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Licensed Unlicensed Requires Authentication Published by De Gruyter March 13, 2019

Structural and conformational stability of hemocyanin from the garden snail Cornu aspersum

Aleksandar Dolashki , Lyudmila Velkova EMAIL logo , Wolfgang Voelter and Pavlina Dolashka


Various aspects of biomedical applications of molluscan hemocyanins, associated with their immunogenic properties and antitumor activity, promoted us to perform structural studies on these glycoproteins. The stability and reassociation behavior of native Cornu aspersum hemocyanin (CaH) are studied in the presence of different concentrations of Ca2+ and Mg2+ ions and pH values using electron microscopy. Higher concentrations of those ions led to a more rapid reassociation of CaH, resulting in stable multidecamers with different lengths. The conformational changes of native CaH are investigated within a wide pH-temperature range by UV circular dichroism. The relatively small changes of initial [θ]λ indicated that many secondary structural elements are preserved, even at high temperatures above 80°C, especially at neutral pH. The mechanism of thermal unfolding of CaH has a complicated character, and the process is irreversible. The conformational stability of the native didecameric aggregates of CaH toward various denaturants indicates that hydrophilic and polar forces stabilize the quaternary structure. For the first time, the unfolding of native CaH in water solutions in the presence of four different denaturants is investigated. The free energy of stabilization in water, ∆GDH2O, was calculated in the range of 15.48–16.95 kJ mol−1. The presented results will facilitate the further investigation of the properties and potential applications of CaH.


This work was supported by the research grant Project BG05M2OP001-1.002-0019: “Clean technologies for sustainable environment – water, waste, energy for circular economy” (Clean & Circle), for development of a Centre of Competence and by the Bulgarian Ministry of Education and Science under the National Research Program “BioActivMed” approved by DCM № 658/14.09.2018.


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Received: 2018-06-10
Revised: 2019-01-23
Accepted: 2019-02-02
Published Online: 2019-03-13
Published in Print: 2019-05-27

©2019 Walter de Gruyter GmbH, Berlin/Boston

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