Biology subjects

Kovrigina, E. A.

Publications and source records attributed to Kovrigina, E. A..

2 recordsLinked to original sources

bioRxiv2017

Effect of ligands on stability of H-Ras GTPase

The G domain of a small monomeric GTPase Ras contains a nucleotide-binding pocket and a magnesium-binding site essential for the Ras function in cellular signaling. The G domain also has another (allosteric) ion-binding site on the rear surface of the G domain, which function is still unknown. In this paper, we detailed the effect of calcium and magnesium ions on stability of Ras bound to GDP, GTP, and GTP-mimic GppNHp. We revealed that the remote allosteric ion-binding site contributes very significantly to stability of Ras in the GDP-bound conformation, but nearly not at all--when Ras is bound to a GTP mimic. These findings highlight that further studies of the remote ion-binding site are warranted to reveal its role in the Ras function.

biochemistry↗

bioRxiv2017

Detection of domain motion in NADPH-cytochrome P450 oxidoreductase through polarization anisotropy measurements

Conformational transitions between closed and open states in the NADPH-cytochrome P450 oxidoreductase (POR) play a critical role in its electron-transport function. In this study, we determined rotational diffusion coefficients of the EDANS fluorophore attached to the cytosolic POR construct lacking the N-terminal transmembrane region. We identified two dynamic modes, slow and fast, which are interpreted as the rotational diffusion of POR as a whole and the local domain motion, respectively. Timescale of the local rotational diffusion component suggests that it may correspond to the transient opening of the fully oxidized POR structure.

biochemistry↗