Identification and characterization of phospholipase D in a unicellular red alga (Porphyridium cruentum)

1970 ◽  
Vol 48 (6) ◽  
pp. 643-648 ◽  
Author(s):  
N. J. Antia ◽  
E. Bilinski ◽  
Y. C. Lau
Keyword(s):  
Heavy Metal ◽  
Phospholipase D ◽  
Metal Ion ◽  
Cultured Cells ◽  
Higher Plants ◽  
Sulfhydryl Group ◽  
Red Alga ◽  
Porphyridium Cruentum ◽  
Ph Optimum ◽  
Surface Active Agents

Axenically cultured cells of Porphyridium cruentum were assayed for enzymes catalyzing the hydrolysis of lecithin. The sonicated cells showed virtually exclusive and complete conversion of 14C-choline-labelled lecithin to 14C-choline, with no significant formation of glycerylphosphorylcholine or phosphorylcholine. The enzymatic activity showed a sharp pH optimum at 7.0, and was strongly inhibited by chelating agents (two types), sulfhydryl-group binding reagents (three types), and surface-active agents (anionic and non-ionic). The inhibition from ethylenediamine tetraacetate (EDTA) was reversed by Ca2+ or Sr2+ but not by Mg2+ or Ba2+, and that from —SH binding reagents was reversed by dithiothreitol. Heavy metal ions (Zn2+, Cu2+, Ba2+, Co2+, Mn2+, Fe2+) inhibited the activity, Ca2+ caused stimulation, while Mg2+ and Sr2+ had little effect. The results indicate the occurrence of a pH and heavy-metal ion sensitive, Ca2+-(or Sr2+-) requiring phospholipase D in the red alga, and the involvement of sulfhydryl groups in the expression of its activity. The algal enzyme resembles those from higher plants in its Ca2+ requirement and sensitivity to EDTA and organomercurial sulfhydryl binding reagent, but differs markedly in its optimum pH and several other properties.

scholarly journals Phorbol ester-induced actin cytoskeletal reorganization requires a heavy metal ion.

1991 ◽  
Vol 2 (12) ◽  
pp. 1067-1079 ◽  
Author(s):  
K K Hedberg ◽  
G B Birrell ◽  
O H Griffith
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Phorbol Ester ◽  
Metal Ion ◽  
Cultured Cells ◽  
Transition Metal Ions ◽  
3T3 Cells ◽  
Substrate Protein ◽  
Swiss 3T3

The cell-permeant heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine(TPEN) was found to counteract phorbol ester-induced actin reorganization in PTK2 and Swiss 3T3 cells. By using fluorescence and the higher resolution technique of photoelectron microscopy to monitor actin patterns, 15-min pretreatment with 25-50 microM TPEN was found to dramatically reduce actin alterations resulting from subsequent phorbol ester treatment in PTK2 cells. Similar results were obtained with Swiss 3T3 cells using 50 microM TPEN for 1.5 h. Phorbol ester-induced actin alterations are thought to depend on activation of protein kinase C (PKC). In contrast to the phorbol ester effect, the PKC-independent actin cytoskeletal disruption caused by staurosporine and cytochalasin B was unaffected by TPEN pretreatment. TPEN did not block phorbol ester-induced activation of PKC in Swiss 3T3 cells, as observed by the phosphorylation of the 80K PKC substrate protein (MARCKS protein). TPEN also did not inhibit partially purified PKC from Swiss 3T3 cells in an in vitro PKC-specific commercial assay. To establish that the effect of TPEN is the removal of metal ions and not some other nonspecific effect of TPEN, a series of transition metal ions was added at the end of the TPEN pretreatment. The results indicate that the transient but dramatic phorbol ester-induced reorganization of the actin cytoskeleton in cultured cells depends on an interaction of PKC with a heavy metal, probably zinc.

Use of agro-waste (Musa paradisiaca peels) as a sustainable biosorbent for toxic metal ions removal from contaminated water

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Contact Time ◽  
Metal Ion ◽  
Equilibrium Concentration ◽  
Ion Concentration ◽  
Contaminated Water ◽  
Musa Paradisiaca ◽  
Percentage Removal ◽  
Adsorbent Dose

A study of removal of heavy metal ions from heavy metal contaminated water using agro-waste was carried out with Musa paradisiaca peels as test adsorbent. The study was carried by adding known quantities of lead (II) ions and cadmium (II) ions each and respectively into specific volume of water and adding specific dose of the test adsorbent into the heavy metal ion solution, and the mixture was agitated for a specific period of time and then the concentration of the metal ion remaining in the solution was determined with Perkin Elmer Atomic absorption spectrophotometer model 2380. The effect of contact time, initial adsorbate concentration, adsorbent dose, pH and temperature were considered. From the effect of contact time results equilibrium concentration was established at 60minutes. The percentage removal of these metal ions studied, were all above 90%. Adsorption and percentage removal of Pb2+ and Cd2+ from their aqueous solutions were affected by change in initial metal ion concentration, adsorbent dose pH and temperature. Adsorption isotherm studies confirmed the adsorption of the metal ions on the test adsorbent with good mathematical fits into Langmuir and Freundlich adsorption isotherms. Regression correlation (R2) values of the isotherm plots are all positive (>0.9), which suggests too, that the adsorption fitted into the isotherms considered.

