporary and the role of cysteine proteinases as the active principles in PLS was not confirmed by specific inhibition with E-64. Worm fecundity was not affected by treatment at the doses used. We conclude also that this in vivo host–parasite system is not sensitive enough to be used reliably for the detection of cestocidal activity of compounds being screened as potential, novel anthelmintics.

The anthelmintic efficacy of natural plant cysteine proteinases against the equine tapeworm, Anoplocephala perfoliatain vitro

2015 ◽  
Vol 90 (5) ◽  
pp. 561-568 ◽  
Author(s):  
F. Mansur ◽  
W. Luoga ◽  
D.J. Buttle ◽  
I.R. Duce ◽  
A.E. Lowe ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Hymenolepis Diminuta ◽  
Cysteine Proteinases ◽  
Active Ingredients ◽  
Natural Plant ◽  
Nematode Parasites ◽  
Anthelmintic Efficacy ◽  
Anoplocephala Perfoliata ◽  
Papaya Latex

AbstractPapaya latex has been demonstrated to be an efficacious anthelmintic against murine, porcine, ovine and canine nematode parasites, and even those infecting poultry, and it has some efficacy against rodent cestodes. The active ingredients of papaya latex are known to be cysteine proteinases (CPs). The experiments described in this paper indicate that CPs in papaya latex, and also those in pineapples, are highly efficacious against the equine cestode Anoplocephala perfoliatain vitro, by causing a significant reduction in motility leading to death of the worms. The susceptibility of A. perfoliata to damage by CPs was considerably greater than that of the rodent cestodes Hymenolepis diminuta and H. microstoma. Our results are the first to report anthelmintic efficacy of CPs against an economically important equine helminth. Moreover, they provide further evidence that the spectrum of activity of CPs is not restricted to nematodes and support the idea that these plant-derived enzymes can be developed into useful broad-spectrum anthelmintics.

scholarly journals Nematicidal effects of cysteine proteinases against sedentary plant parasitic nematodes

Parasitology ◽  
2007 ◽  
Vol 134 (12) ◽  
pp. 1831-1838 ◽  
Author(s):  
G. STEPEK ◽  
R. H. C. CURTIS ◽  
B. R. KERRY ◽  
P. R. SHEWRY ◽  
S. J. CLARK ◽  
...  
Keyword(s):  
Plant Extracts ◽  
Specific Inhibitor ◽  
Parasitic Nematodes ◽  
Cysteine Proteinases ◽  
Plant Parasitic Nematodes ◽  
Second Stage ◽  
Anthelmintic Efficacy ◽  
Plant Parasitic

SUMMARYCysteine proteinases from the fruit and latex of plants, such as papaya, pineapple and fig, have previously been shown to have substantial anthelmintic efficacy, in vitro and in vivo, against a range of animal parasitic nematodes. In this paper, we describe the in vitro effects of these plant extracts against 2 sedentary plant parasitic nematodes of the genera Meloidogyne and Globodera. All the plant extracts examined caused digestion of the cuticle and decreased the activity of the tested nematodes. The specific inhibitor of cysteine proteinases, E-64, blocked this activity completely, indicating that it was essentially mediated by cysteine proteinases. In vitro, plant cysteine proteinases are active against second-stage juveniles of M. incognita and M. javanica, and some cysteine proteinases also affect the second-stage juveniles of Globodera rostochiensis. It is not known yet whether these plant extracts will interfere with, or prevent invasion of, host plants.

Ancylostoma caninum Anticoagulant Peptide Blocks Metastasis In Vivo and Inhibits Factor Xa Binding to Melanoma Cells In Vitro

1998 ◽  
Vol 79 (05) ◽  
pp. 1041-1047 ◽  
Author(s):  
Kathleen M. Donnelly ◽  
Michael E. Bromberg ◽  
Aaron Milstone ◽  
Jennifer Madison McNiff ◽  
Gordon Terwilliger ◽  
...  
Keyword(s):  
Active Site ◽  
Thrombin Generation ◽  
Factor Xa ◽  
Coagulation Factor ◽  
Melanoma Cells ◽  
Factor V ◽  
Ancylostoma Caninum ◽  
Metastatic Activity

