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Microalgae for Removing Pharmaceutical Compounds from Wastewater
Published in Sreedevi Upadhyayula, Amita Chaudhary, Advanced Materials and Technologies for Wastewater Treatment, 2021
Eliana M. Jimenez-Bambague, Aura C. Ortiz-Escobar, Carlos A. Madera-Parra, Fiderman Machuca-Martinez
Microalgae biodegradation begins with an attack by the enzyme phase I (cytochrome 450). Cytochrome 450 is closely linked to heme-thiolate enzymes that allow the oxidative metabolism of hydrophobic compounds (Zangar et al. 2004). This process makes these compounds more hydrophilic due to the addition or unmasking of the hydroxyl group. Moreover, this process can promote enzymatic reactions such as hydroxylation, carboxylation, oxidation, hydrogenation, glycosylation, demethylation, ring breaking, decarboxylation, dehydroxylation, and bromination (Matamoros et al. 2016; Peng et al. 2014). The enzymes phase II (glutathione-S-transferase) catalyze the conjugation reaction between electrophilic compounds and glutathione. The conjugation of enzyme phase II produces the opening of the epoxide ring for protection against the oxidative damage (Ding et al. 2017).
Mechanisms of chemically induced respiratory toxicities
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
The glutathione S-transferases are a family of multifunctional proteins that have an important role in defending cells against potentially toxic compounds by catalyzing the conjugation of electrophilic metabolites to glutathione. However, detoxication can also be mediated through a non-enzymatic reaction involving binding of the transferases to electrophiles.61,62 In some instances, transferase activity produces an intermediate that is more reactive than the parent compound or the primary metabolite, and therefore conjugation is associated with toxication rather than detoxication.63,64 The transferases are composed of two subunits and exist as either homo- or heterodimeric proteins. They are categorized according to their primary structures into five separate families designated as the classes alpha, mu, pi, sigma and theta. On the basis of decreasing electrophoretic mobilities, three protein bands are resolved and are designated Ya, Yb and Yc.65 Subsequent studies have shown that the Ya and Yc bands represent class alpha, while the Yb band represents class mu.66,67
Role of Computational Tools in Designing Enzymatic Biosensors for the Detection of Pesticides in Environment
Published in Chaudhery Mustansar Hussain, Ajay Kumar Mishra, Nanocomposites for Pollution Control, 2018
Mohd. Shahbaaz, Suvardhan Kanchi, Myalowenkosi Sabela, Krishna Bisetty
Detection of pesticides at the levels established by the Environmental Protection Agency (EPA) remains a challenge. The chromatographic methods coupled to selective detectors have been traditionally used for the analysis of pesticide due to their sensitivity, reliability and efficiency. Nevertheless, chromatographic techniques are time-consuming and laborious, and require expensive equipment and highly trained technicians [20,21]. Over the past decade, considerable attention has been given to the development of biosensors for the detection of pesticides as a promising alternative. Some electrochemical transducers have been used in biosensors for pesticides detection due to their high sensitivity [22–24]. Additionally, their low cost, simple design and small size makes them excellent candidates for the development of portable biosensors [25–28]. Acetylcholinesterase (ACH) is a neurotransmitter and easily undergoes hydrolysis to form choline and acetic acid. It is found at neuromuscular junctions and cholinergic synapses in the central nervous system, where its activity/concentration terminates synaptic transmission [29]. Cytochrome P450 (CYP) is a heme enzyme which enhances the different chemical reactions including heteroatom oxidation, epoxidation and hydroxylation. CYP enzyme is mainly involved in the metabolism of several drugs and xenobiotics for bioactivation [30]. Glutathione S-transferase (GST) is a detoxification enzyme, catalyzing glutathione (GSH) conjugation reactions. Protein phosphorylation process is the predominant molecular mechanism that can be achieved with Protein kinase C (PKC) [31].
