Features of crystallization of multicomponent solutions: dipeptide, its salt and potassium carbonate

Loskutov, A.I.; Lokshin, B.; Sazonova, N.M.; Solis, P.N.; vysotzkij, V.V.; Loskutov, S.A.

Авторы: Loskutov Alexander Ivanovitch, Lokshin Boris, Sazonova Nellya M., Solis Pinargote Nestor, vysotzkij Vladimir Vladimir, Loskutov Sergei Alexander
Журнал: CrystEngComm
Номер: 23
Год издания: 2021
Издательство: Royal Society of Chemistry
Местоположение издательства: United Kingdom
Первая страница: 6427
Последняя страница: 6441
Номер статьи: D1CE00491C
DOI: 10.1039/d1ce00491c
Аннотация: For the first time, all stages of non-equilibrium crystallization of multicomponent peptide solutions havebeen studied in detail, starting with the formation of colloidal dispersions and ending with the growth ofsolid layers. The crystallization of short dipeptide (DPT-0), its potassium salt (DPT-1) and K2CO3 ofaqueous solutions was studied. DPT-0 and DPT-1 form colloidal solutions in which the particles sizedepends on the charge of the DPT molecule. In comparing with DPT-0 in the case of DPT-1 the particlessize doubles and the coalescence of colloidal particles begins with the formation of micron-sizedaggregates. When DPT solutions are applied to solid surfaces, colloidal particles disintegrate. With anexcess of K2CO3, its stratification at the droplet border is observed. Depending on the charge of DPTmolecule (neutral or anion), not only the surface morphology of layers but also their electron energy andchemical structures change. In DPT-1 layers on gold and graphite, unlike DPT-0, in addition to bipolarresistive switching and residual polarization the sharp negative jumps of tunneling current appear. Thereason for this is the K+ ions, which create one-electron traps in the near-electrode region. Of particularinterest is the opposite direction of the residual polarization vector of DPT-1 layers on graphite and gold.The molecular packaging, the structure and morphology of the growing layers are determined by the natureof the substrate-layer interfaces, which create a template for layer growth. Adsorption of DPT-1 leads tothe destruction of salt bridges and a change in the ratio of α-helix and β-sheet structures. On the gold alllayers of DPTs and K2CO3 are composed of globules, the sizes of which are 40-100 nm. On the graphitesurface islands are observed, with the height of 1-2 monolayers and protofibrils with a width of 17-20 nmand a height of 1-2 nm. Increasing layer thickness, protofibrils form mature fibrils. An analysis of all theresults obtained shows that they are determined by the nature of the conformational changes of peptidemolecules in adsorption layers on different substrates, and the structure of the peptide solid layers laidalready at the stage of its adsorption. Various models of adsorption of DPT on different subjects and thepossibility of practical use of the results are considered
Добавил в систему: Локшин Борис Вениаминович

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Features of crystallization of multicomponent solutions: dipeptide, its salt and potassium carbonateстатья

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