Purification of the Acetyl CoACarboxylase-1 from Serum of Breast Cancer Women after Mastectomy

Acetyle CoA Carboxylase-1was purified from serum of premenop- ausal women with breast cancer (after Mastectomy or treatment ) by Gel Filtration using Sephadex G-100 and by Ion Exchange using DEAE-Cellulose A-50, also the molecular weight was estimated by the Electrophoresis on Acrylamide in the absence of denaturing elements . The result showed that a single band was obtained at 210 KD by Gel Filtering while Ion Exchange showed one band at 210 KD. The optimum temperature of purified Acetyle CoA Carboxylase-1 was 40 , optimal pH at 7.5 and the optimum substrate concentration at 1.8mM. Michaelis-Menten constant (km) was 0.3mM and Vmax was 23mM.min-1.

Activity of Polyphenoloxidase in red Fuji Apples Promoted with Cationic Surfactant – Role of Surfactant Structure

In this study, we observed the activity of polyphenoloxidase (PPO) in red Fuji apples in the presence of single-chained surfactants (including cetyl trimethyl ammonium bromide (CTAB), and dodecyl trimethyl ammonium bromide (DTAB)) and gemini surfactants (pentamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide), octamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide, dodecamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide), pentamethylene-α,ω-bis(cetyl dimethyl ammonium bromide), and octamethylene-α,ω-bis(cetyl dimethyl ammonium bromide)). It was found that all these surfactants enhanced the activity of PPO in a wide range of temperature at low content. When PPO was denatured by incubating at high temperature, the surfactants caused reactivation of PPO. Compared to the single-chained surfactants, the gemini surfactants increased PPO activity at a much lower concentration. Moreover, the single-chained surfactant and the gemini surfactant acted together to further increase PPO activity, and the synergistic effect reduced the amount of surfactant used. In addition, the Michaelis-Menten constant for PPO did not change in the presence of the surfactants, suggesting the active site should remain well with the surfactants.

Energy Harvesting from Sugarcane Bagasse Juice using Yeast Microbial Fuel Cell Technology

This study demonstrates the feasibility of producing bioelectricity utilizing yeast microbial fuel cell (MFC) technology with sugarcane bagasse juice as a substrate. Yeast Saccharomyces cerevisiae was employed as a bio-catalyst in the production of electrical energy. Sugarcane bagasse juice can be used as a substrate in MFC yeast because of its relatively high sugar content. When yeast was used as a biocatalyst, and Yeast Extract, Peptone, D-Glucose (YPD) Medium was used as a substrate in the MFC in the acclimatization process, current density increased over time to reach 171.43 mA/m2 in closed circuit voltage (CCV), maximum power density (MPD) reached 13.38 mW/m2 after 21 days of the acclimatization process. When using sugarcane bagasse juice as a substrate, MPD reached 6.44 mW/m2 with a sugar concentration of about 5230 ppm. Whereas the sensitivity, maximum current density (Jmax), and apparent Michaelis-Menten constant (𝐾𝑚𝑎𝑝𝑝) from the Michaelis-Menten plot were 0.01474 mA/(m2.ppm), 263.76 mA/m2, and 13594 ppm, respectively. These results indicate that bioelectricity can be produced from sugarcane bagasse juice by Saccharomyces cerevisiae.Keywords: biomass valorization, biofuel cell, acclimatization, maximum power density, Michaelis-Menten constant

The Development of an Amperometric Enzyme Biosensor Based on a Polyaniline-Multiwalled Carbon Nanocomposite for the Detection of a Chemotherapeutic Agent in Serum Samples from Patients

Polyaniline was electrochemically polymerized onto the platinum electrode modified with a mixture of Nafion and multiwalled carbon nanotube (PANI/MWCNT/Nf/Pt) to detect ammonium ion. The nanobiosensor (ASNase/PANI/MWCNT/Nf/Pt) was then prepared by immobilizing L-asparaginase (L-ASNase) on the PANI/MWCNT/Nf nanocomposite. The prepared nanobiosensor was used for the rapid and sensitive detection of serum concentration of the anticancer agent L-asparagine (L-Asp) during chemotherapy. The nanobiosensor has dynamic ranges of zero to 180 μM. The sensitivity of the nanobiosensor was 0.829 μA μM−1 cm−2, and the response time was less than 30 s. The detection limit was 140 nM of L-Asp. The Michaelis–Menten constant ( K m ) was measured to be 36.2 mM. The nanobiosensor was successfully applied for the determination of L-Asp in the blood samples of leukemia patients.

Flexible Enzymatic Glucose Electrochemical Sensor Based on Polystyrene-Gold Electrodes

Metabolic disorders such as the highly prevalent disease diabetes require constant monitoring. The health status of patients is linked to glucose levels in blood, which are typically measured invasively, but can also be correlated to other body fluids such as sweat. Aiming at a reliable glucose biosensor, an enzymatic sensing layer was fabricated on flexible polystyrene foil, for which a versatile nanoimprinting process for microfluidics was presented. For the sensing layer, a gold electrode was modified with a cysteine layer and glutaraldehyde cross-linker for enzyme conformal immobilization. Chronoamperometric measurements were conducted in PBS buffered glucose solution at two potentials (0.65 V and 0.7 V) and demonstrated a linear range between 0.025 mM to 2mM and an operational range of 0.025 mM to 25 mM. The sensitivity was calculated as 1.76µA/mM/cm2 and the limit of detection (LOD) was calculated as 0.055 mM at 0.7 V. An apparent Michaelis–Menten constant of 3.34 mM (0.7 V) and 0.445 mM (0.65 V) was computed. The wide operational range allows the application for point-of-care testing for a variety of body fluids. Yet, the linear range and low LOD make this biosensor especially suitable for non-invasive sweat sensing wearables.

