Explore chapters and articles related to this topic
The Biosphere
Published in Stanley E. Manahan, Environmental Chemistry, 2022
The order of amino acids in protein molecules and the resulting three-dimensional structures that form provide an enormous variety of possibilities for protein structure. This is what makes life so diverse. Proteins have primary, secondary, tertiary, and quaternary structures. The structures of protein molecules determine the behavior of proteins in crucial areas such as the processes by which the body's immune system recognizes substances that are foreign to the body. Proteinaceous enzymes depend on their structures for the very specific functions of the enzymes.
Helical Symmetry
Published in Mihai V. Putz, New Frontiers in Nanochemistry, 2020
The biochemical process through a protein structure attains its functional shape or conformation is called protein folding (Dill et al., 2012). The most plausible explanation is the distance-dependence behavior of the conduction, where in the case of shorter homogeneous base sequences the charge transport would be a coherent process, while at longer distances over the aperiodic base sequences the thermally induced hopping is more likely (Giese et al., 2001; Genereux et al., 2011). On the other hand, this special electron structure of the DNA chain could play an important role in detecting DNA damages (Sontz et al., 2012) or could be used as a very efficient spin filter at room temperature for spintronic applications (Göhler et al., 2011). This process is mainly guided by hydrophobic interactions, the formation of intramolecular hydrogen bonds, and van der Waals forces, and it is opposed by conformational entropy (Miller et al., 2014). As a result of this protein folding the most abundant class of secondary structures is the helical configuration, especially the so-called α-helix. The helical structure of the polypeptide chains was for the first time experimentally observed by Pauling et al. (1951), and different forms of the helical configuration can be seen in Figure 21.4.
Formulation of Protein- and Peptide-Based Parenteral Products
Published in Sandeep Nema, John D. Ludwig, Parenteral Medications, 2019
Gaozhong Zhu, Pierre O. Souillac
Denaturation is the process of altering protein structure (i.e., secondary, tertiary, or quaternary structures) from its native folded state. Denaturation may result in an unfolded state, which could further facilitate other physical and chemical degradations. Because a specific structure is required for proteins to exert physiological and pharmacological activities, denaturation causes loss of efficacy and incurs the risk of safety such as immunogenicity.
Using chemical chaperones to increase recombinant human erythropoietin secretion in CHO cell line
Published in Preparative Biochemistry and Biotechnology, 2019
Mehri Mortazavi, Mohammad Ali Shokrgozar, Soroush Sardari, Kayhan Azadmanesh, Reza Mahdian, Hooman Kaghazian, Seyed Nezamedin Hosseini, Mohammad Hossein Hedayati
Chemical chaperones are small molecules that assist molecular chaperones to fold a protein in endoplasmic reticulum also integrate into the protein structure to protect its folding in the secretory pathway. Molecular chaperones and chemical chaperones collaborate with each other to reduce misfolded protein response and enhance protein secretion.[5,15] Such collaboration happens as a result of the increased activity of molecular chaperones after treatment of the cells by chemical chaperone. Also chemical chaperones cooperate with molecular chaperones by adjust their activity.[16] Chemical chaperones are from different groups of components, including polyols such as glycerol, methylamines such as trimethylamine N-oxide (TMAO), sugar, and amino acid derivatives. It is worth mentioning that media optimization is currently the most important plan in recombinant protein production using CHO cell line. The existing challenges in bioprocessing tasks such as low yield and aggregation can be studied and resolved to improve protein production using chemical chaperones through handling molecular chaperones.[3]
Rapid extraction of watermelon seed proteins using microwave and its functional properties
Published in Preparative Biochemistry & Biotechnology, 2021
Manali Behere, Sujata S. Patil, Virendra K. Rathod
Watermelon is one of the essential crops and its fruit pulp is utilized for the preparation of juices, fruit cocktails, and nectars, etc. while “the rind” is used to prepare pectin, pickle, and as a livestock feed, etc. whereas watermelon seeds are reported to be a great source of protein and oil.[2] Several studies have been reported for the extraction of proteins from watermelon seeds. Wani et al. reported the composition of watermelon seed proteins, which involve globulin, glutelin, albumin, and prolamin, as well as studied the functional properties of these proteins, such as dispensability index and digestibility.[3] Furthermore, alkaline extraction and salt assisted extraction of proteins were also studied for watermelon seeds and optimized using surface response methodology to achieve protein recovery of 80.1% with 1:70 (w/v) solute to solvent ratio.[4] Proteins are highly sensitive in nature, and they can undergo conformational changes with reference to the extracting solvent environment. Protein structure is a highly ordered structure wherein its peptide chains are bonded together with hydrogen bonds as well as electrostatic interaction, among others. When molecules of the solvent interact with protein molecules, the charge present on protein molecules gets affected. Any variation in solvent polarity changes the structural protein charge, thereby altering the bonding and folding pattern of the protein and therefore changes its overall conformation.[5,6] Conventional methods like salt and alkaline extraction give less protein recovery with low extraction rate and high solvent consumption.[7] Recently, researchers have reported advanced extraction techniques such as subcritical, ultrasonic, microwave, three phase partitioning, and pressurized liquid for the protein extraction.[8–10] Gadalkar and Rathod reported ultrasound as a process intensifying tool for the alkaline extraction of proteins from watermelon seeds and also examined the amino acid content and functional properties of proteins to check their nutritional value.[11]