SummaryWe evaluated the in vivo anti-metastatic activity of recombinant Ancylostoma caninum Anticoagulant Peptide (rAcAP), a potent (Ki = 265 pM) and specific active site inhibitor of human coagulation factor Xa originally isolated from bloodfeeding hookworms. Subcutaneous injection of SCID mice with rAcAP (0.01-0.2 mg/mouse) prior to tail vein injection of LOX human melanoma cells resulted in a dose dependent reduction in pulmonary metastases. In order to elucidate potential mechanisms of rAcAP’s anti-metastatic activity, experiments were carried out to identify specific interactions between factor Xa and LOX. Binding of biotinylated factor Xa to LOX monolayers was both specific and saturable (Kd = 15 nM). Competition experiments using antibodies to previously identified factor Xa binding proteins, including factor V/Va, effector cell protease receptor-1, and tissue factor pathway inhibitor failed to implicate any of these molecules as significant binding sites for Factor Xa. Functional prothrombinase activity was also supported by LOX, with a half maximal rate of thrombin generation detected at a factor Xa concentration of 2.4 nM. Additional competition experiments using an excess of either rAcAP or active site blocked factor Xa (EGR-Xa) revealed that most of the total factor Xa binding to LOX is mediated via interaction with the enzyme’s active site, predicting that the vast majority of cell-associated factor Xa does not participate directly in thrombin generation. In addition to establishing two distinct mechanisms of factor Xa binding to melanoma, these data raise the possibility that rAcAP’s antimetastatic effect in vivo might involve novel non-coagulant pathways, perhaps via inhibition of active-site mediated interactions between factor Xa and tumor cells.

scholarly journals Ultra-strong bio-glue from genetically engineered polypeptides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Ma ◽  
Jing Sun ◽  
Bo Li ◽  
Yang Feng ◽  
Yao Sun ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Covalent Bond ◽  
Genetically Engineered ◽  
Supramolecular Interactions ◽  
Molar Ratio ◽  
High Adhesion ◽  
Strong Adhesion ◽  
Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

scholarly journals Important Role for Phylogenetically Invariant PP2Acα Active Site and C-Terminal Residues Revealed by Mutational Analysis in Saccharomyces cerevisiae

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 21-29 ◽  
Author(s):  
David R H Evans ◽  
Brian A Hemmings
Keyword(s):  
Protein Interactions ◽  
Active Site ◽  
Protein Function ◽  
Mutational Analysis ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Active Site Residues ◽  
Catalytic Function

Abstract PP2A is a central regulator of eukaryotic signal transduction. The human catalytic subunit PP2Acα functionally replaces the endogenous yeast enzyme, Pph22p, indicating a conservation of function in vivo. Therefore, yeast cells were employed to explore the role of invariant PP2Ac residues. The PP2Acα Y127N substitution abolished essential PP2Ac function in vivo and impaired catalysis severely in vitro, consistent with the prediction from structural studies that Tyr-127 mediates substrate binding and its side chain interacts with the key active site residues His-118 and Asp-88. The V159E substitution similarly impaired PP2Acα catalysis profoundly and may cause global disruption of the active site. Two conditional mutations in the yeast Pph22p protein, F232S and P240H, were found to cause temperature-sensitive impairment of PP2Ac catalytic function in vitro. Thus, the mitotic and cell lysis defects conferred by these mutations result from a loss of PP2Ac enzyme activity. Substitution of the PP2Acα C-terminal Tyr-307 residue by phenylalanine impaired protein function, whereas the Y307D and T304D substitutions abolished essential function in vivo. Nevertheless, Y307D did not reduce PP2Acα catalytic activity significantly in vitro, consistent with an important role for the C terminus in mediating essential protein-protein interactions. Our results identify key residues important for PP2Ac function and characterize new reagents for the study of PP2A in vivo.

scholarly journals Phosphorylation-dependent interaction of the synaptic vesicle proteins cysteine string protein and synaptotagmin I

2002 ◽  
Vol 364 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Gareth J.O. EVANS ◽  
Alan MORGAN
Keyword(s):  
Rat Brain ◽  
Direct Interaction ◽  
Secretory Vesicle ◽  
Brain Membrane ◽  
Synaptotagmin I ◽  
Phosphorylated Form ◽  
Order Of Magnitude ◽  
And Function

The secretory vesicle cysteine string proteins (CSPs) are members of the DnaJ family of chaperones, and function at late stages of Ca2+-regulated exocytosis by an unknown mechanism. To determine novel binding partners of CSPs, we employed a pull-down strategy from purified rat brain membrane or cytosolic proteins using recombinant hexahistidine-tagged (His6-)CSP. Western blotting of the CSP-binding proteins identified synaptotagmin I to be a putative binding partner. Furthermore, pull-down assays using cAMP-dependent protein kinase (PKA)-phosphorylated CSP recovered significantly less synaptotagmin. Complexes containing CSP and synaptotagmin were immunoprecipitated from rat brain membranes, further suggesting that these proteins interact in vivo. Binding assays in vitro using recombinant proteins confirmed a direct interaction between the two proteins and demonstrated that the PKA-phosphorylated form of CSP binds synaptotagmin with approximately an order of magnitude lower affinity than the non-phosphorylated form. Genetic studies have implicated each of these proteins in the Ca2+-dependency of exocytosis and, since CSP does not bind Ca2+, this novel interaction might explain the Ca2+-dependent actions of CSP.

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