scholarly journals Investigation of guanidine hydrochloride induced unfolding of apolipoprotein A-IMilano

2002 ◽  
Vol 16 (3-4) ◽  
pp. 199-206 ◽  
Author(s):  
Malin Suurkuusk ◽  
Dan Hallén
Keyword(s):  
Phosphate Buffer ◽  
Sodium Phosphate ◽  
Guanidine Hydrochloride ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Unfolded Protein ◽  
Sodium Phosphate Buffer ◽  
Apolipoprotein A ◽  
Helical Content ◽  
Sodium Phosphate Buffer Solution

A guanidine hydrochloride (GuHCl) induced unfolding study of apolipoprotein A-IMilano(apo A-IM) has been performed. The unfolding was followed by circular dichroism (CD) measurements at 222 nm and by isothermal titration (ITC) calorimetry at 25°C. In the ITC experiments enthalpies of transfer were determined for apo A-IMfrom aqueous sodium phosphate buffer solution into solutions of different concentrations of GuHCl. The CD data and the ITC data give complementary and consistent results of the complex unfolding process. Analytical ultracentrifugation experiments were made on apo A-IMin sodium phosphate buffer and in 0.6 M GuHCl, respectively. Analyses of the obtained sedimentation velocity data show that apo A-IMis highly aggregated in sodium phosphate buffer. The aggregates are almost completely dissociated in 0.6 M GuHCl. Aggregation of the protein in sodium phosphate buffer solution induces an increase in α-helical content. The loss of α-helical secondary structural element of the protein upon dissociation of the aggregates destabilises the protein resulting in a low GuHCl concentration of unfolding, [GuHCl]m=1.1 M. The unfolded protein has a significant α-helical content at the unfolded state. From ITC- and CD data we suggest that increased binding of GuHCl to the unfolded protein results in a disruption of the residual secondary structure.

scholarly journals Crosslinking Efficacy and Cytotoxicity of Genipin and Its Activated Form Prepared by Warming It in a Phosphate Buffer: A Comparative Study

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6600
Author(s):  
Takeya Kawamura ◽  
Shunji Yunoki ◽  
Yoshimi Ohyabu ◽  
Toshio Uraoka ◽  
Kazuaki Muramatsu
Keyword(s):  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Mechanical Tests ◽  
Buffer Solution ◽  
Sodium Phosphate Buffer ◽  
In Situ Forming ◽  
Custom Made ◽  
Acute Cytotoxicity ◽  
Sodium Phosphate Buffer Solution

The aim of the present study was to compare the acute and cumulative cytotoxicity of intact (n-GE) and warmed genipin (w-GE), while investigating the differences in crosslinking capabilities of these two genipins by rheological and mechanical tests. The n-GE solution was prepared by dissolving genipin powder in a sodium phosphate buffer solution. The w-GE solution was prepared by warming the n-GE solution at 37 °C for 24 h. The mechanical tests for chitosan (CH)/genipin gels showed the crosslinking rate of w-GE was much greater than that of n-GE up until 6 h after preparation, whereas the degree of crosslinking of CH/n-GE gels became higher at 12 h. The ISO 10993-5 standard method, which is established specifically for evaluating cumulative cytotoxicity, determined equivalent IC50 for w-GE (0.173 mM) and n-GE (0.166 mM). On the other hand, custom-made cytotoxicity tests using a WST-8 assay after 1 h of cultivation showed that the acute cytotoxicity of w-GE was significantly higher than that of n-GE at concentrations between 0.1–5 mM. The acute cytotoxicity of w-GE should be taken into consideration in its practical uses, despite the fact that the much faster crosslinking of w-GE is useful as an effective cross linker for in-situ forming gels.

scholarly journals Effect of combination of electrolyte and buffer on electrical production in fuel cell microbial system with Pseudomonas sp. in molasses substrate

2020 ◽  
Vol 211 ◽  
pp. 03001
Author(s):  
Maswati Baharuddin ◽  
Muh Rajib ◽  
Sappewali ◽  
Ummi Zahra
Keyword(s):  
Electrolyte Solution ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Potassium Phosphate ◽  
Salt Bridge ◽  
High Energy ◽  
Pseudomonas Sp ◽  
Buffer Solution ◽  
Sodium Phosphate Buffer ◽  
Potassium Phosphate Buffer Solution

MFC is a bio-electrochemical system driving an electric current by using high-energy bacteria and oxidants. This research aimed to investigate the effect of electrolyte and buffer on electrical production using Pseudomonas sp. In Molasses substrate. The method in this research was the double compartment that consist of anode and cathode chambers. Both were related by salt bridge. This study showed that the addition of a combination of KMnO4 electrolyte solution with sodium phosphate buffer solution obtained a maximum potential difference of 0.67 V. The result also revealed that the combination of KMnO4 electrolyte solution with Potassium Phosphate Buffer solution produced a 1.44 mA maximum current with power density of 660.82 mW/m2.