A meta-analysis of effects of CYP2C9 and CYP2C19 polymorphisms on phenytoin pharmacokinetic parameters

Aim: Phenytoin is metabolized through CYP2C9 and CYP2C19 . Polymorphisms of CYP2C9 and CYP2C19 may increase plasma concentration and side effects. Materials & methods: Systematic review and meta-analysis were performed to evaluate the effects of CYP2C9 and CYP2C19 polymorphism on pharmacokinetic parameters. PubMed, Science Direct, Cochrane library, and Thai databases were systematically searched. Results: Eight observational studies, comprising a total of 633 patients were included. Michaelis–Menten constant was significantly higher in the polymorphism of CYP2C9IM/CYP2C19EM and CYP2C9IM/CYP2C19IM groups as compared with the control groups (CYP2C9EM/CYP2C19EM) at 2.16 and 1.55 mg/l (p < 0.00001, p < 0.0001). The maximum rate of action was significantly lower in the control groups as compared with the polymorphism of CYP2C9IM/CYP2C19EM and CYP2C9IM/CYP2C19IM groups at 3.10 and 3.53 mg/kg/day (p = 0.00001, <0.0001). Conclusion: The dosage regimen for patients in the CYP2C9IM group to achieve phenytoin therapeutic levels was 2.1–3.4 mg/kg/day.

Effect of Vernonia amygdalina on phospholipase activity from Naja Mossambica (Cobra)

Background: Phospholipases are one of the numerous enzymes found in the Naja mossambica venom. They play a major role in snakebite envenomation, and also responsible for the hydrolysis of a phospholipid, disrupting the membrane integrity. In this study, we evaluated the effect of Vernonia amygdalina on Phospholipase activity from Naja mossambica (Cobra) Results: Partially purified phospholipase had maximal velocity (Vmax) and Michaelis Menten constant (Km) of 7.6 × 10-5 mol/min and 1.7mg/ml, while the crude phospholipase had Vmax and Km of 9.4 × 10-5mol/min and 2.5mg/ml respectively. Inhibition study of aqueous extracts of Vernonia amygdalina leaf shows that the extract is a potent inhibitor of crude phospholipase in a dose-dependent pattern. The different doses of extract 15 %, 10 % and 5% produced percentage inhibition of 74.04 %, 78.6 % and 86.63% respectively. The kinetic binding constant (Ki) values of crude phospholipase for different concentrations of extracts 5%, 10% and 15% were 0.21mg/ml, 0.29mg/ml and 0.39mg/ml, while the partially purified phospholipase for different concentrations of extracts 5%, 10% and 15% were were 0.48mg/ml, 0.42mg/ml and 0.41mg/ml respectively. It can be deduced from the results that the extract inhibits the phospholipase activity in an uncompetitive manner. Conclusion: Aqueous extract of Vernonia amygdalina leaves may contain some bioactive agents that could serve as potent inhibitors of phospholipase from Naja mossambica venom.

Uptake Kinetics of \({\text{NH}_{4}^{+} }\), \({\text{NO}_{3}^{-} }\) and \({\text{H}_{2}\text{PO}_{4}^{-} }\) by Typha orientalis, Acorus calamus L., Lythrum salicaria L., Sagittaria trifolia L. and Alisma plantago-aquatica Linn

The emergent plants may differ in their capacity to assimilate nutrients from eutrophic water bodies, so the utilization of suitable emergent plants is the key part for successful restoration of shallow eutrophic lakes and rivers. This research applied the depletion method to study the kinetics of uptake of nutrient (H2PO4−, NH4+, NO3−) in different nutrient stresses by the five emergent aquatic plants (Acorus calamus L., Typha orientalis, Lythrum salicaria L., Sagittaria trifolia L., Alisma plantago-aquatica Linn) in the riverine zones of Dashi River (39°30′–39°40′ N, 115°59′–116°5′ E), a shallow eutrophic river located in Fangshan District, Beijing. The results showed that at the three phosphorus levels, A. calamus and A. plantago-aquatica had the highest maximum uptake rate values for NH4+ under low to moderate phosphorus conditions, and high phosphorus, respectively. T. orientalis had the highest maximum uptake rate values for NO3− at all phosphorus concentrations, while the Michaelis-Menten constant values of L. salicaria and A. plantago-aquatica were smaller. At the three nitrogen levels, the maximum uptake rate values for H2PO4− were the greatest for A. plantago-aquatica at the low to moderate nitrogen levels and L. salicaria at high levels. Meanwhile, T. orientalis and L. salicaria had the smallest Michaelis-Menten constant values. In this study, nitrogen microbial transformations, such as nitrification, denitrification and their coupling were not measured and their role in measuring kinetics was not assessed. Thus, achieved results shall be considered as a synthesis of several processes mediated by plants, a theoretical guidance to the selection of plant species for phytoremediation of polluted water bodies with different nutrient stresses for quality improvement around the diverse rivers in Haihe River basin.