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Electroactive Polymers for Drug Delivery
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Adil A. Gobouri, Electroactive Polymeric Materials, 2022
Mehdi Mogharabi-Manzari, Masoud Salehipour, Zahra Pakdin-Parizi, Shahla Rezaei, Roya Khosrokhavar, Ali Motaharian
Several studies reported the determination of glucose by the immobilization of glucose oxidase in conducting polymers matrixes (Wang et al., 2019; Scotto et al., 2020; Al-Sagur et al., 2017). Conducting polymers that contained para- and ortho-quinone groups were used to catalyze the oxidation of glucose via an electrooxidation reaction (Arai et al., 2006). The blood cholesterol level is a vital parameter in clinical diagnostics that might be quantified by amperometric methods using cholesterol oxidase (Cevik et al., 2018). A combination of electrochemistry and immunochemistry concepts could be used in the development of biosensors (Aydın et al., 2020; Shan et al., 2017). Aydin et al. (2018) reported the fabrication of an impedimetric immunosensor for the detection of interleukin 1β by semi-conducting poly(2-thiophen-3-yl-malonic acid) as a matrix for the immobilization of the interleukin 1β antibody.
Fondamental Aspects of Secretory Enzyme Production by Recombinant Microbes
Published in Yoshikatsu Murooka, Tadayuki Imanaka, Recombinant Microbes for Industrial and Agricultural Applications, 2020
Noboru Takizawa, Mitsuo Yamashita, Yoshikatsu Murooka
We have cloned the genes for extracellular cholesterol oxidase (choA) in S. lividans [136,137] and a cytochrome P-450-like protein (choP) [138] from Streptomyces sp. SA-COO, and these two genes have composed an operon. Cholesterol oxidase catalyzes the oxidation of cholesterol to 4-cholesten-3-one, with the reduction of oxygen to hydrogen peroxide. When S. lividans cells carrying the plasmid-cloned choA (pCO-3) were grown in an appropriate medium, the cells produced several times more cholesterol oxidase extracellularly than the original producing strain, Streptomyces sp. SA-COO did [136] (Fig. 8). We also subcloned the gene into the high-copy-number plasmid vectors pSY30 and PIJ702, and these plasmids were then used to transform S. griseus. However, the productivity of the enzyme by S. griseus with either subcloned plasmid was lower than that of S. lividans with pCO-3 [139]. The lower level of production in S. griseus may be a consequence of unknown differences in the transcriptional or translational mechanisms in the host strains S. lividans, S. griseus, and Streptomyces sp. SA-COO.
Biosensors for Food Component Analysis
Published in C. Anandharamakrishnan, S. Parthasarathi, Food Nanotechnology, 2019
Praveena Bhatt, Monali Mukherjee, Uchangi Satyaprasad Akshath
Much like vitamins, cholesterol sensors are important from the point of view of labeling of food products, especially in the health sector. Cholesterol is an important component in food samples like egg yolk, goat meat, dairy products, chicken, beef meat, etc. Today, enzymatic biosensors based on cholesterol oxidase have practically replaced the chemical methods based on the Libermann–Burchard reaction. To fabricate cholesterol biosensors for food analysis, cholesterol oxidase (ChOx) is most commonly used as the biosensing element (Arya et al., 2008). However, cholesterol (total cholesterol) biosensors in food samples are very limited.
Expression and characterization of cholesterol oxidase with high thermal and pH stability from Janthinobacterium agaricidamnosum
Published in Preparative Biochemistry & Biotechnology, 2023
Noriyuki Doukyu, Yuuki Ikehata, Taichi Sasaki
Cholesterol oxidase (COXase, EC 1.1.3.6) is an oxidoreductase containing flavin adenine dinucleotide (FAD) as a redox cofactor. It generally catalyzes the oxidation of the OH group at the C3 position, the isomerization of the double bond between the C5 and C6 positions, and the reduction of oxygen to produce cholest-4-en-3-one (C4E3O) and H2O2.[1,2] However, several COXases oxidize cholesterol to produce 6β-hydroperoxycholest-4-en-3-one (6βHC4E3O) instead of C4E3O.[3,4] COXases have been widely employed to quantify cholesterol content in blood serum for clinical diagnoses.[2] COXases can also be used for pest control due to their pesticidal activity against cotton-eating boll weevil larvae[5] and for the biotransformation of various compounds having 3β-hydroxysteroid structures.[6]Chromobacterium sp. DS-1 COXase alleviates oxysterol cytotoxicity in fibroblasts and thus can have therapeutic applications.[7] Overexpression of Streptomyces gilvosporeus COXase, which serves as a positive regulator of gene expression concerning an antifungal antibiotic, enhances the production of the antibiotic natamycin.[8]
Immobilization of horseradish peroxidase on lysine-functionalized gum Arabic-coated Fe3O4 nanoparticles for cholesterol determination
Published in Preparative Biochemistry & Biotechnology, 2021
Morteza Varamini, Hajar Zamani, Hale Hamedani, Sepide Namdari, Banafsheh Rastegari
The free HRP and HRP@GA-MNPs were studied for their ability to measure cholesterol in the reaction mixture containing cholesterol oxidase using modified method of Immanuel et al..[28] The mixture of 4-AAP (1.7 mM), Phenol (6% w/v), Triton X-100 (5% v/v), or TMB (2 mM), and Cholesterol (0.1 to 10 mM), in the PBS buffer containing 0.6 U mL−1 cholesterol and 15 U mL−1 of free HRP or HRP@GA-MNPs is used for cholesterol assay. Different concentrations of cholesterol were first dissolved in 5% Triton X-100 and DMF and then 50 µL was added to 850 µL of the 4-aminoantipyrine and TMB reaction mixture. The HRP@GA-MNPs containing 5 U HRP were added to the reaction mixture and then, 100 µL of commercial Cholesterol oxidase (ChoX) was added to reach to the final volume of 1 mL.The assay procedure was done for 10 min at 37 °C. The HRP@GA-MNPs were removed using external magnet and the absorbance was recorded by spectrophotometer at wavelength of λmax = 510 and 652 nm, related to 4-AAP and TMB maximum absorbance, respectively. Blank sample was prepared by adding heat inactivated cholesterol oxidase to the above reaction mixture. One Unit of cholesterol oxidase activity was defined as the amount of enzyme that oxidixed 1 μmol of cholesterol and produces H2O2 per time unit (minute) at optimum assay condition.
Cholesterol biosensor based on a plastic optical fibre with sol–gel: structural analysis and sensing properties
Published in Journal of Modern Optics, 2018
D. A. Razo-Medina, M. Trejo-Durán, E. Alvarado-Méndez
To quantify the cholesterol is necessary to produce its oxidation; cholesterol esterase hydrolyzes the cholesterol esters to obtain free cholesterol and fatty acids. The free cholesterol is oxidized in the presence of cholesterol oxidase to give cholestenone with the formation of hydrogen peroxide. A quinoneimine chromogen (red hue, absorption in the visible spectrum (16)) is produced when the hydrogen peroxide reacts with the phenol and 4-aminoantipyrine in the presence of peroxidase. For this reason, we used a LED (633 nm) as light source instead of a laser because the LED is inexpensive, efficient, small and durable.