Displaying publications 1 - 20 of 22 in total

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  1. Lim KJ
    Malays J Pathol, 2003 Jun;25(1):1-13.
    PMID: 16196373
    Successful human reproduction remains an enigma, but this is slowly changing in the current era of expanding scientific knowledge. The discovery of various molecular factors such as adhesion molecules, proteases and cytokines have in recent years been at the forefront of medical research. The growing importance of immunology in particular has led to novel new immuno-modulatory therapies and increasing research into this new aspect of reproductive immunology may well prove to be the most important breakthrough in understanding the fundamentals of human reproduction. Implantation represents the first step in the complex interactions and processes involved in foetal-maternal interaction, which continues throughout pregnancy gestation and culminates in the birth of an infant. It is therefore vital that we understand the myriad processes controlling implantation in order to build a firm foundation for exploring reproductive immunology research in the new millennium. This review brings together and presents an overview of the potential roles of currently known molecular factors such as adhesion molecules, proteases, cytokines and its interaction with the maternal immune response, incorporating the findings of previous published research performed by the author on cytokines and reproductive immunology.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  2. Shavandi A, Hu Z, Teh S, Zhao J, Carne A, Bekhit A, et al.
    Food Chem, 2017 Jul 15;227:194-201.
    PMID: 28274422 DOI: 10.1016/j.foodchem.2017.01.099
    Squid pens were subjected to alkali hydrolysis to extract chitin and chitosan. Proteins present in the alkaline extraction wastewater were recovered at pH 3, 4, 5 and 6, and were subjected to hydrolysis by trypsin, pepsin and a bacterial protease called HT for 1, 2, 4 and 24h. Hydrolysis of the extracted proteins with either trypsin or HT generated more antioxidant activity than hydrolysis with pepsin. Higher ACE-inhibitory activity was generated in the trypsin and pepsin hydrolysates than in the HT hydrolysate. Squid pen protein recovered from chitosan processing waste alkaline solution can be a potential source of bioactive peptides for addition to foods. The antioxidant and ACE-inhibitory activities of the extracted proteins were initially low and increased upon incubation with the proteases. Pepsin generated significantly lower (P<0.05) antioxidant activities compared to trypsin and HT, while trypsin and pepsin hydrolysates exhibited higher ACE-inhibitory activity than HT (P<0.05).
    Matched MeSH terms: Peptide Hydrolases/metabolism
  3. Romano N, Ashikin M, Teh JC, Syukri F, Karami A
    Environ Pollut, 2018 Jun;237:1106-1111.
    PMID: 29157968 DOI: 10.1016/j.envpol.2017.11.040
    Silver barb Barbodes gonionotus fry were exposed to polyvinyl chloride (PVC) fragments at increasing concentrations of 0.2, 0.5 and 1.0 mg/L for 96 h, following which whole body histological evaluation and analysis of the digestive enzymes trypsin and chymotrypsin were performed. Whole body trypsin and chymotrypsin activities increased significantly in fish exposed to 0.5 and 1.0 mg/L PVC as compared those exposed to zero or 0.2 mg/L PVC. In fish exposed to all tested concentrations, PVCs were observed in both the proximal and distal intestine, and fish exposed to 0.5-1.0 and 1.0 mg/L PVC, respectively, and these particles were associated with localized thickening of the mucosal epithelium. No tissue damage was evident in any other internal organs or gills. This lack of damage may be attributed to the absence of contaminants associated with the PVC fragments and their relatively smooth surface. The increased whole body trypsin and chymotrypsin activities may indicate an attempt to enhance digestion to compensate for epithelial thickening of the intestine and/or to digest the plastics.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  4. Darah I, Nur-Diyana A, Nurul-Husna S, Jain K, Lim SH
    Appl Biochem Biotechnol, 2013 Dec;171(7):1900-10.
