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Iqbal J, Panjwani S, Siddiqui R, Khan NA. Partial characterization of Acanthamoeba castellanii (T4 genotype) DNase activity. Parasitol Res 2014; 114:457-63. [PMID: 25358239 DOI: 10.1007/s00436-014-4203-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/22/2014] [Indexed: 11/28/2022]
Abstract
The deoxyribonuclease (DNase) activities of Acanthamoeba castellanii belonging to the T4 genotype were investigated. Using zymographic assays, the DNase activities had approximate molecular masses of 25 and 35 kDa. A. castellanii DNases exhibited activity at wide-ranging temperature of up to 60 °C and at pH ranging from 4 to 9. The DNases activities were unaffected by proteinase-K treatment, divalent cations such as Ca(++), Cu(++), Mg(++), and Zn(++), or divalent cation chelating agent ethylenediaminetetraacetic acid (EDTA) or sodium dodecyl sulfate (SDS). The non-reliance on divalent cations and homology data suggests that A. castellanii DNases belong to the class of eukaryotic lysosomal DNase II but exhibit robust properties. The DNases activity in A. castellanii interfered with the genomic DNA extraction. Extraction methods involving EDTA, SDS, and proteinase-K resulted in low yield of genomic DNA. On the other hand, these methods resulted in high yield of genomic DNA from human cells suggesting the robust nature of A. castellanii DNases that are unaffected by reagents normally used in blocking eukaryotic DNases. In contrast, the use of chaotropic agent such as guanidine thiocyanate improved the yield of genomic DNA from A. castellanii cells significantly. Further purification and characterization of Acanthamoeba DNases is needed to study their non-classic distinct properties and to determine their role in the biology, cellular differentiation, cell cycle progression, and arrest of Acanthamoeba.
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Affiliation(s)
- Junaid Iqbal
- Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan
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Aqeel Y, Siddiqui R, Khan NA. Silencing of xylose isomerase and cellulose synthase by siRNA inhibits encystation in Acanthamoeba castellanii. Parasitol Res 2012; 112:1221-7. [DOI: 10.1007/s00436-012-3254-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/12/2012] [Indexed: 10/27/2022]
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Rejsek K, Vranova V, Formanek P. Determination of the proportion of total soil extracellular acid phosphomonoesterase (E.C. 3.1.3.2) activity represented by roots in the soil of different forest ecosystems. ScientificWorldJournal 2012; 2012:250805. [PMID: 22701351 PMCID: PMC3373123 DOI: 10.1100/2012/250805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 04/10/2012] [Indexed: 11/17/2022] Open
Abstract
The aim of this study is to present a new method for determining the root-derived extracellular acid phosphomonoesterase (EAPM) activity fraction within the total EAPM activity of soil. EAPM activity was determined for roots, organic and mineral soil. Samples were collected using paired PVC cylinders, inserted to a depth of 15 cm, within seven selected forest stands. Root-derived EAPM formed between 4 and18% of the total EAPM activity of soil from forests of differing maturity. A new approach, presented in this work, enables separation of root-derived EAPM activity from total soil EAPM. Separation of root-derived EAPM from soil provides a better understanding of its role in P-cycling in terrestrial ecosystems. The method presented in this work is a first step towards the separation of root- and microbe-derived EAPM in soils, which are thought to possess different kinetic properties and different sensitivity to environmental change.
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Affiliation(s)
- Klement Rejsek
- Department of Geology and Soil Science, Mendel University in Brno, Zemedelska 3, 61300 Brno, Czech Republic
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4
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Abstract
SUMMARYThe ability of cyst-forming protists such asAcanthamoebato escape death by transforming into a cyst form, that is resistant to harsh physiological, environmental and pharmacological conditions, has continued to pose a serious challenge to human and animal health. A complete understanding of the fundamental principles of genome evolution and biochemical pathways of cellular differentiation offers unprecedented opportunities to counter detrimental outcomes.Acanthamoebacan elude inhospitable conditions by forming cysts. Here we unravel the processes involved in the phenotypic switching ofAcanthamoeba, which are critical in our efforts to find potential targets for chemotherapy.