scholarly journals Extracting Sweetening and Bioactive Compounds From Stevia Rebaudiana Using Cellulase Enzyme

2021 ◽  
Vol 910 (1) ◽  
pp. 012022
Author(s):  
Dhia F. Al-Fekaiki ◽  
Basair A. Al-Temimi
Keyword(s):  
Bioactive Compounds ◽  
Phosphate Buffer Solution ◽  
Stevia Rebaudiana ◽  
Steviol Glycosides ◽  
Enzyme Extract ◽  
Buffer Solution ◽  
Solution Ph ◽  
E Coli ◽  
Sodium Phosphate Buffer ◽  
Sodium Phosphate Buffer Solution

Abstract This study was conducted to find out the sweetener and bioactive compounds in the Stevia plant’s enzyme extract and its antioxidant and antibacterial effect. The enzyme extract was used in a ratio of 1:15 (w: v) with the use of sodium phosphate buffer solution (pH=4) in an equal mixing ratio with the enzyme. Extraction was carried out at 55°C with a time of 25 minutes to extract and determine steviol glycosides using HPLC. Stevioside and Rebaudioside-A (5.101 and 3.027 mg/g) were obtained, respectively. The study showed that Stevia contains high amounts of phenols and flavonoids (83.052 and 71,765) mg/ml, respectively. The enzyme extract gave an antioxidant activity of 71.367% compared to BHT which gave an activity of 77.267%. It gave the highest inhibitory activity against Bacillus subtilis, which was 14 mm, followed by Staphylococcus aureus and E. coli. The bioactive compounds were diagnosed by GC-MS and contained important bioactive compounds such as Hydroxydehydrostevic acid (steviol), 1,2-Benzenediol, 4-Ethylcatechol, 9-Octadecenamide, (Z)-, Isosteviol methyl ester, gamma-Sitosterol.

Bioceramic Hydroxyapatite Granules for Purification of Biotechnological Products

2011 ◽  
Vol 284-286 ◽  
pp. 1764-1769 ◽  
Author(s):  
Vitalijs Lakevics ◽  
Janis Locs ◽  
Dagnija Loca ◽  
Valentina Stepanova ◽  
Liga Berzina-Cimdina ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Phosphate Buffer ◽  
Bovine Serum ◽  
Phosphate Buffer Solution ◽  
Sorption Process ◽  
Buffer Solution ◽  
Ph Values ◽  
Bovine Serum Albumin Adsorption ◽  
Albumin Adsorption

Sorption experiments of bovine serum albumin (BSA) on hydroxyapatite (HAp) ceramic granules, prepared at three temperatures 900°C, 1000°C and 1150°C were performed at room temperature 18,6 °C and phosphate buffer, pH 5,83; 6.38 and 7,39. Thermal treatment contributed to the decrease of bovine serum albumin immobilization indicating that sorption process depended on HAp ceramics specific surface area and pH values of phosphate buffer solution. However, it was confirmed that granule size was also an important parameter for bovine serum albumin adsorption. As a result of these experiments, the most appropriate adsorption conditions and phosphate buffer pH values influence on to BSA sorption were analyzed.

Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

2000 ◽  
Vol 63 (6) ◽  
pp. 703-708 ◽  
Author(s):  
MARCY A. WISNIEWSKY ◽  
BONITA A. GLATZ ◽  
MARK L. GLEASON ◽  
CHERYLL A. REITMEIER
Keyword(s):  
Escherichia Coli ◽  
Chlorine Dioxide ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Escherichia Coli O157 ◽  
Peroxyacetic Acid ◽  
Water Control ◽  
Buffer Solution ◽  
E Coli ◽  
Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

Effects of sodium phosphate buffer on horseradish peroxidase thermal stability

2008 ◽  
Vol 93 (2) ◽  
pp. 569-574 ◽  
Author(s):  
L. Haifeng ◽  
L. Yuwen ◽  
C. Xiaomin ◽  
W. Zhiyong ◽  
W. Cunxin
Keyword(s):  
Thermal Stability ◽  
Horseradish Peroxidase ◽  
Phosphate Buffer ◽  
Sodium Phosphate ◽  
Sodium Phosphate Buffer

Electrocatalytic performance of a zinc sulphide nanoparticles-modified carbon paste electrode for the simultaneous determination of acetaminophen, guanine and adenine

2018 ◽  
Vol 10 (11) ◽  
pp. 1362-1371 ◽  
Author(s):  
Mallappa Mahanthappa ◽  
Nagaraju Kottam ◽  
Shivaraj Yellappa
Keyword(s):  
Carbon Paste Electrode ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Zinc Sulphide ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Guanine And Adenine ◽  
Paste Electrode

The simultaneous electroanalysis of acetaminophen (AC), guanine (G) and adenine (A) was successfully achieved on the zinc sulphide nanoparticles-modified carbon paste electrode (ZnS NPs/CPE) in phosphate buffer solution (PBS).

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