    PMID: 24013862 DOI: 10.1007/s12010-013-0496-4
    Keratinous wastes have increasingly become a problem and accumulate in the environment mainly in the form of feathers, generated mainly from a large number of poultry industries. As keratins are very difficult to degrade by general proteases, they pose a major environmental problem. Therefore, microorganisms which would effectively degrade keratins are needed for recycling such wastes. A geophilic dermatophyte, Microsporum fulvum IBRL SD3 which was isolated from a soil sample collected from a chicken feather dumping site using a baiting technique, was capable to produce keratinase significantly. The crude keratinase was able to degrade whole chicken feathers effectively. The end product of the degradation was protein that contained essential amino acids and may have potential application in animal feed production. Thus, M. fulvum could be a novel organism to produce keratinase for chicken feathers degradation.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  5. Gokulshankar S, Ranjitsingh A, Venkatesan G, Ranjith MS, Vijayalakshmi GS, Prabhamanju M, et al.
    Indian J Pathol Microbiol, 2010 Jan-Mar;53(1):87-92.
    PMID: 20090230 DOI: 10.4103/0377-4929.59191
    The protease activity of different isolates of dermatophytes representing different ecological groups namely geophilic, zoopahilic and anthropophilic, in their vegetative and sporulation growth phases were compared. Unlike their geophilic and zoophilic counterparts, all the isolates of anthropophilic dermatophytes viz. Trichophyton rubrum, T. mentagrophytes, T. tonsurans, T. violaceum and Epidermophyton floccosum recorded reduced protease activity during artificially induced sporulation phase in comparison to their vegetative growth phase. Even among the anthropophilic group, a classical moderation of protease activity was recorded in Trichyphyton rubrum which also correlates to its clinical manifestation. This enzyme moderation could also be an evolutionary adaptation of the anthropization of these species.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  6. Othman R, Kiat TS, Khalid N, Yusof R, Newhouse EI, Newhouse JS, et al.
    J Chem Inf Model, 2008 Aug;48(8):1582-91.
    PMID: 18656912 DOI: 10.1021/ci700388k
    A group of flavanones and their chalcones, isolated from Boesenbergia rotunda L., were previously reported to show varying degrees of noncompetitive inhibitory activities toward Dengue virus type 2 (Den2) protease. Results obtained from automated docking studies are in agreement with experimental data in which the ligands were shown to bind to sites other than the active site of the protease. The calculated K(i) values are very small, indicating that the ligands bind quite well to the allosteric binding site. Greater inhibition by pinostrobin, compared to the other compounds, can be explained by H-bonding interaction with the backbone carbonyl of Lys74, which is bonded to Asp75 (one of the catalytic triad residues). In addition, structure-activity relationship analysis yields structural information that may be useful for designing more effective therapeutic drugs against dengue virus infections.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  7. Thevarajoo S, Selvaratnam C, Chan KG, Goh KM, Chong CS
    Mar Genomics, 2015 Oct;23:49-50.
    PMID: 25957696 DOI: 10.1016/j.margen.2015.04.009
    Type strain Vitellibacter vladivostokensis KMM 3516(T) (=NBRC 16718(T)) belongs to the phylum Cytophaga-Flavobacterium-Bacteroides. To date, no genomes of the Vitellibacter spp. have been reported, and their metabolic pathways are unknown. This study reports the draft genome sequence of V. vladivostokensis. Moreover, mining of genes associated with proteolytic enzymes was performed to provide insights for further enzyme characterization.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  8. Hashim OH, Hassan H
    Immunology, 1991 Jun;73(2):235-8.