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SENDO YOSHIHIRO, MATSUSAKA TADAO. Changes in Two Acid Hydrolase Levels During Cyst Differentiation of a Ciliate,Histriculus muscorum1. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1550-7408.1982.tb02894.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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IN MEMORIAM: THOMAS J. BYERS (1935-2003). J Eukaryot Microbiol 2004. [DOI: 10.1111/j.1550-7408.2004.tb00403.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Khunkitti W, Lloyd D, Furr JR, Russell AD. Acanthamoeba castellanii: growth, encystment, excystment and biocide susceptibility. J Infect 1998; 36:43-8. [PMID: 9515667 DOI: 10.1016/s0163-4453(98)93054-7] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Stages in the encystment and excystment processes of Acanthamoeba castellanii have been studied. The kinetics of encystment involved measurements of the three phases (pre-encystment, cyst initiation and cyst wall synthesis). Excystment, starting from a mature cyst, involved pre-emergence, penetration outwards of the cyst wall and free trophozoite. The sensitivity to biocides of trophozoites in the exponential growth phase, pre-encystment trophozoites, mature cysts and pre-excystment cysts has been investigated. Some differences in relative sensitivity to a bisbiguanide (chlorhexidine) and a polymeric biguanide (polyhexamethylene biguanide) were observed, but mature cysts were always the most resistant cellular form.
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Affiliation(s)
- W Khunkitti
- Welsh School of Pharmacy, University of Wales, Cardiff, UK
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Abstract
The lysosomal enzyme N-acetyl-beta-hexosaminidase (beta hex) has been purified from Acanthamoeba castellanii growth medium by a three step procedure. The enzyme was precipitated with ammonium sulfate, partially purified on a DE52 column and purified to homogeneity on an affinity column. The purified beta hex appeared to be a monomer with a molecular mass of 58 kDa and a pI of approximately 5.8. The enzyme activity in growth medium at RT was stable for several months. The purified beta hex was enzymatically deglycosylated and injected into two rabbits to make polyclonal antibodies. One antiserum was specific for beta hex, but the other stained many bands on immunoblots of whole cell preparations. Using fluorescently labelled secondary antibodies we have determined that both antisera stain digestive vacuoles in the Acanthamoeba cytoplasm, and do not stain the contractile vacuole. The multi-specific antiserum had high avidity for beta hex, but also stained the carbohydrate portion of other molecules. These other molecules may be lysosomal enzymes as well, since the activity of several other lysosomal enzymes was partially immunoprecipitable with the antiserum. We plan to use these antibodies to study traffic patterns among the variety of vacuolar structures in Acanthamoeba cytoplasm.
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Affiliation(s)
- K M Baldwin
- Department of Anatomy, Howard University College of Medicine, Washington, DC 20059, USA
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Hugo ER, Byers TJ. S-adenosyl-L-methionine decarboxylase of Acanthamoeba castellanii (Neff): purification and properties. Biochem J 1993; 295 ( Pt 1):203-9. [PMID: 8216217 PMCID: PMC1134839 DOI: 10.1042/bj2950203] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
S-Adenosyl-L-methionine decarboxylase (AdoMetDC) has been purified to near homogeneity from the Neff strain of Acanthamoeba castellanii. The holoenzyme molecular mass is 88.8 kDa, including two copies each of a 32.8 kDa alpha-subunit and a 10-15 kDa beta-subunit. The alpha-subunit contains the active site. It has an N-terminal pyruvoyl group, and the first 19 amino acids are 63 and 74% identical with comparable sequences from yeast and mammals, respectively. The apparent Km for S-adenosylmethionine (AdoMet) in the presence of 2 mM putrescine was 30.0 microM. The enzyme was stimulated 2-fold by putrescine, but was unaffected by spermidine. It was inhibited by the following anti-metabolites, listed with their Ki values: Berenil (0.17 microM), pentamidine (19.4 microM), propamidine (334 microM), hydroxystilbamidine (357 microM), methylglyoxal bis(guanylhydrazone) (604 microM) and ethidium bromide (1.3 mM). Activity of the enzyme fell to undetectable levels during cell differentiation (encystment).
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Affiliation(s)
- E R Hugo
- Department of Molecular Genetics, Ohio State University, Columbus 43210
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Cembella AD, Antia NJ, Harrison PJ. The utilization of inorganic and organic phosphorus compounds as nutrients by eukaryotic microalgae: a multidisciplinary perspective. Part 2. Crit Rev Microbiol 1984; 11:13-81. [PMID: 6373151 DOI: 10.3109/10408418409105902] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Farooqui AA, Hanson WL. Changes in acid phosphatase activity during sporulation of Eimeria tenella oocysts. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1983; 75:185-7. [PMID: 6851483 DOI: 10.1016/0305-0491(83)90059-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Extracts of sporulated oocysts of Eimeria tenella have acid phosphatase activity which can be separated into Peak I (basic form) and Peak II (acidic form) on a DEAE-Sepharose Column. 2. Sporulation markedly effects the behavior of Peak I acid phosphatase (basic form) through the DEAE-Sepharose Column. 3. The Km value of Peak I decreases during sporulation. 4. The data obtained suggest that during sporulation the basic form of acid phosphatase (Peak I) undergoes marked degradation and transformation indicating that acid phosphatases may play an important role in the metabolism of E. tenella.
