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The Biosphere
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Secondary, tertiary, and quaternary protein structures are easily changed by a process called denaturation. These changes can be quite damaging. Heating, exposure to acids or bases, and even violent physical action can cause denaturation to occur. The albumin protein in egg white is denatured by heating so that it forms a semisolid mass. Almost the same thing is accomplished by the violent physical action of an egg beater in the preparation of meringue. Heavy metal poisons such as lead and cadmium change the structures of proteins by binding to functional groups on the protein surface.
Nanobiosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
The bioactivity, stability, and quantity of the biological recognition elements immobilized on the electrode are important issues in bioelectrochemistry. Biological activity is a parameter expressing the effects of a molecule on living matter. How does immobilization of biomolecules on naked surfaces of materials differ from that on NP surfaces? The adsorption of biomolecules directly onto naked surfaces of bulk materials frequently results in their denaturation and subsequent loss of bioactivity. Denaturation is a process in which the folding structure of a protein is altered due to exposure to certain chemical or physical factors, e.g., heat, acid, solvents, causing it to become biologically inactive. The AuNPs offer excellent candidates for the immobilization platform. The adsorption of biomolecules onto the surfaces of AuNPs retains their bioactivity and stability because of the biocompatibility and the high surface free energy of AuNPs; biocompatibility is the property of not producing a toxic, injurious, or immunological response to living matter. As compared with flat gold surfaces, AuNPs have a much higher surface area, allowing loading of a larger amount of protein, and are potentially more sensitive. Thus, a number of laboratories have explored the contribution of AuNPs for biomolecular immobilization.
Selection of Operations in Separation Processes
Published in Juan A. Asenjo, Separation Processes in Biotechnology, 2020
Denaturation can be caused by a number of factors, including temperature, extremes of pH, and surface effects. The first two are well known whereas the latter is frequently overlooked and may become a problem when selecting pumps for the large scale. Proteins have both hydrophobic and hydrophilic regions and are surface active; they tend to “spread out” (Asenjo and Patrick, 1990) and denature at accessible interfaces. On air/water interfaces, and when air is finely divided with a large surface area or in violent motion (e.g., in a centrifugal pump), the effect can become very serious. The adsorbed protein may be partially denatured and ultimately revealed as aggregates or as a finely divided precipitate.
Green synthesis of silver nanoparticles using Caesalpinia bonducella leaf extract: characterization and evaluation of in vitro anti-inflammatory and anti-cancer activities
Published in Inorganic and Nano-Metal Chemistry, 2022
In the present study, the anti-inflammatory activity of silver nanoparticles was assessed by protein denaturation method. Protein denaturation is a process in which a protein loses its biological function due to the destruction of its secondary and tertiary structures. This may be brought about by various factors such as heat, electrolytes, pH fluctuation, or alcohol, which produce alterations in the solubility of proteins such as albumins and globulins.[51] Inflammation and protein denaturation are closely related. Protein denaturation leads to inflammation because it permits the generation of autoantigens, which are responsible for inflammation in rheumatic diseases.[52] In the present work, different concentrations of aqueous leaf extract and silver nanoparticles were subjected to evaluation of anti-inflammatory activity which was compared against the standard reference drug diclofenac sodium. A significant difference was observed between the inhibition of thermally induced protein denaturation by the leaf extract and that by the AgNPs when compared against the standard drug (100 µg/mL). The inhibitory effect of silver nanoparticles 85.67 ± 1.63% was comparable to that of diclofenac sodium 91.78 ± 1.46% while the extract showed 20.3 ± 1.45% lesser inhibitory potential compared to both the standard drug and the nanoparticles (Table 1). Our results are in agreement with the reports presented by previous workers where synthesized silver nanoparticles using Calophyllum tomentosum leaf extract and found the anti-inflammatory activity of the nanoparticles to be around 84.64 ± 1.4%.[53]