    PMID: 2071167
    Three bacterial species of Clostridium (septicum, tertium and sporogenes) were identified to produce extracellular proteases cleaving IgA to Fab and Fc fragments, as demonstrated by SDS-PAGE and immunoelectrophoretic procedures. These enzymes acted on monometric IgA1 paraproteins and normal serum IgA1 but had no activity on IgA2 paraproteins and intact secretory IgA1 from human colostrum. Their action on polyclonal serum IgA1 suggested the absence of neutralizing anti-clostridial IgA protease activity. Although the enzymes were shown not to act on secretory IgA1, they were, however, able to digest free alpha-heavy chains of the dimeric IgA molecules. Susceptibility of the alpha-heavy chain to the proteases was more likely due to the change to a more accessible conformation than because of the absence of neutralizing anti-enzymic activity.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  9. Raftari M, Ghafourian S, Abu Bakar F
    J Appl Microbiol, 2017 Apr;122(4):1009-1019.
    PMID: 28028882 DOI: 10.1111/jam.13388
    AIMS: This study was an attempt to create a novel milk clotting procedure using a recombinant bacterium capable of milk coagulation.

    METHODS AND RESULTS: The Rhizomucor pusillus proteinase (RPP) gene was sub-cloned into a pALF expression vector. The recombinant pALF-RPP vector was then electro-transferred into Lactococcus lactis. Finally, the milk coagulation ability of recombinant L. lactis carrying a RPP gene was evaluated. Nucleotide sequencing of DNA insertion from the clone revealed that the RPP activity corresponded to an open reading frame consisting of 1218 bp coding for a 43·45 kDa RPP protein. The RPP protein assay results indicated that the highest RPP enzyme expression with 870 Soxhlet units (SU) per ml and 7914 SU/OD were obtained for cultures which were incubated at pH 5·5 and 30°C. Interestingly, milk coagulation was observed after 205 min of inoculating milk with recombinant L. lactis carrying the RPP gene.

    CONCLUSION: The recombinant L. lactis carrying RPP gene has the ability to function as a starter culture for acidifying and subsequently coagulating milk by producing RPP as a milk coagulant agent.

    SIGNIFICANCE AND IMPACT OF THE STUDY: Creating a recombinant starter culture bacterium that is able to coagulate milk. It is significant because the recombinant L. lactis has the ability to work as a starter culture and milk coagulation agent.

    Matched MeSH terms: Peptide Hydrolases/metabolism
  10. Chin VK, Basir R, Nordin SA, Abdullah M, Sekawi Z
    Int Microbiol, 2020 May;23(2):127-136.
    PMID: 30875033 DOI: 10.1007/s10123-019-00067-3
    Human leptospirosis is considered as one of the most widespread and potentially fatal zoonotic diseases that causes high mortality and morbidity in the endemic regions of tropical and subtropical countries. The infection can arise from direct or indirect exposure of human through contaminated environment that contains leptospires or animal reservoirs that carry leptospires. The clinical manifestations during human leptospirosis ranges from asymptomatic, mild infections to severe and life-threatening complications involving multi-organ failures with kidneys, lungs and liver severely affected. Despite much efforts have been put in to unravel the pathogenesis during human leptospirosis, it remains obscure to which extent the host factors or the pathogen itself contribute towards the pathogenesis. Host innate immunity, especially, polymorphonuclear neutrophils and complement system are involved in the first line of defense during human leptospirosis. However, pathogenic Leptospira has acquired diverse evasion strategies to evade from host immunity and establish infection in infected hosts. Hence, in this review, we focus on organs pathology during human leptospiral infection and host evasion strategies employed by Leptospira. A profound understanding on leptospiral immunity and how Leptospira subvert the immune system may provide new insights on the development of therapeutic regimens against this species in future.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  11. ElFar OA, Billa N, Lim HR, Chew KW, Cheah WY, Munawaroh HSH, et al.
    Bioengineered, 2022 Jun;13(6):14681-14718.
