bioRxiv Science⌕ Search

Biology subjects

Majorina, M. A.

Publications and source records attributed to Majorina, M. A..

2 recordsLinked to original sources

Investigation of ice nucleation properties of Pseudomonas syringae bacterium and insoluble low molecular weight substances

Control of the water freezing process is considerable in different fields of science and technology: from the artificial snow production to the cryopreservation of biological materials. To date, there is no conventional theory that predicts the influence of various biological and non-biological ice nucleators on the formation of ice and, accordingly, on the freezing point of supercooled water. In this work, we investigated the influence of bacterium Pseudomonas syringae, a biological ice nucleator, and heterodisperse insoluble powders of low molecular weight substances on the process of water freezing. AgCl, ZnO and SnO2 were found to be ice nucleators. This property has not been described previously in the literature. It has also been established that insoluble low molecular weight substances affect both the freezing point of water and the temperature of coexistence of water and ice.

biophysics↗

Loops linking secondary structure elements affect the stability of molten globule intermediate state of apomyoglobin

Apomyoglobin is a protein widely used as a model for studying globular protein folding. This work aimed to test the hypothesis on influence of rigidity and length of loops linking protein secondary structure elements on the stability of molten globule intermediate state. For this purpose, we studied folding/unfolding of mutant apomyoglobin forms with substitutions of proline residues to glycine and with loops elongated by three and six glycine residues. For all the protein forms, denaturation/renaturation kinetic curves at different urea concentrations were obtained, folding/unfolding constants were calculated and dependencies of rate constant logarithms on urea concentrations were plotted. All the data gave an opportunity to calculate free energies of different apomyoglobin states. As a result, the mutations in apomyoglobin loops were demonstrated to have a real effect on intermediate state stability compared to unfolded state.

biophysics↗