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Nanosensors for Homeland Security
Published in Vinod Kumar Khanna, Nanosensors, 2021
The complexes thus formed flow on and are captured by the protein G on the test line. The protein G is an immunoglobulin G (IgG) antibody–binding protein. The product formed on the test line gives the test signal indicating the presence or absence of F1-antibody or V-antibody in the sample.
Process Design Considerations for Large–Scale Chromatography of Biomolecules
Published in Kenneth E. Avis, Vincent L. Wu, Biotechnology and Biopharmaceutical Manufacturing, Processing, and Preservation, 2020
Richard Wisniewski, Egisto Boschetti, Alois Jungbauer
In order to start a purification process, a resin must be selected. The heuristic rules that can be applied for resin screening are not very advanced. The pragmatic question is: Under what conditions can a particular protein be bound? There also are very pragmatic points to follow, such as long-term availability or whether a drug master file (DMF) is available. At this stage some consideration on productivity should be made. The pragmatic considerations are valid for all types of chromatography. A complete description of all the rules would exceed the scope of this chapter. As an example, a few guidelines for IEX, HIC, affinity chromatography, and hydroxyapatite are discussed. IEX: The isoelectric point (Yang and Langer 1985) of the protein, the salt, the pH of the eluent buffers (Gooding and Schmuck 1983; Kopaciewicz and Regnier 1983), and the protein or peptide molecular weight and stability will determine the resin. The ligand density and porosity of the bead influence the retention time (Wu and Walters 1992) and the loading capacity (Rounds et al. 1986).HIC: The major concern is protein stability and solubility at high salt concentrations. Ligand density considerations may determine at which concentration of the eluent salt the protein is eluted.Affinity chromatography: One should identify if a generic resin is actually available (Protein A, Protein G, T-gel) for antibody purification. For successful metal chelating separation, histidine residues at the surface of the protein should be accessible. The biological nature of the protein should allow it to bind to a certain generic ligand. DNA–binding proteins may bind to dye-affinity resins (Dean and Watson 1979).Hydroxyapatite: Since the binding mechanisms for hydroxyapatite are not well understood, it is very difficult to make a priori considerations about binding. Only literature data, in which a protein from another source has been successfully purified, may be used as an indication of whether to consider this technique. It is necessary to make experiments show whether the protein binds or not (Jungbauer et al. 1989a).
Transesterification of vegetable oils into biodiesel by an immobilized lipase: a review
Published in Biofuels, 2023
Akossi Moya Joëlle Carole, Kouassi Konan Edmond, Abolle Abollé, Kouassi Esaie Kouadio Appiah, Yao Kouassi Benjamin
In ionic bond immobilization, the enzymes are bound by salt bonds [118]. The carriers usually contain ion-exchange residues such as polysaccharides and synthetic polymers [119]. Mendes et al. [120] used Monoaminoethyl-N-aminoethyl (MANAE-agarose) anion exchange resin to immobilize lipase G from Penicillium camembertii. They found that the procedure was quite rapid, and the immobilization step was very fast (within 60 min), resulting in up to 87% protein immobilization, corresponding to 4.52 ± 0.18 mg protein g−1. However, the activity of the enzyme decreased slightly during this immobilization procedure. The ionic binding process is easily achieved and the interactions between the lipase and the support are much stronger than physical adsorption. The ionic binding method, compared to the covalent binding method, can be performed under much milder conditions and, therefore, results in little change in the conformation and active site of the lipase, allowing the enzyme activity to be retained in most cases. However, the binding forces between enzymes and carriers are weaker than those in covalent bonding, and leakage of the enzyme from the carrier may occur in substrate solutions of high ionic strength or with a change in pH [44].
Local ordering and dynamics in anisotropic media by magnetic resonance: from liquid crystals to proteins
Published in Liquid Crystals, 2020
SRLS applied to 15N relaxation from the third immunoglobulin domain of streptococcal protein G (GB3). Experimental 15N T1, T2 and 15N–{1H} NOE relaxation parameters of GB3 were acquired in Reference [91] at magnetic fields of 11.7, 14.1, 16.4 and 18.8 T, in the 278–323 K temperature range. These data had been analysed with the MF method where the global motion of the protein is taken as isotropic, and the local ordering at the site of the probe is taken as axially symmetric. Unsatisfactory statistics were obtained in fitting the experimental data; only by forcing axial global diffusion on the analysis, and allowing the 15N chemical shift anisotropy (CSA) to vary, were adequate statistics obtained [92].
Sources for isolation of extracellular polymeric substances (EPSs) producing bacterial strains which are capable of using wastewater sludge as solo substrate
Published in Environmental Technology, 2019
Viet-Hoang Nguyen, Hong-Khanh Nguyen, Thanh-Dong Nguyen, Tuan-Linh Pham, Cam-Ha Dang-Thi, Yan Song, Rajeshwar Dayal Tyagi
Sludge (suspended solids or SS ∼20 g/L) from beer wastewater treatment plant was used as solo material to grow EPS-producing bacterial strains. Five samples of sludge taken from the same tank on different dates had indigenous EPS concentration ranging from 3615 to 4496 mg/L or 181 to 225 mg EPS/g SS (Table 1). Purified indigenous EPS from sludge contains 0.05–0.10 g carbohydrate/g of LB-EPS, 0.04–0.14 g of carbohydrate/g of TB-EPS and 0.15–0.25 g of protein/g of LB-EPS, 0.05–0.15 g of protein/g of TB-EPS (Figure 1). Aggregation of microorganism in sludge to form bio-flocs is well known due to polymer excreted by the microbial cells [1].