    PMID: 35946342 DOI: 10.1080/21655979.2022.2100863
    Arthrospira platensis (A. platensis) aqueous extract has massive amounts of natural products that can be used as future drugs, such as C-phycocyanin, allophycocyanin, etc. This extract was chosen because of its high adaptability, which reflects its resolute genetic composition. The proactive roles of cyanobacteria, particularly in the medical field, have been discussed in this review, including the history, previous food and drug administration (FDA) reports, health benefits and the various dose-dependent therapeutic functions that A. platensis possesses, including its role in fighting against lethal diseases such as cancer, SARS-CoV-2/COVID-19, etc. However, the remedy will not present its maximal effect without the proper delivery to the targeted place for deposition. The goal of this research is to maximize the bioavailability and delivery efficiency of A. platensis constituents through selected sites for effective therapeutic outcomes. The solutions reviewed are mainly on parenteral and tablet formulations. Moreover, suggested enteric polymers were discussed with minor composition variations applied for better storage in high humid countries alongside minor variations in the polymer design were suggested to enhance the premature release hindrance of basic drugs in low pH environments. In addition, it will open doors for research in delivering active pharmaceutical ingredients (APIs) in femtoscale with the use of various existing and new formulations.Abbrevations: SDGs; Sustainable Development Goals, IL-4; Interleukin-4, HDL; High-Density Lipoprotein, LDL; Low-Density Lipoprotein, VLDL; Very Low-Density Lipoprotein, C-PC; C-Phycocyanin, APC; Allophycocyanin, PE; Phycoerythrin, COX-2; Cyclooxygenase-2, RCTs; Randomized Control Trials, TNF-α; Tumour Necrosis Factor-alpha, γ-LFA; Gamma-Linolenic Fatty Acid, PGs; Polyglycans, PUFAs: Polyunsaturated Fatty Acids, NK-cell; Natural Killer Cell, FDA; Food and Drug Administration, GRAS; Generally Recognized as Safe, SD; Standard Deviation, API; Active Pharmaceutical Ingredient, DW; Dry Weight, IM; Intramuscular, IV; Intravenous, ID; Intradermal, SC; Subcutaneous, AERs; Adverse Event Reports, DSI-EC; Dietary Supplement Information Executive Committee, cGMP; Current Good Manufacturing Process, A. platensis; Arthrospira platensis, A. maxima; Arthrospira maxima, Spirulina sp.; Spirulina species, Arthrospira; Spirulina, Tecuitlatl; Spirulina, CRC; Colorectal Cancer, HDI; Human Development Index, Tf; Transferrin, TfR; Transferrin Receptor, FR; Flow Rate, CPP; Cell Penetrating Peptide, SUV; Small Unilamenar Vesicle, LUV; Large Unilamenar Vesicle, GUV; Giant Unilamenar Vesicle, MLV; Multilamenar Vesicle, COVID-19; Coronavirus-19, PEGylated; Stealth, PEG; Polyethylene Glycol, OSCEs; Objective Structured Clinical Examinations, GI; Gastrointestinal Tract, CAP; Cellulose Acetate Phthalate, HPMCP, Hydroxypropyl Methyl-Cellulose Phthalate, SR; Sustained Release, DR; Delay Release, Poly(MA-EA); Polymethyl Acrylic Co-Ethyl Acrylate, f-DR L-30 D-55; Femto-Delay Release Methyl Acrylic Acid Co-Ethyl Acrylate Polymer, MW; Molecular Weight, Tg; Glass Transition Temperature, SN2; Nucleophilic Substitution 2, EPR; Enhance Permeability and Retention, VEGF; Vascular Endothelial Growth Factor, RGD; Arginine-Glycine-Aspartic Acid, VCAM-1; Vascular Cell Adhesion Molecule-1, P; Coefficient of Permeability, PES; Polyether Sulfone, pHe; Extracellular pH, ζ-potential; Zeta potential, NTA; Nanoparticle Tracking Analysis, PB; Phosphate Buffer, DLS; Dynamic Light Scattering, AFM; Atomic Force Microscope, Log P; Partition Coefficient, MR; Molar Refractivity, tPSA; Topological Polar Surface Area, C log P; Calculated Partition Coefficient, CMR; Calculated Molar Refractivity, Log S; Solubility Coefficient, pka; Acid Dissociation Constant, DDAB; Dimethyl Dioctadecyl Ammonium Bromide, DOPE; Dioleoylphosphatidylethanolamine, GDP; Good Distribution Practice, RES; Reticuloendothelial System, PKU; Phenylketonuria, MS; Multiple Sclerosis, SLE; Systemic Lupus