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Valorization of Algal Spent Biomass into Valuable Biochemicals and Energy Resource
Published in Sanjeet Mehariya, Shashi Kant Bhatia, Obulisamy Parthiba Karthikeyan, Algal Biorefineries and the Circular Bioeconomy, 2022
Saravanan Vasanthakumar, K Greeshma, Muthu Arumugam
Sekar and Chandramohan (2008) described antitumor, anti-inflammatory, antiviral, antioxidant, and hepatoprotective properties of phycobiliproteins. They also described that amino acids extracted from Chlorococcum humicola exhibit antifungal and antibacterial activity (Bhagavathy et al., 2011). In addition, phycobiliproteins have applications in food and cosmetic colorants (Eriksen, 2008). Most recently, the presence of Selenoprotein T and its structural elucidation, along with transcriptional analysis, was experimentally proved in microalgae Scenedesmus quadricauda (Reshma et al., 2020). Selenoproteins are a family of proteins that have selenocysteine, a non-standard amino acid residue as repeats. Selenoproteins have an important role in skeletal muscle regeneration, oxidative and calcium homeostasis, cell maintenance, thyroid hormone metabolism, and immune responses.
Arsenals of Pharmacotherapeutically Active Proteins and Peptides: Old Wine in a New Bottle
Published in Debarshi Kar Mahapatra, Swati Gokul Talele, Tatiana G. Volova, A. K. Haghi, Biologically Active Natural Products, 2020
Selenocysteine (Sec) is debated to be the 21st amino acid shown in Figure 2.3. The thiol (-SH) group of cysteine is replaced by selenium atom (Se) to form the molecule of selenocysteine. Selenium functions as a trace element in human beings and is a part of selenoproteins. The pKa of selenocysteine is much lower than that cysteine and therefore, selenium atom of the selenocysteine is negatively charged and the thiol group is positively (protonated) at normal physiological pH.
Relation of selenium status to neuro-regeneration after traumatic spinal cord injury
Published in Gary Bañuelos, Zhi-Qing Lin, Dongli Liang, Xue-bin Yin, Selenium Research for Environment and Human Health: Perspectives, Technologies and Advancements, 2019
R.A. Heller, T. Bock, P. Haubruck, J. Seelig, L. Schomburg, P.A. Grützner, B. Biglari, A. Moghaddam
The trace element selenium (Se) is crucial for the biosynthesis of selenoproteins. Both neurodevelopment and the survival of neurons that are subject to stress depend on a regular selenoprotein biosynthesis and sufficient Se supply by selenoprotein P (SELENOP). The expression of neuronal selenoenzymes depends on a sufficiently high Se supply, maintained by SELENOP.
Insights into the mechanisms of arsenic-selenium interactions and the associated toxicity in plants, animals, and humans: A critical review
Published in Critical Reviews in Environmental Science and Technology, 2021
Waqar Ali, Hua Zhang, Muhammad Junaid, Kang Mao, Nan Xu, Chuanyu Chang, Atta Rasool, Muhammad Wajahat Aslam, Jamshed Ali, Zhugen Yang
Selenium is a component of selenoproteins that exhibit a close relationship with redox reactions. Nevertheless, the enzyme thioredoxin reductase (TrxR), along with thioredoxin (Trx), produces an active di-thiol-di-sulfide and oxidoreductase complex, which further increases cytotoxicity (McKenzie, Arthur, & Beckett, 2002; Sun et al., 2014). The system controls cell growth by binding to cell signaling molecules, such as thioredoxin-interacting protein and apoptosis signal-regulating kinase-1, which are essential compounds responsible for cell growth and cell survival (Wallenberg et al., 2010; Yoshioka, Schreiter, & Lee, 2006). Selenium controls or modulates cell signaling pathways via a thiol redox mechanism and participates in cytotoxicity by reducing intracellular Cys. Arsenic and Se not only generate cytotoxicity through ROS but also affect the corresponding genes and proteins (Carlin et al., 2016; Hettick, Canas-Carrell, French, & Klein, 2015; Whanger, 2004).
Se(IV) oxidation by ferrate(VI) and subsequent in-situ removal of selenium species with the reduction products of ferrate(VI): performance and mechanism
Published in Journal of Environmental Science and Health, Part A, 2020
It is well known that selenium (Se) is an important essential micronutrient for animals and humans at low concentrations. Selenium is an indispensable part of selenoproteins and plays an important role in many biological functions, such as DNA synthesis, thyroid hormone formation, fertility, antioxidant defense, and reproduction.[1] However, an increasing selenium concentration as high as 1.4 mg/L has been observed in wastewater sources because of anthropogenic activities such as mining, smelting and industrial effluent and the World Health Organization (WHO) currently holds a provisional guideline value of 40 μg/L as the maximum concentration limit in drinking water.[2,3] So high concentrations of selenium are over-released, the environment would be seriously polluted, and human health would also be subjected to serious risks and harms.[4]
Understanding selenium metabolism in plants and its role as a beneficial element
Published in Critical Reviews in Environmental Science and Technology, 2019
Reshu Chauhan, Surabhi Awasthi, Sudhakar Srivastava, Sanjay Dwivedi, Elizabeth A. H. Pilon-Smits, Om P. Dhankher, Rudra D. Tripathi
In humans, dietary Se is converted to selenocysteine (SeCys), which is regarded as the 21st proteinogenic amino acid, an essential component of 25 different selenoproteins (Pappas, Zoidis, Surai, & Zervas, 2008). The translational incorporation of SeCys into proteins utilizes a specific t-RNA for SeCys that recognizes an opal UGA (stop) codon functioning as a SeCys codon in the presence of a SeCys insertion sequence in the adjacent mRNA (Lobanov, Hatfield, & Gladyshev, 2009). Selenocysteine functions in the catalytic center of several selenoproteins i.e. glutathione peroxidase, thioredoxin reductase, iodothyronine-deiodinases and selenophosphate synthetase. Apart from this specific SeCys insertion mechanism into selenoproteins, SeCys can also be inserted nonspecifically into other proteins, in place of cysteine. The incorporation of SeCys at the active site of enzymes (e.g. in case of methionine-R-sulfoxide reductase) in place of cysteine can alter their catalytic activity and electron donor specificity (Stadtman, 2005). This is thought to contribute to Se toxicity in humans.