A. G. Bobylev

Isoform Composition and Gene Expression of Thick and Thin Filament Proteins in Striated Muscles of Mice after 30-Day Space Flight

Changes in isoform composition, gene expression of titin and nebulin, and isoform composition of myosin heavy chains as well as changes in titin phosphorylation level in skeletal (m. gastrocnemius, m. tibialis anterior, and m. psoas) and cardiac muscles of mice were studied after a 30-day-long space flight onboard the Russian spacecraft “BION-M” number 1. A muscle fibre-type shift from slow-to-fast and a decrease in the content of titin and nebulin in the skeletal muscles of animals from “Flight” group was found. Using Pro-Q Diamond staining, an ~3-fold increase in the phosphorylation level of titin in m. gastrocnemius of mice from the “Flight” group was detected. The content of titin and its phosphorylation level in the cardiac muscle of mice from “Flight” and “Control” groups did not differ; nevertheless an increase (2.2 times) in titin gene expression in the myocardium of flight animals was found. The observed changes are discussed in the context of their role in the contractile activity of striated muscles of mice under conditions of weightlessness.

Impact of biologically relevant anions on reactive oxygen species formation in water under the action of non-ionizing physical agents

The influence of biologically relevant anions (succinate, acetate, citrate, chloride, bicarbonate, hydroorthophosphate, dihydroorthophosphate, nitrite, nitrate) on the formation of hydrogen peroxide and hydroxyl radicals in water was studied under the effect of non-ionizing radiation: heat, laser light with a wavelength of 632.8 nm, corresponding to the maximum absorption of molecular oxygen, and electromagnetic radiation of extremely high frequencies. It has been established that various anions may both inhibit the formation of reactive oxygen species and increase it. Bicarbonate and sulfate anions included in the biological fluids and medicinal mineral waters have significant, but opposite effects on reactive oxygen species production. Different molecular mechanisms of reactive oxygen species formation are considered under the action of the investigated physical factors involving these anions, which may influence the biological processes by signal-regulatory manner and provide a healing effect in physical therapy.

Study of cytotoxicity of fullerene C60 derivatives

We investigated the cytotoxicity of the fullerene C60 derivatives. We showed that complexes of C60 fullerene with polyvinylpyrrolidone (m.w. of polyvinylpyrrolidone 10000 and 25000), C60-NO2-proline and C60-alanine had no toxic effect on HEp-2 cells. Sodium salt of polycarboxylic derivative of fullerene C60 exerted a pronounced toxic effect on this cell culture.

Seasonal changes in isoform composition of giant proteins of thick and thin filaments and titin (connectin) phosphorylation level in striated muscles of bears (Ursidae, Mammalia)

Seasonal changes in the isoform composition of thick and thin filament proteins (titin, myosin heavy chains (MyHCs), nebulin), as well as in the phosphorylation level of titin in striated muscles of brown bear (Ursus arctos) and hibernating Himalayan black bear (Ursus thibetanus ussuricus) were studied. We found that the changes that lead to skeletal muscle atrophy in bears during hibernation are not accompanied by a decrease in the content of nebulin and intact titin-1 (T1) isoforms. However, a decrease (2.1–3.4-fold) in the content of T2 fragments of titin was observed in bear skeletal muscles (m. gastrocnemius, m. longissimus dorsi, m. biceps) during hibernation. The content of the stiffer N2B titin isoform was observed to increase relative to the content of its more compliant N2BA isoform in the left ventricles of hibernating bears. At the same time, in spite of the absence of decrease in the total content of T1 in the myocardium of hibernating brown bear, the content of T2 fragments decreased ∼1.6-fold. The level of titin phosphorylation only slightly increased in the cardiac muscle of hibernating brown bear. In the skeletal muscles of brown bear, the level of titin phosphorylation did not vary between seasons. However, changes in the composition of MyHCs aimed at increasing the content of slow (I) and decreasing the content of fast (IIa) isoforms of this protein during hibernation of brown bear were detected. Content of MyHCs I and IIa in the skeletal muscles of hibernating Himalayan black bear corresponded to that in the skeletal muscles of hibernating brown bear.