Erythematous, NASA; National Aeronautics and Space Administration, DOX; Doxorubicin, ADRs; Adverse Drug Reactions, SVM; Support Vector Machine, MDA; Malondialdehyde, TBARS; Thiobarbituric Acid Reactive Substances, CRP; C-Reactive Protein, CK; Creatine Kinase, LDH; Lactated Dehydrogenase, T2D; Type 2 Diabetes, PCB; Phycocyanobilin, PBP; Phycobiliproteins, PEB; Phycoerythrobilin, DPP-4; Dipeptidyl Peptidase-4, MTT; 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, IL-2; Interleukin-2, IL-6; Interleukin-6, PRISMA; Preferred Reporting Items for Systematic Reviews and Meta-Analyses, STATA; Statistics, HepG2; Hepatoblastoma, HCT116; Colon Cancer Carcinoma, Kasumi-1; Acute Leukaemia, K562; Chronic Leukaemia, Se-PC; Selenium-Phycocyanin, MCF-7; Breast Cancer Adenocarcinoma, A375; Human Melanoma, RAS; Renin-Angiotensin System, IQP; Ile-Gln-Pro, VEP; Val-Glu-Pro, Mpro; Main Protease, PLpro; Papin-Like Protease, BMI; Body Mass Index, IC50; Inhibitory Concentration by 50%, LD50; Lethal Dose by 50%, PC12 Adh; Rat Pheochromocytoma Cells, RNS; Reactive Nitrogen Species, Hb1Ac; hemoglobin A1c.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  12. Azila N, Othman I
    Biochem. Int., 1990;20(2):291-9.
    PMID: 1969267
    An extract prepared from the tentacle of Catostylus mosaicus was shown to lyse erythrocytes from rat, rabbit and human to a different extent; those from the rat being most susceptible followed by those from rabbit and human. The haemolytic activity was dependent on the concentration of crude extract protein exhibiting a sigmoidal curve. Only 60% of the haemolytic activity was retained after treament with heat and proteolytic enzyme. The extract was devoid of hydrolytic enzymes normally present in venoms except for phospholipase A activity, which resulted in the hydrolysis of membrane phospholipids with concomittant appearance of their lyso-derivatives.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  13. Yusuf I, Ahmad SA, Phang LY, Syed MA, Shamaan NA, Abdul Khalil K, et al.
    J Environ Manage, 2016 Dec 01;183:182-95.
    PMID: 27591845 DOI: 10.1016/j.jenvman.2016.08.059
    Biodegradation of agricultural wastes, generated annually from poultry farms and slaughterhouses, can solve the pollution problem and at the same time yield valuable degradation products. But these wastes also constitute environmental nuisance, especially in Malaysia where their illegal disposal on heavy metal contaminated soils poses a serious biodegradation issue as feather tends to accumulate heavy metals from the surrounding environment. Further, continuous use of feather wastes as cheap biosorbent material for the removal of heavy metals from effluents has contributed to the rising amount of polluted feathers, which has necessitated the search for heavy metal-tolerant feather degrading strains. Isolation, characterization and application of a novel heavy metal-tolerant feather-degrading bacterium, identified by 16S RNA sequencing as Alcaligenes sp. AQ05-001 in degradation of heavy metal polluted recalcitrant agricultural wastes, have been reported. Physico-cultural conditions influencing its activities were studied using one-factor-at-a-time and a statistical optimisation approach. Complete degradation of 5 g/L feather was achieved with pH 8, 2% inoculum at 27 °C and incubation period of 36 h. The medium optimisation after the response surface methodology (RSM) resulted in a 10-fold increase in keratinase production (88.4 U/mL) over the initial 8.85 U/mL when supplemented with 0.5% (w/v) sucrose, 0.15% (w/v) ammonium bicarbonate, 0.3% (w/v) skim milk, and 0.01% (w/v) urea. Under optimum conditions, the bacterium was able to degrade heavy metal polluted feathers completely and produced valuable keratinase and protein-rich hydrolysates. About 83% of the feathers polluted with a mixture of highly toxic metals were degraded with high keratinase activities. The heavy metal tolerance ability of this bacterium can be harnessed not only in keratinase production but also in the bioremediation of heavy metal-polluted feather wastes.
