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Isolation, Fractionation, and Analysis of Nonhistone Chromosomal Proteins
Published in Lubomir S. Hnilica, Chromosomal Nonhistone Proteins, 2018
Leokadia Klyszejko-Stefanowicz, Lubomir S. Hnilica
First attempts to fractionate the NHCP by hydrophobic chromatography were made by Kikuchi and Sato.100 During studies252 on the interaction of daunomycin with rat liver chromatin these authors noticed that daunomycin binds not only to DNA but also to nonhistone proteins. It was shown, by equilibrium dialysis, that NHCP were by far more potent in binding daunomycin than other proteins tested (histones, phosvitin, casein, catalase, and fibrinogen). The amount of daunomycin bound to NHCP increased with increasing concentration of protein until a maximum was reached, which was most likely due to aggregation of NHCP at high concentrations.249 In an attempt to prevent this aggregation and to increase the daunomycin binding various glycerol concentrations were added to the dialysis buffer.100 It was found that 8% glycerol was inhibitory. This pointed to hydrophobic interactions. Because of the marked interactions between daunomycin and DNA,444 the NHCP were tested for possible DNA contamination.100 DNase treatment had no significant effect on the daunomycin binding indicating that DNA contamination, if any, was negligible. (DNase digested DNA did not react with the drug.444)
Egg Allergy
Published in Andreas L. Lopata, Food Allergy, 2017
Paul J. Turner, Dianne E. Campbell
Other potential allergens within egg yolk include apovitellenins I and VI and phosvitin, with 25% of 40 egg-allergic children demonstrating IgE to these proteins in one report (Walsh et al. 2005). However, these ‘minor’ yolk allergens remain poorly investigated, and it is difficult to draw conclusions as to the relative importance of these allergens.
Food Allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2014
Several studies have identified the major chicken egg allergens [23,24]. Ovomucoid, (Gal d 1), a glycoprotein with a molecular weight of 28 kDa and an acidic isoelectric point, is the major egg allergen. In a study of 18 children with egg allergy, ovomucoid was a more potent allergen than purified ovalbumin as determined by skin prick and in vitro specific IgE tests [25]. While previous studies indicated that ovalbumin was the major egg allergen, this work demonstrated ovomucoid contamination of the ovalbumin accounted for the discrepancy. Ovalbumin (Gal d 2) is a monomeric phospho-glycoprotein with a molecular weight of 43–45 kDa and an acidic isoelectric point. Purified ovalbumin has three primary variants, A1, A2, and A3. It is difficult to determine the exact role of Gal d 2 because of ovomucoid contamination of ovalbumin [25]. Ovotransferrin (Gal d 3), or conalbumin, has a molecular weight of 77 kDa, an acidic isoelectric point, antimicrobial activity, and iron-binding properties. Lysozyme (Gal d 4) is a lower molecular weight allergen (14.3 kDa), which in some studies appears to be a major allergen but in other studies is a minor allergen. Other minor allergens in eggs include apovitellin, ovomucin, and phosvitin. The carbohydrate portion of the glycoproteins in eggs, particularly in ovomucoid, does not play a primary role in specific IgE binding.
The Effects of Ovalbumin on Proliferation, Migration, and Stemness Properties of Chemoresistant SW480 Colon Cancer Cells
Published in Nutrition and Cancer, 2022
Hadi Monji, Hamid Zand, Arman Ghorbani, Katayoun Pourvali
We showed that OVA (8 and 12 mg/ml) inhibited cell proliferation and induced cell cycle arrest in SW480 cells and 5FU-resistance counterparts (Figure 2). Similarly, the induction of cell cycle arrest and apoptosis by hen egg peptides has been demonstrated in other researches, too (18, 20, 22). Jung et al. indicated that cell viability was reduced markedly in melanoma cells treated with 1 mg/mL of phosvitin (27). Regarding the egg white peptides, Ovotransferrin presented high cytotoxicity at 40 mg/mL (23). The proposed mechanism is the induction of caspase 9 and six activity, changing cell morphology and mitochondrial membrane potential, which are apoptosis procedures, thereby inhibiting cancer growth (22). Oguro et al. (28) also indicated that ovomucin possesses an anticancer effect and decreased tumor growth in mice.