China
Africa
Explore chapters and articles related to this topic
Contact Urticaria, Dermatitis, and Respiratory Allergy Caused by Enzymes
Published in Ana M. Giménez-Arnau, Howard I. Maibach, Contact Urticaria Syndrome, 2014
Stanciu Monica, Denis Sasseville
Generally not found in animal tissues, β-amylase is present in plant seeds and is produced by bacteria and fungi. Like its close relative α-amylase, it is used in baking as well as in beer brewing and liquor production. Sandiford et al. demonstrated by RAST the allergenicity of β-amylase in barley flour and its potential role in baker’s asthma.[46]
Affinity Modification — Organic Chemistry
Published in Dmitri G. Knorre, Valentin V. Vlassov, Affinity Modification of Biopolymers, 1989
Dmitri G. Knorre, Valentin V. Vlassov
Epoxide groups contain a three-membered oxygen ring of general structure . As well as aziridines, epoxides can react with nucleophilic groups directly or via protonated intermediate formation. They can react at either of the carbon atoms of the ring. An example of an affinity reagent carrying an epoxide group is 2′,3′-epoxypropyl α-d-glucopyranoside100 which readily inactivates soybean β-amylase (EC 3.2.1.2).
The Modification of Cysteine
Published in Roger L. Lundblad, Chemical Reagents for Protein Modification, 2020
Jörnvall and co-workers13 have used reaction with iodoacetate to probe differences in structure in wild-type β-galactosidase and various mutant forms of the enzyme. The modification reactions were performed in 0.1 M Tris, pH 8.1 under nitrogen in the dark. (This condition is of considerable importance since the α-halo acids are photolabile.) The reaction was terminated by the addition of excess β-mercaptoethanol. Kalimi and Love14 have examined the reaction of the hepatic glucorticoid-receptor with iodoacetamide in 0.010 M Tris-0.25 M sucrose. Again, this reaction was performed in the dark. Kallis and Holmgren15 have examined the differences in reactivity of two sulfhydryl groups present at the active site of thioredoxin. The pH dependence of the reaction with iodoacetate suggested that one group had a pKa value of 6.7 while the second was 9.0. Iodoacetamide showed the same pH dependence but the rate of reaction was approximately 20-fold greater than with iodoacetate. For example, at pH 7.2, the second-order rate constant for reaction with iodoacetate was 5.2 M−1 s−1 while it was 107.8 M−1 s−1 for iodoacetamide. The results from this study are shown in Figure 7. The low pK of one of the sulfhydryl groups was suggested to be a reflection of the presence of an adjacent lysine residue. Mikami and co-workers have examined the inactivation of soybean β-amylase with iodoacetamide and iodoacetate.16 Inactivation with iodoacetamide occurred approximately 60 times more rapidly than with iodoacetate at pH 8.6. Hempel and Pietruszko17 have shown that human liver alcohol dehydrogenase is inactivated by iodoacetamide but not by iodoacetic acid. These experiments were performed in 0.030 M sodium phosphate, pH 7.0 containing 0.001 M EDTA.
The eIg technology to generate Ig-like bispecific antibodies
Published in mAbs, 2022
Lennart Kühl, Nadine Aschmoneit, Roland E. Kontermann, Oliver Seifert
Antibodies were analyzed by SDS-PAGE (4 or 6 µg of molecule) and stained with Coomassie-Brilliant Blue G-250. The purity and integrity of molecules (30 µl) were analyzed via SEC using a Waters 2695 HPLC in combination with a TSKgel G2000SWXL (for eFab molecules) or with a TSKgel SuperSW mAb HR column (for all other molecules) (Tosoh Bioscience) at a flow rate of 0.5 ml/min using 0.1 M Na2HPO4/NaH2PO4, 0.1 M Na2SO4, pH 6.7 as mobile phase. Standard proteins: thyroglobulin (669 kDa, RS 8.5 nm), β-amylase (200 kDa, RS 5.4 nm), bovine serum albumin (67 kDa, RS 3.55 nm), carbonic anhydrase (29 kDa, RS 2.35 nm). Stokes radii and molecular weight of analyzed antibodies were interpolated from standard proteins.
A bivalent, bispecific Dab-Fc antibody molecule for dual targeting of HER2 and HER3
Published in mAbs, 2021
Alexander Rau, Katharina Kocher, Mirjam Rommel, Lennart Kühl, Maximilian Albrecht, Hannes Gotthard, Nadine Aschmoneit, Bettina Noll, Monilola A. Olayioye, Roland E. Kontermann, Oliver Seifert
Antibodies were analyzed by SDS-PAGE (4 µg) and stained with Coomassie-Brilliant Blue G-250. Purity and integrity of molecules (9–30 µg in 30 µl) was analyzed via SEC using a Waters 2695 HPLC in combination with a TSKgel SuperSW mAb HR column (822854, Sigma Aldrich) at a flow rate of 0.5 ml/min using 0.1 M Na2HPO4/NaH2PO4, 0.1 M Na2SO4, pH 6.7 as mobile phase. Standard proteins: thyroglobulin (669 kDa, RS 8.5 nm), β-amylase (200 kDa, RS 5.4 nm), bovine serum albumin (67 kDa, RS 3.55 nm), carbonic anhydrase (29 kDa, RS 2.35 nm). Stokes radii of antibodies were interpolated from standard proteins. The determination of the aggregation point of the antibody was performed using dynamic light scattering (ZetaSizer Nano ZS, Malvern). Approximately 100 µg of purified protein was diluted to a total volume of 1 ml and analyzed. The aggregation point was defined as the temperature at which the light scattering increased.
Green and chemically synthesized zinc oxide nanoparticles: effects on in-vitro seedlings and callus cultures of Silybum marianum and evaluation of their antimicrobial and anticancer potential
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Faryal Saeed, Muhammad Younas, Hina Fazal, Sadaf Mushtaq, Faiz ur Rahman, Muzamil Shah, Sumaira Anjum, Nisar Ahmad, Mohammad Ali, Christophe Hano, Bilal Haider Abbasi
Mean root length of control was recorded as 3.5 cm. NP1 showed inhibition of rooting (2.3 cm), which is in accordance with the results of Zafar et al. [32], showing inhibition of seed germination and root length treated with metallic ZnO-NPs and the reason recorded for shorter root length was the direct interaction of NPs with root and its accumulation in root tissues. G-ZNPs showed enhanced rooting and maximum root length was recorded for NP3 (4.3 cm), whereas, NP2 slightly improved the root length (3.7 cm) (Table 1). Similar trend was observed in case of shoot length where maximum shoot length (5.3 cm) was recorded for NP3 (Table 1). Due to enhanced rooting and shooting of seedlings subjected to NP3, it is obvious that maximum FW (220.4 g L−1) and DW (21.23 g L−1) were obtained for NP3 as well (Table 2). These results are similar to the previous report showing the maximum shoot length, root length, FW and DW of sesame seedlings observed in biologically synthesised ZnO-NPs-treated plants [33]. C-ZNPs showed adverse effects on root growth of several plant species like wheat, chickpea, radish, rape and rye grass [34–36]. Zinc is an important micronutrient, crucial for growth and development of plant. ZnO-NPs have been shown to stimulate the biosynthesis of PGRs, especially auxins and gibberellins, which in turn promote the seedling growth as well as length and yield of the plant [37]. Other studies suggest that ZnO-NPs play a key role in activation of enzymes like α- and β-amylase which stimulate metabolic reaction at germination stage [38].