    Matched MeSH terms: Peptide Hydrolases/metabolism*
  14. Zarei M, Ghanbari R, Tajabadi N, Abdul-Hamid A, Bakar FA, Saari N
    J Food Sci, 2016 Feb;81(2):C341-7.
    PMID: 26720491 DOI: 10.1111/1750-3841.13200
    Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 μM, respectively.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  15. Gan CY, Cheng LH, Azahari B, Easa AM
    Int J Food Sci Nutr, 2009;60 Suppl 7:99-108.
    PMID: 19194813 DOI: 10.1080/09637480802635090
    Cross-linked soy protein isolate (SPI) gels were produced via single-treatment of SPI with microbial transglutaminase (MTG) for 5 h or 24 h, or with ribose for 2 h, or via combined-treatments of SPI with MTG followed by heating with ribose. Assessment of gel strength and solubility concluded that measures which increased protein cross-links resulted in improved gel strength; however, in most cases the digestibility and amino acid content of the gels were reduced. The combined treated gel of SPI/MTG for 24 h/ribose was more easily digested by digestive enzymes and retained higher amounts of amino acids compared with the control Maillard gels of SPI with ribose. MTG consumed lysine and glutamine and reduced the availability of amino acids for the Maillard reaction with ribose. MTG was able to preserve the nutritional value of SPI against the destructive effect of the Maillard reaction and cross-links.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  16. Ghanbari R, Ebrahimpour A, Abdul-Hamid A, Ismail A, Saari N
    Int J Mol Sci, 2012;13(12):16796-811.
    PMID: 23222684 DOI: 10.3390/ijms131216796
    Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  17. Aqeel Y, Siddiqui R, Farooq M, Khan NA
    Exp Parasitol, 2015 Oct;157:170-6.
    PMID: 26297676 DOI: 10.1016/j.exppara.2015.08.007
    Acanthamoeba is an opportunistic protist pathogen that is responsible for serious human and animal infection. Being one of the most frequently isolated protists from the environment, it is likely that it readily encounters microaerophilic environments. For respiration under anaerobic or low oxygen conditions in several amitochondriate protists, decarboxylation of pyruvate is catalyzed by pyruvate ferredoxin oxidoreductase instead of pyruvate dehydrogenase. In support, Nitazoxanide, an inhibitor of pyruvate ferredoxin oxidoreductase, is effective and non-mutagenic clinically against a range of amitochondriate protists, Giardia intestinalis, Entamoeba histolytica and Trichomonas vaginalis. The overall aim of the present study was to determine in vitro efficacy of Nitazoxanide against Acanthamoeba castellanii. At micromolar concentrations, the findings revealed that Nitazoxanide neither affected A. castellanii growth or viability nor amoeba-mediated host cell monolayer damage in vitro or extracellular proteolytic activities. Similarly, microaerophilic conditions alone had no significant effects. In contrast, microaerophilic conditions together with Nitazoxanide showed amoebicidal effects and inhibited A. castellanii-mediated host cell monolayer damage as well as extracellular proteases. Using encystation assays, it was observed that Nitazoxanide inhibited trophozoite transformation into cysts both under aerophilic and microaerophilic conditions. Furthermore, pre-treatment of cysts with Nitazoxanide inhibited A. castellanii excystation. These findings are important in the identification of potential targets that could be useful against parasite-specific respiration as well as to understand the basic biology of the life cycle of Acanthamoeba.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  18. Chan CL, Yew SM, Ngeow YF, Na SL, Lee KW, Hoh CC, et al.