Effects of acute arsenic exposure in two different populations of Hyalella curvispina amphipods from North Patagonia Argentina
Published in Journal of Toxicology and Environmental Health, Part A, 2022
Eva R. Kirilovsky, Olga L. Anguiano, Guillermina A. Bongiovanni, Ana Ferrari
One of the recognized mechanisms underlying As-mediated toxicity is its ability to increase the formation of reactive oxygen species (ROS) and reactive nitrogen species, thereby inducing oxidative stress (Flora 2011; Jomova et al. 2011; Wang et al. 2019). Oxidative stress is generated when cellular antioxidant capacity is overwhelmed by reactive species and/or free radicals (Halliwell 2007; Scandalios 2005). Cellular response to a redox imbalance due to a pro-oxidant situation is modulated by compounds like GSH and by antioxidant enzymes. GSH is the most abundant non-protein thiol and participates not only as an antioxidant but also as substrate in many detoxification reactions of As and other toxicants (Minatel et al. 2018; Ventura-Lima, Bogo, and Monserrat 2011). The ubiquitous enzyme catalase (E.C. 1.1.1.6, CAT) is one of the antioxidant enzymes that provides the second tier of defense against ROS toxicity (Sepasi Tehrani and Moosavi-Movahedi 2018). Glutathione S-transferases (EC 2.5.1.18, GST) are detoxifying enzymes which catalyze the conjugation of GSH with diverse compounds including methylated compounds of As (Minatel et al. 2018) and also exert an antioxidant function (Singhal et al. 2015). As exposure has been reported to induce redox imbalance and affect the antioxidant system, by altering CAT and GST activities, in many aquatic organisms including crustaceans (Haque et al. 2018; Jha et al. 2019; Kumar et al. 2019; Lobato et al. 2013; Mardirosian et al. 2015; Ventura-Lima et al. 2009, 2007).
Association of genetic polymorphisms with mercapturic acids in the urine of young healthy subjects before and after exposure to outdoor air pollution
Published in International Journal of Environmental Health Research, 2023
Wenping Song, Lingjie Bian, Mengran Xiong, Yuanyuan Duan, Yi Wang, Xia Zhang, Biao Li, Yulong Dai, Jiawei Lu, Meng Li, Zhiguo Liu, Shigang Liu, Li Zhang, Hongjuan Yao, Rongguang Shao, Guangxi Li, Liang Li
Glutathione S transferase Pi 1 (GSTP1), a widely studied member of the glutathione S transferase (GST) family, has many physiological functions, including metabolism, detoxification and elimination of a variety of carcinogenic compounds and the protection of cells against DNA damage or cancer (Cui et al. 2020). Previous studies have shown that people who smoke tobacco and carry the GSTP1-rs1695 polymorphism are susceptible to lung cancer (Kudhair et al. 2020). Polymorphisms, such as rs1695 and rs1871042, could increase the incidence of asthma by five fold (Joubert et al. 2011). The polymorphisms of rs1695, rs4891, rs749174 and rs762803 showed a significant association with lung cancer susceptibility in smokers (Gu et al. 2014). Prior research suggests that GSTP1 polymorphism may be associated with the detoxification of polycyclic aromatic hydrocarbons and lung cancer susceptibility (Li et al. 2015). Therefore, GSTP1 polymorphisms may be considered a potential biomarker for cancer risk and a prognostic marker for cancer patients (Wang et al. 2015). SPMA is a specific urinary metabolite of benzene, which has been commonly recommended as a urinary biomarker for carcinogenic benzene exposure (Schwedler et al. 2021). Our work hence revealed that the GSTP1 polymorphism represented a significant association with the log2 (Pu1/Po1) of SPMA in urine, indicating that subjects with these SNPs might be prone to be affected in a timely manner by changes in urinary SPMA expression attributed to carcinogenic benzene in airborne ambient conditions. Therefore, the combination of these SNPs and SPMA might be considered a more precise biomarker for the susceptibility and prognosis of lung cancer.
Toxicological and biochemical studies for chlorpyrifos insecticide on some mosquito larvae and their associated predators
Published in Egyptian Journal of Basic and Applied Sciences, 2022
Shaimaa H. Mohammed, Randa I. Eltaly, Hend H. Salem
Glutathione S-transferase (GST) which is dimeric multifunctional enzymes involved in detoxification of a large range of xenobiotics. Elevated GST activity leads to increase resistance of insect to different classes of insecticides [42].