Partial purification and some properties of a neutral sulfhydryl and an acid proteinase from Entamoeba histolytica

1977 ◽  
Vol 23 (4) ◽  
pp. 420-425 ◽  
Author(s):  
John McLaughlin ◽  
Gaetan Faubert
Keyword(s):  
Entamoeba Histolytica ◽  
Cathepsin D ◽  
Metal Ion ◽  
Protozoan Parasite ◽  
Maximum Activity ◽  
Partial Purification ◽  
Acid Proteinase ◽  
Neutral Proteinase ◽  
Optimum Activity ◽  
Serum Albumen

The partial purification of two intracellular proteinases from the protozoan parasite Entamoeba histolytica is reported. One of these enzymes is an acid proteinase exhibiting maximum activity at pH 3.5 (hemoglobin substrate), is little affected by a range of inhibitors or activators, and is presumed to be similar to cathepsin D. Also present is a neutral proteinase exhibiting optimum activity at pH 6.0 (azocasein) but only poorly hydrolyzing either hemoglobin or serum albumen. This latter enzyme displayed no metal ion requirement, but was markedly inhibited by thiol-blocking agents and activated by free sulfhydryl-containing compounds.

Pectolytic and cellulolytic enzymes associated with Helminthosporium leaf spot on Kentucky bluegrass

1972 ◽  
Vol 18 (7) ◽  
pp. 1091-1098 ◽  
Author(s):  
R. R. Muse ◽  
H. B. Couch ◽  
L. D. Moore ◽  
Barbara D. Muse
Keyword(s):  
Carbon Source ◽  
Pectin Methylesterase ◽  
Kentucky Bluegrass ◽  
Maximum Activity ◽  
Partial Purification ◽  
Cellulolytic Enzymes ◽  
Enzyme Preparations ◽  
Optimum Activity ◽  
Culture Filtrates ◽  
Helminthosporium Sativum

Using maceration, viscometric, and spectrophotometric tests, culture filtrates and extracts of healthy and Helminthosporium sativum-infected common and Merion Kentucky bluegrass foliage were tested for pectolytic and cellulolytic enzymes. Culture filtrates, in which pectin was the carbon source, exhibited polymethylgalacturonase and pectin methyl-trans-eliminase activity, with optima of pH 6–7 and pH 8, respectively. Extracts from diseased foliage of common and Merion Kentucky bluegrasses contained pectin methylesterase, optimum activity at pH 7; trans-eliminase, most active at pH 8–9.5; and cellulase (Cx), most active at pH 6. These enzyme activities were always higher in diseased Merion than common Kentucky foliage. Enzyme preparations of diseased common bluegrass also produced polygalacturonase, optimum activity at pH 6, while diseased Merion extracts produced polymethylgalacturonase, with maximum activity at pH 6. Partial purification of the trans-eliminase enzymes indicated they were endopolygalacturonate-trans-eliminases. Extracts of healthy foliage of both varieties contained high pectin methylesterase and low cellulase (Cx) activity.

Scanning electron microscopy of erythrophagocytosis by Entamoeba histolytica trophozoites

1992 ◽  
Vol 50 (1) ◽  
pp. 880-881
Author(s):  
Victor Tsutsumi ◽  
Adolfo Martinez-Palomo ◽  
Kyuichi Tanikawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Red Blood Cells ◽  
Entamoeba Histolytica ◽  
Causative Agent ◽  
Blood Cells ◽  
Protozoan Parasite ◽  
Complex Phenomenon ◽  
Great Capacity ◽  
Scanning Electron

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis in man. The trophozoite or motile form is a highly dynamic and pleomorphic cell with a great capacity to destroy tissues. Moreover, the parasite has the singular ability to phagocytize a variety of different live or death cells. Phagocytosis of red blood cells by E. histolytica trophozoites is a complex phenomenon related with amebic pathogenicity and nutrition.

scholarly journals Partial purification and biochemical characterization of a new highly acidic NYSO laccase from Alcaligenes faecalis

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Soad A. Abdelgalil ◽  
Ahmad R. Attia ◽  
Reyed M. Reyed ◽  
Nadia A. Soliman
Keyword(s):  
Enzyme Activity ◽  
Sodium Dodecyl ◽  
Alcaligenes Faecalis ◽  
Maximum Activity ◽  
Sodium Oxalate ◽  
Partial Purification ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Laccase Enzyme

