A strategy to incorporate prior knowledge into correlation network cutoff selection
NATURE COMMUNICATIONS
Authors: Benedetti, Elisa; Pucic-Bakovic, Maja; Keser, Toma; Gerstner, Nathalie; Bueyuekoezkan, Mustafa; Stambuk, Tamara; Selman, Maurice H. J.; Rudan, Igor; Polasek, Ozren; Hayward, Caroline; Al-Amin, Hassen; Suhre, Karsten; Kastenmueller, Gabi; Lauc, Gordan; Krumsiek, Jan
Abstract
Correlation networks are frequently used to statistically extract biological interactions between omics markers. Network edge selection is typically based on the statistical significance of the correlation coefficients. This procedure, however, is not guaranteed to capture biological mechanisms. We here propose an alternative approach for network reconstruction: a cutoff selection algorithm that maximizes the overlap of the inferred network with available prior knowledge. We first evaluate the approach on IgG glycomics data, for which the biochemical pathway is known and well-characterized. Importantly, even in the case of incomplete or incorrect prior knowledge, the optimal network is close to the true optimum. We then demonstrate the generalizability of the approach with applications to untargeted metabolomics and transcriptomics data. For the transcriptomics case, we demonstrate that the optimized network is superior to statistical networks in systematically retrieving interactions that were not included in the biological reference used for optimization.
Mechanism of the effect of 2, 2 '-azobis (2-amidinopropane) dihydrochloride simulated lipid oxidation on the IgG/IgE binding ability of ovalbumin
FOOD CHEMISTRY
Authors: Zhang, Jing-jing; Tu, Zong-cai; Wang, Hui; Hu, Yue-ming; Du, Peng-cheng; Yang, Yi-peng
Abstract
In this work, the mechanism of the effect of lipid oxidation on the IgG/IgE binding ability of ovalbumin (OVA) was investigated via the peroxyl radicals produced by 2, 2'-azobis (2-amidinopropane) dihydrochloride to simulate lipid oxidation. Results showed that the structure of OVA unfolded partially with an increase in oxidation degree, leading to the exposure of the allergenic epitopes and increasing the IgG/IgE binding ability of OVA. Nine oxidation sites were found on the a-helix, and these sites may unwind the a-helix and expose the allergenic epitopes on the OVA surface, leading to antibody recognition and combination. Consequently, the IgG/IgE binding ability of OVA was increased. In conclusion, the allergenic capacity of OVA can be promoted by modifying peroxyl radical oxidation in processing egg products.