Publications by authors named "A A Sobko"

The Rey Auditory Verbal Learning Test (RAVLT) is a classic test used to assess episodic verbal memory in research and clinical practice. We aimed to adapt the RAVLT materials into Russian, provide performance norms across the adult lifespan for the Russian adaptation, and develop a mobile application for automated RAVLT administration across languages. We created three psycholinguistically matched alternative versions of the RAVLT materials in Russian and incorporated them into a new tablet application.

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In a previous study, we characterized Dictyostelium SUMO targeted ubiquitin ligase (StUbL) MIP1 that associates with protein kinase MEK1 and targets SUMOylated MEK1 to ubiquitination (Sobko et al., 2002). These modifications happen in response to activation of MEK1 by the chemoattractant cAMP.

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Introducing a charged group near the N-terminus of gramicidin A (gA) is supposed to suppress its ability to form ion channels by restricting its head-to-head dimerization. The present study dealt with the activity of [Lys1]gA, [Lys3]gA, [Glu1]gA, [Glu3]gA, [Lys2]gA, and [Lys5]gA in model membrane systems (planar lipid bilayers and liposomes) and erythrocytes. In contrast to the Glu-substituted peptides, the lysine derivatives of gA caused non-specific liposomal leakage monitored by fluorescence dequenching of lipid vesicles loaded with carboxyfluorescein or other fluorescent dyes.

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A limited decrease in mitochondrial membrane potential can be beneficial for cells, especially under some pathological conditions, suggesting that mild uncouplers (protonophores) causing such an effect are promising candidates for therapeutic uses. The great majority of protonophores are weak acids capable of permeating across membranes in their neutral and anionic forms. In the present study, protonophorous activity of a series of derivatives of cationic rhodamine 19, including dodecylrhodamine (C(12)R1) and its conjugate with plastoquinone (SkQR1), was revealed using a variety of assays.

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The addition of the channel-forming domain of colicin E1 to liposomes elicited the transmembrane diffusion (flip-flop) of lipids concomitant to the release of the fluorescent dye from liposomes. Good correlation was found between kinetic and concentration dependences of the two processes. Both the liposome leakage and the lipid flip-flop were stimulated upon alkalinization of the buffer solution after colicin binding at acidic pH.

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