Universal preparation of cellulose-based colorimetric sensor for heavy metal ion detection

2020 ◽  
Vol 236 ◽  
pp. 116037
Author(s):  
Meng Zhang ◽  
Lina Zhang ◽  
Huafeng Tian ◽  
Ang Lu
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Colorimetric Sensor ◽  
Heavy Metal Ion ◽  
Ion Detection ◽  
Metal Ion Detection

Sensitive, portable heavy-metal-ion detection by the sulfidation method on a superhydrophobic concentrator (SPOT)

One Earth ◽  
2021 ◽  
Author(s):  
Hiang Kwee Lee ◽  
Wenxiao Huang ◽  
Yusheng Ye ◽  
Jinwei Xu ◽  
Yucan Peng ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Detection ◽  
Metal Ion Detection

scholarly journals Preparation, characterization and application of CS@PDA@Fe3O4 nanocomposite as a new magnetic nano-adsorber for the removal of metals and dyes in wastewater

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23679-23685
Author(s):  
Xingjing Zhang ◽  
Baohe Li ◽  
Xiaoqian Han ◽  
Nong Wang
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Adsorption ◽  
Metal Ion Adsorption

Synthesis of CS@PDA@Fe3O4 nanocomposite and heavy metal ion adsorption.

scholarly journals The utilization of activated carbon from Jamblang tree bark to adsorb lead heavy metal ion

2021 ◽  
Vol 1087 (1) ◽  
pp. 012062
Author(s):  
Mariana ◽  
F Mulana ◽  
S Muchtar ◽  
A Fadhilah ◽  
C Y Febrina
Keyword(s):  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Tree Bark

Double-side effect of B/C ratio on BDD electrode detection for heavy metal ion in water

2021 ◽  
Vol 771 ◽  
pp. 145430
Author(s):  
Jingxuan Pei ◽  
Xiang Yu ◽  
Songbo Wei ◽  
Rabah Boukherroub ◽  
Yihe Zhang
Keyword(s):  
Heavy Metal ◽  
Side Effect ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Bdd Electrode

scholarly journals Ag-Functionalized Si Nanowire Arrays Aligned Vertically for SERS Detection of Captured Heavy Metal Ions by BSA

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 685
Author(s):  
Ai-Huei Chiou ◽  
Jun-Luo Wei ◽  
Ssu-Han Chen
Keyword(s):  
Heavy Metal ◽  
Raman Scattering ◽  
Metal Ions ◽  
Metal Ion ◽  
Heavy Metal Ions ◽  
Great Promise ◽  
Ag Nps ◽  
Water Contact ◽  
Oh Groups ◽  
Si Nanowire

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. A layer with AgNPs was deposited on the SiNW surface by RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), the observation reveals that the AgNP layer with depths of 30–75 nm was successfully deposited on SiNW arrays. The Ag peaks in EDS and XRD spectra of SiNW arrays confirmed the presence of Ag particles on SiNW arrays. The WCA observations showed a high affinity of the Ag–SiNW arrays immobilized with BSA (water contact angle (WCA) = 87.1°) and ZnSO4 (WCA = 8.8°). The results of FTIR analysis illustrate that the conjugate bonds exist between zinc sulfate (ZnSO4) and –OH groups/–NH groups of BSA. The resulting SiNWs/Ag NPs composite interfaces showed large Raman scattering enhancement for the capture of heavy metal ions by BSA with a detection of 0.1 μM. BSA and ZnSO4 conjugations, illustrating specific SERS spectra with high sensitivity, which suggests great promise in developing label-free biosensors.

scholarly journals A shift in the optimum pH of phospholipase D produced by activating long-chain anions

1969 ◽  
Vol 112 (5) ◽  
pp. 795-799 ◽  
Author(s):  
R. H. Quarles ◽  
R. M. C. Dawson
Keyword(s):  
Phosphatidic Acid ◽  
Phospholipase D ◽  
Activity Profile ◽  
Ph Optimum ◽  
Surface Ph ◽  
Electrophoretic Mobilities ◽  
Low Concentrations ◽  
Optimum Ph ◽  
Long Chain

1. The activity of phospholipase D (phosphatidylcholine phosphatidohydrolase, EC 3.1.4.4) towards ultrasonically treated phosphatidylcholine or large phosphatidylcholine particles activated with ether was maximal near pH5, and there was little activity above pH6. 2. When the enzyme was activated by the addition of phosphatidic acid to large phosphatidylcholine particles the pH optimum was shifted to pH6·5 irrespective of the amount of activator added. 3. When the enzyme was activated with low concentrations of dodecyl sulphate the pH optimum was 5·5 with little activity above pH6. With higher concentrations of dodecyl sulphate the pH–activity profile was shifted upwards towards a pH optimum of 6·5–6·6, the magnitude of the shift depending on the extent of the hydrolysis. 4. The shifts in the pH–activity profiles cannot be correlated with changes in the ‘surface pH’ of the substrate particles calculated from the measurement of their ζ-potentials (electrophoretic mobilities).

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