Structural Insight on the Selectivity of Calyx[4]Arene-Based Inhibitors of MgDependent Atp-Hydrolases.

Located in plasma membranes, ATP hydrolases are involved in several dynamic transport processes, helping to control the movement of ions across cell membranes. ATP hydrolase acts as a transport protein, converting energy from ATP hydrolysis into transport molecules against their concentration gradients. In addition to energy metabolism and active transport, ATP hydrolase is essential for maintaining cellular homeostasis and cell function.

Products of oxidative and non-oxidative metabolism of L-arginine as potential regulators of Ca transport in mitochondria of uterine smooth muscle.

Mitochondria play a crucial role in maintaining Ca homeostasis in cells. Due to the critical regulatory role of the products of oxidative and non-oxidative metabolism of L-arginine, it is essential to clarify their effect on Ca transport in smooth muscle mitochondria. Experiments were performed on the uterine myocytes of rats and isolated mitochondria.

Substitution of bridge carbons for sulphur in calix[4]arene-bis-α-hydroxymethylphosphonic acid transformed mobile carrier into ionic channel accompanied with evoked muscle contraction and impaired neurotransmission powered by membrane action of resulting thiocalix[4]arene-bis-α-hydroxymethylphosphonic acid.

The action of calix[4]arenes C-424, C-425 and C-1193 has been investigated on suspended cholesterol/egg phosphatidylcholine lipid bilayer in a voltage-clamp mode. Comparative analysis with the membrane action by calix[4]arene-bis-α-hydroxymethylphosphonic acid (C-99) has shown that the substitution of bridge carbons for sulphur and addition of another methyl group to two alkyl tales in the lower rim of former dipropoxycalix[4]arene C-99 transformed mobile carrier that C-99 created in lipid bilayer (Shatursky et al., 2014) into a transmembrane pore as exposure of the bilayer membrane to sulphur-containing derivative dibutoxythiocalix[4]arene C-1193 resulted in microscopic transmembrane current patterns indicative of a channel-like mode of facilitated diffusion.

Use of thiacalix[4]arene C-1193 for a directed influence on the functional activity of mitochondria and simulation of this process using a Petri nets.

In molecular biological studies, considerable attention is paid to macrocyclic nanoscale compounds known as calix[4]arenes. An imperative concern in biochemical membranology and molecular biotechnology is the exploration of effectors capable of modifying the intensity of redox reactions within the inner mitochondrial membrane and influencing the activity of its Ca transport systems. The simulation model development is relevant to formalize and generalize the experimental data and assess the conformity of experimental results with theoretical predictions.

Extramitochondrial ATP as [Ca] and cardiolipin content regulator.

An ATP-induced increase of [Ca] in myometrium mitochondria matrix at the absence of exogenous Ca was shown. An ATP-induced increase of Сa efflux from mitochondria ([Сa]) has also been shown. Mitochondria membranes were polarized upon incubation in both Mg- and Mg,ATP-medium.