Noncovalent Interactions of the Eggshell Membrane
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alent Interactions of the Eggshell Membrane V. I. Ivanov-Omskiia and S. G. Yastrebova* a
Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg, 194021 Russia *e-mail: [email protected] Received March 10, 2020; revised June 9, 2020; accepted June 9, 2020
Abstract—The spectrum of IR active noncovalent interactions of the eggshell membrane has been studied, and the energies of these interactions are estimated. The obtained results are compared to data reported previously for various samples of human aortic valve tissues. It is concluded that the eggshell membrane offers a promising analog of the basal layer of the aortic valve that can be used for biophysical experiments in vitro. Keywords: aortic valve stenosis, hydrogen bond, IR spectroscopy. DOI: 10.1134/S1063785020090199
by the method of IR spectroscopy. For this analysis, let us use the IR spectrum of eggshell membrane reported in literature [4] for separating the absorption band of hydroxyl (–OH) groups (see Fig. 1). Protons of these groups are responsible for the formation of H-bonds. The influence of H-bonds on the vibrational frequencies of OH groups in the IR spectra was studied in much detail [5], which can be used for evaluation of the corresponding binding energies. The present work was aimed at estimating the H-bond energy in the eggshell membrane and comparing this value to analogous bond energies in the human aortic valve tissues. This comparison will allow a conclusion to be made on the prospects of using the eggshell membrane as a model of basal membrane of
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Calcification of aortic walls and aortic valve tissues presents considerable problems and can eventually lead to disablement or even a lethal outcome. It should be noted that the development of calcinosis is accompanied by the formation of large deposits of calcinates, i.e., hydroxyapatite [1]. However, the question as to why, despite the large dimensions of calcified regions, the data of X-ray phase analysis correspond to nanodimensional clusters of hydroxyapatite, has remained unanswered. Recently [2], we have explained this phenomenon by showing that hydroxyapatite nanoclusters are formed in nanosized pores of the aortic basal membrane and aortic valve. It should be noted that detailed investigation of the nucleation and subsequent growth of clusters in the basal membrane in vivo is hindered by numerous technical and ethical factors related to a specific feature of gaining information on the growth of clusters in aortic tissues. In view of these circumstances, the possibility of studying methods for retarding, or even reversal, of this process could be provided by the ability of making experiments under laboratory conditions in vitro. In this context, it would be convenient to find a biological model that could be used in experiments for growing nanoclusters in vitro. Neelakandeswari et al. [3] reported the first in vitro synthesis of hydroxyapatite nanoclusters in nanoporous space of the eggshell membrane, where extended nanoclusters were
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