    BMC Genomics, 2015 Nov 18;16:966.
    PMID: 26581579 DOI: 10.1186/s12864-015-2200-2
    BACKGROUND: Daldinia eschscholtzii is a wood-inhabiting fungus that causes wood decay under certain conditions. It has a broad host range and produces a large repertoire of potentially bioactive compounds. However, there is no extensive genome analysis on this fungal species.

    RESULTS: Two fungal isolates (UM 1400 and UM 1020) from human specimens were identified as Daldinia eschscholtzii by morphological features and ITS-based phylogenetic analysis. Both genomes were similar in size with 10,822 predicted genes in UM 1400 (35.8 Mb) and 11,120 predicted genes in UM 1020 (35.5 Mb). A total of 751 gene families were shared among both UM isolates, including gene families associated with fungus-host interactions. In the CAZyme comparative analysis, both genomes were found to contain arrays of CAZyme related to plant cell wall degradation. Genes encoding secreted peptidases were found in the genomes, which encode for the peptidases involved in the degradation of structural proteins in plant cell wall. In addition, arrays of secondary metabolite backbone genes were identified in both genomes, indicating of their potential to produce bioactive secondary metabolites. Both genomes also contained an abundance of gene encoding signaling components, with three proposed MAPK cascades involved in cell wall integrity, osmoregulation, and mating/filamentation. Besides genomic evidence for degrading capability, both isolates also harbored an array of genes encoding stress response proteins that are potentially significant for adaptation to living in the hostile environments.

    CONCLUSIONS: Our genomic studies provide further information for the biological understanding of the D. eschscholtzii and suggest that these wood-decaying fungi are also equipped for adaptation to adverse environments in the human host.

    Matched MeSH terms: Peptide Hydrolases/metabolism
  19. Tan NH, Ponnudurai G
    Comp. Biochem. Physiol., B, 1990;95(3):577-82.
    PMID: 2158874
    1. The hemorrhagic, procoagulant, anticoagulant, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, arginine ester hydrolase, phospholipase A, L-amino acid oxidase and protease activities of 31 samples of venom from three species of Agkistrodon (A. bilineatus, A. contortrix and A. piscivorus) and 10 venom samples from five other related species belonging to the same tribe of Agkistrodontini were examined. 2. The results indicate that interspecific differences in certain biological activities of the Agkistrodon venoms are more marked than individual variations of the activities, and that these differences can be used for differentiation of the species. Particularly useful for this purpose are the phosphodiesterase, arginine ester hydrolase and anticoagulant activities of the venoms. 3. Venoms of the subspecies of A. contortrix and A. piscivorus do not differ significantly in their biological activities.
    Matched MeSH terms: Peptide Hydrolases/metabolism
  20. Tan NH, Ponnudurai G
    PMID: 1971550
    1. The intravenous median lethal doses (LD50), protease, phosphodiesterase, alkaline phosphomonoesterase, L-amino acid oxidase, acetylcholinesterase, phospholipase A, 5'-nucleotidase, hyauronidase and anticoagulant activities of fourteen samples of venoms from the four common species of krait (Bungarus caeruleus, Bungarus candidus, Bungarus multicinctus and Bungarus fasciatus) were examined. 2. The results indicate that even though there are individual variations in the biological properties of the krait venoms, interspecific differences in the properties can be used for differentiation of the venoms from the four species of Bungarus. Particularly useful for this purpose are the LD50's and the contents of 5'-nucleotidase and hyaluronidase of the venoms.
    Matched MeSH terms: Peptide Hydrolases/metabolism
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