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Cembella AD, Antia NJ, Harrison PJ. The utilization of inorganic and organic phosphorous compounds as nutrients by eukaryotic microalgae: a multidisciplinary perspective: part 1. Crit Rev Microbiol 1982; 10:317-91. [PMID: 6321101 DOI: 10.3109/10408418209113567] [Citation(s) in RCA: 303] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This comprehensive literature review of the phosphorus nutrition and metabolism of eukaryotic microalgae deals sequentially with (1) extracellular P-compounds available for algal utilization and growth; (2) orthophosphate uptake mechanisms, kinetics, and influence from environmental variables; (3) phosphatase-mediated utilization of organic phosphates involving multiple enzymes, induction and cellular location of repressible and irrepressible phosphatases, and their role in growth physiological processes; (4) intracellular phosphate metabolism covering diversity of phosphometabolites. ATP-linked energy regulation, polyphosphate pools and storage roles, phospholipids and phospholipases; (5) steady-state and transient-state models relating phosphate utilization to growth; (6) ecological aspects covering manifestations of phosphorus limitation, interspecific competition for phosphonutrients among microorganisms, and current views on phosphorus cycling and turnover in aquatic ecosystems. Although concentrating on the microalgae, the review often points out sounder conclusions drawn from bacteria and fungi, and includes specific macroalgae in considering certain subtopics where such algae were better investigated and provided a good basis for comparison with the microalgae.
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Pauls KP, Thompson JE, Lepock JR. Spin label studies of microsomal membranes from Acanthamoeba castellanii in different states of differentiation. Arch Biochem Biophys 1980; 200:22-30. [PMID: 6244789 DOI: 10.1016/0003-9861(80)90325-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Gould WD, Coleman DC, Rubink AJ. Effect of Bacteria and Amoebae on Rhizosphere Phosphatase Activity. Appl Environ Microbiol 1979; 37:943-6. [PMID: 16345390 PMCID: PMC243329 DOI: 10.1128/aem.37.5.943-946.1979] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The contributions of various components of soil microflora and microfauna to rhizosphere phosphatase activity were determined with hydroponic cultures. Three treatments were employed: (i) plants alone (
Bouteloua gracilis
(H.B.K.) Lag. ex Steud.) (ii) plants plus bacteria (
Pseudomonas
sp.), and (iii) plants plus bacteria plus amoebae (
Acanthamoeba
sp.). No alkaline phosphatase was detected, but an appreciable amount of acid phosphatase activity (120 to 500 nmol of
p
-nitrophenylphosphate hydrolyzed per h per plant) was found in the root culture solutions. The presence of bacteria or bacteria and amoebae increased the amount of acid phosphatase in solution, and properties of additional activity were identical to properties of plant acid phosphatase. The presence of bacteria or bacteria and amoebae increased both solution and root phosphatase activities at most initial phosphate concentrations.
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Affiliation(s)
- W D Gould
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, Colorado 80523
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Byers TJ. Growth, reproduction, and differentiation in Acanthamoeba. INTERNATIONAL REVIEW OF CYTOLOGY 1979; 61:283-338. [PMID: 389870 DOI: 10.1016/s0074-7696(08)62000-8] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Seilhamer JJ, Byers TJ. Mutants of Acanthamoeba castellanii resistant to erythromycin, chloramphenicol, and oligomycin. THE JOURNAL OF PROTOZOOLOGY 1978; 25:486-9. [PMID: 739412 DOI: 10.1111/j.1550-7408.1978.tb04172.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cell lines of Acanthamoeba castellanii resistant to erythromycin (EryR), chloramphenicol (CapR), and oligomycin (OliR) have been isolated. These may be the first such mutants for A. castellanii. These mutants have been phenotypically stable for 2 years, surviving storage and vegetative multiplication in the absence of drugs. Resistance was specific for each drug, but double mutants (e.g. EryRCapR) were obtained by stepwise selection. Mutant frequencies were determined in multiwell plates; less than 10 colony forming units (CFU/10(5) amebas were observed in wild-type populations 12 days after incubation in 500 microgram Ery/ml, 2.5 mg Cap/ml, or 15 microgram Oli/ml. After 30 days, averages of 100 CFU/10(5) amebas were observed in Ery and Cap, whereas, frequencies for Oli remained unchanged. Frequencies for EryR and CapR were consistent with rates of recovery from these drugs in batch cultures. We were unable to obtain spontaneous mutants resistant to cycloheximide, emetine, 5-fluorodeoxyuridine, or ethidium bromide. EryR, CapR and OliR could be mitochondria mutants.
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