Abstract Background Due to the multitude industrial applications of ligninolytic enzymes, their demands are increasing. Partial purification and intensive characterization of contemporary highly acidic laccase enzyme produced by an Egyptian local isolate designated Alcaligenes faecalis NYSO were studied in the present investigation. Results Alcaligenes faecalis NYSO laccase has been partially purified and intensively biochemically characterized. It was noticed that 40–60% ammonium sulfate saturation showed maximum activity. A protein band with an apparent molecular mass of ~ 50 kDa related to NYSO laccase was identified through SDS-PAGE and zymography. The partially purified enzyme exhibited maximum activity at 55 °C and pH suboptimal (2.5–5.0). Remarkable activation for enzyme activity was recognized after 10-min exposure to temperatures (T) 50, 60, and 70 °C; time elongation caused inactivation, where ~ 50% of activity was lost after a 7-h exposure to 60 °C. Some metal ions Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Cd2+, Cr2+, and Mg2+ caused strong stimulation for enzyme activity, but Fe2+ and Hg2+ reduced the activity. One millimolar of chelating agents [ethylenediamine tetraacetic acid (EDTA), sodium citrate, and sodium oxalate] caused strong activation for enzyme activity. Sodium dodecyl sulfate (SDS), cysteine-HCl, dithiothreitol (DTT), β-mercaptoethanol, thioglycolic acid, and sodium azide caused strong inhibition for NYSO laccase activity even at low concentration. One millimolar of urea, imidazole, kojic acid, phenylmethylsulfonyl fluoride (PMSF), H2O2, and Triton X-100 caused activation. The partially purified NYSO laccase had decolorization activity towards different dyes such as congo red, crystal violet, methylene blue, fast green, basic fuchsin, bromophenol blue, malachite green, bromocresol purple eriochrome black T, and Coomassie Brilliant Blue R-250 with various degree of degradation. Also, it had a vast range of substrate specificity including lignin, but with high affinity towards p-anisidine. Conclusion The promising properties of the newly studied laccase enzyme from Alcaligenes faecalis NYSO strain would support several industries such as textile, food, and paper and open the possibility for commercial use in water treatment. It will also open the door to new applications due to its ligninolytic properties in the near future.

scholarly journals Localization and Targeting of an Unusual Pyridine Nucleotide Transhydrogenase in Entamoeba histolytica

2010 ◽  
Vol 9 (6) ◽  
pp. 926-933 ◽  
Author(s):  
Mohammad Abu Yousuf ◽  
Fumika Mi-ichi ◽  
Kumiko Nakada-Tsukui ◽  
Tomoyoshi Nozaki
Keyword(s):  
Entamoeba Histolytica ◽  
Fluorescent Protein ◽  
Physiological Role ◽  
Protozoan Parasite ◽  
Pyridine Nucleotide ◽  
Immunofluorescence Assay ◽  
Chemical Degradation ◽  
Content Type ◽  
Targeting Signal ◽  
Pyridine Nucleotide Transhydrogenase

ABSTRACT Pyridine nucleotide transhydrogenase (PNT) catalyzes the direct transfer of a hydride-ion equivalent between NAD(H) and NADP(H) in bacteria and the mitochondria of eukaryotes. PNT was previously postulated to be localized to the highly divergent mitochondrion-related organelle, the mitosome, in the anaerobic/microaerophilic protozoan parasite Entamoeba histolytica based on the potential mitochondrion-targeting signal. However, our previous proteomic study of isolated phagosomes suggested that PNT is localized to organelles other than mitosomes. An immunofluorescence assay using anti-E. histolytica PNT (EhPNT) antibody raised against the NADH-binding domain showed a distribution to the membrane of numerous vesicles/vacuoles, including lysosomes and phagosomes. The domain(s) required for the trafficking of PNT to vesicles/vacuoles was examined by using amoeba transformants expressing a series of carboxyl-terminally truncated PNTs fused with green fluorescent protein or a hemagglutinin tag. All truncated PNTs failed to reach vesicles/vacuoles and were retained in the endoplasmic reticulum. These data indicate that the putative targeting signal is not sufficient for the trafficking of PNT to the vesicular/vacuolar compartments and that full-length PNT is necessary for correct transport. PNT displayed a smear of >120 kDa on SDS-PAGE gels. PNGase F and tunicamycin treatment, chemical degradation of carbohydrates, and heat treatment of PNT suggested that the apparent aberrant mobility of PNT is likely attributable to its hydrophobic nature. PNT that is compartmentalized to the acidic compartments is unprecedented in eukaryotes and may possess a unique physiological role in E. histolytica.

scholarly journals The splicing factor U2AF84 elicits intron retention impacting the virulence of the protozoan parasite Entamoeba histolytica

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Gretter Gonzalez Blanco ◽  
Jesus Valdes Flores ◽  
Maria Cristina Vélez del Valle ◽  
Guillermina García Rivera ◽  
Luis Ortíz Hernández ◽  
...  
Keyword(s):  
Entamoeba Histolytica ◽  
Intron Retention ◽  
Protozoan Parasite ◽  
Splicing Factor
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