Interaction of C 60 Fullerene-Polyvinylpyrrolidone Complex and Brain Aβ(1-42)Peptide in vitro

Using a spectrophotometric method, changes occurring in solution containing brain Aβ(1–42)-peptide, fullerene C60, and polyvinylpyrrolidone were analyzed. Using the Bent-French method, relative binding constants of fullerene C60 with Aβ(1–42)-peptide and polyvinylpyrrolidone with Aβ(1–42)-peptide were determined. These data suggest that Aβ(1–42)-peptide interacting with the C60 fullerene-polyvinylpyrrolidone complex partially displaces polyvinylpyrrolidone and generates a new three molecular compound.

Seasonal changes in the isoform composition of the myosin heavy chains in skeletal muscles of hibernating ground squirrels Spermophilus undulatus

Seasonal changes of the isoform composition of myosin heavy chains in skeletal muscles (m. triceps, m. longissimus dorsi, m. soleus, m. gastrocnemius, m. vastus lateralis) of hibernating ground squirrels Spermophilus undulatus were studied. Functional properties of myosin (the actin-activated ATPase activity and its Ca2+-sensitivity in vitro) were also examined. It was observed that the content of slow myosin heavy chain I isoform increased and the content of fast IIx/d isoform decreased in muscles of torpid ground squirrels and animals which are active in autumn and winter. In muscles of these animals the content of N2A-titin isoform decreased although the relative content of NT-titin isoform, observed in striated muscles of mammals in our previous experimental works, increased. Actin-activated ATPase activity and Ca2+-sensitivity of myosin isolated from skeletal muscles of torpid and interbout ground squirrels were found to reduce. The changes observed are discussed in the context of adaptation of skeletal muscles of ground squirrels to hibernation conditions.

Antiamyloid properties of fullerene C60 derivatives

A comparative estimation of the ability of complexes of fullerene C60 with polyvinylpyrrolidone and fullerene C60 derivatives (the sodium salt of the polycarboxylic derivative of fullerene C60, sodium fullerenolate), has been carried out. The fullerenes destroyed amyloid fibrils of the Aβ(1–42) peptide of the brain and the muscle X-protein. A study of the effect of fullerenes on muscle actin showed that complexes of fullerene C60 with polyvinylpyrrolidone and sodium fullerenolate did not prevent the filament formation of actin, nor did they destroy its filaments in vitro. Conversely, sodium salt of the polycarboxylic derivative of fullerene C60 destroyed actin filaments and prevented their formation. It was concluded that sodium fullerenolate and complexes of fullerene C60 with polyvinylpyrrolidone are the most effective antiamyloid compounds among the fullerenes examined.

Comparative studies of amyloid properties of muscles proteins and brain Aβ-peptides and identification of approaches to destruction of their amyloids in vitro

In this review our data on the comparative study of amyloid properties of titin family proteins and brain Aβ-peptides are represented. Approaches to the destruction of amyloid fibrils of muscle X-protein and brain Aβ(1–42)-peptides by various chemical compounds are also described.

The Effect of Dilution on the Aggregation of Polycarboxylated C 60 Fullerene Nanoparticles

The effect of dilution on the aggregation of nanoparticles of a polycarboxylated derivative of the fullerene C60 has been investigated. The relative abundance of the aggregates decreased and that of individual molecules increased as the concentration of the fullerene in the aqueous phase decreased; this may affect the biological activity of the compound assessed on a “per molecule” basis. Addition of various organic and inorganic salts to the system induced intense disaggregation of the fullerene derivative. The data obtained provide an explanation of the nonstoichiometric character of neutralization of reactive oxygen species by fullerenes, as well as a new interpretation of the physical meaning of studies devoted to the effect of nanoparticles at ultralow concentrations on biological objects.

On functional amyloids of muscle proteins of titin family

In this review, basic characteristics of amyloidoses, conformational diseases of human and animals are given. Properties of amyloids formed by titin family proteins and their possible functional role are discussed by example of mammal hibernation.