Biomedical subjects

M A Batrukova

Publications and source records attributed to M A Batrukova.

6 recordsLinked to original sources

PubMed2000

Ankyrin: structure, properties, and functions.

Recent data on characteristics of the structure, functions, and main properties of ankyrins (proteins that are linkers between the spectrin-based cytoskeleton and integral membrane proteins) are summarized. The interactions of ankyrins with band-3 protein, P-type ATPases, ion channels, receptors, and protein kinase C are considered. The structure of ankyrin repeats that are often contained in other proteins (which are not classified with the ankyrin family) and ensure protein-protein interactions as well as interactions between proteins and nucleic acids is described in details. The mechanisms of regulation of the ability of ankyrins to interact with other proteins (alternative splicing and post-translational modification, including phosphorylation) are also considered.

Animals↗

PubMed1997

Histidine-containing dipeptides as endogenous regulators of the activity of sarcoplasmic reticulum Ca-release channels.

It is shown that histidine-containing dipeptide carnosine (beta-alanyl-L-histidine), which is present in skeletal muscles in millimolar concentrations, decreases the rate of Ca2+ accumulation by the heavy fraction of sarcoplasmic reticulum from rabbit skeletal muscles. This effect results from the ability of carnosine to induce a rapid Ca2+ release from the heavy sarcoplasmic reticulum vesicles via activation of the ruthenium red-sensitive Ca-channels. The effect of carnosine is dose-dependent that indicates the presence of saturable site(s) for carnosine in the molecules of Ca-channels. The C0.5 value carnosine (the concentration that induces the half-maximal Ca2+ release) is 8.7 mM. The 1 N-methylated derivative of carnosine, i.e., anserine, also induces a rapid Ca2+ release with the half-maximal effect at 2.7 mM. Conversely, neither histidine nor beta-alanine (both separately and in the mixture) cause Ca2+ release. In addition, carnosine increases the sensitivity of Ca-channels to their well-known activators (caffeine, AMP, and Ca2+) and decreases inhibitory effect of low concentrations of Mg2+. It is concluded that carnosine as a component of skeletal muscles can be an endogenous regulator of the sarcoplasmic reticulum Ca-channel activity.

Adenosine Monophosphate↗

PubMed1997

Ca-release channels (ryanodine receptors) of sarcoplasmic reticulum: structure and properties. A review.

Recent data on characteristics of the structure, function, and regulation of sarcoplasmic reticulum Ca-release channels (ryanodine receptors) from various types of muscles are summarized. The history of identification and purification of Ca-release channels, the properties of isoforms expressed in various tissues, their electric characteristics, and regulation by endogenous and exogenous compounds are described. The phosphorylation of Ca-release channels by protein kinases and their interaction with various intracellular regulatory proteins are discussed. The proposed mechanisms of excitation-contraction coupling and the role of the Ca-release channels in this process are analyzed.

Animals↗

PubMed1994

Thermal uncoupling of the Ca(2+)-transporting ATPase in sarcoplasmic reticulum. Changes in surface properties of light vesicles.

It is known that the light fraction of rabbit skeletal muscle sarcoplasmic reticulum vesicles can release Ca2+ from the intravesicular space, although the Ca(2+)-conductive channels are present only in the heavy fraction of sarcoplasmic reticulum vesicles. To study the possible pathways of the Ca2+ leakage from light vesicles we have used a short-term treatment for 4.5 min at 45 degrees C which quickly decreases the efficiency of Ca(2+)-transporting ATPase operation without any visible effects on the hydrolytic activity of the Ca(2+)-ATPase in the membranes. The treatment of the vesicles decreased the negative membrane surface potential created by the Ca(2+)-ATPase. Comparative titration of control and heat-treated preparations of light sarcoplasmic reticulum vesicles by K+, Na+, Mg2+, and Ca2+ revealed clear differences in their surface properties. The short-term heating resulted in release of Ca2+ from the vesicles previously loaded with 45Ca2+, which indicates an increase in passive membrane permeability to Ca2+. Study of Ca(2+)-ATPase protein arrangement in the membrane indicated that the heat treatment induced protein oligomerization and some of the Ca(2+)-ATPase molecules acquired intermolecular and intramolecular covalent bonds. From these data, we have concluded that the changes in the surface and structure properties of the vesicle membranes after the short-term heat treatment were the result of clustering of the Ca(2+)-ATPase molecules. This protein rearrangement may create channels for calcium leakage from light sarcoplasmic reticulum vesicles.

Animals↗

PubMed1992

[The effect of carnosine on Ca-channels in rabbit skeletal muscle sarcoplasmic reticulum].

Carnosine (beta-alanyl-L-histidine), which is present in millimolar concentrations in skeletal muscles, induces Ca2+ release from the heavy fraction of rabbit skeletal muscle sarcoplasmic reticulum by activation ruthenium red-sensitive Ca-release channels. The effect of carnosine is dose-dependent, which indicates the presence of saturable carnosine-binding sites in the Ca-release channel molecule. The half-maximal Ca2+ release is observed in the presence of 8.7 mM carnosine. At the same time, carnosine addition to the medium increases the affinity of sarcoplasmic reticulum Ca-channels for the Ca-release activators, caffeine and adenine nucleotides. It is concluded that carnosine is an endogenous regulator of skeletal muscle sarcoplasmic reticulum Ca-channels which modulates the affinity of these channels for different ligands.

Adenine Nucleotides↗

PubMed1989

A comparative study of synthetic carnosine analogs as antioxidants.

1. The antioxidative activity of carnosine and 16 related compounds, both synthetic and natural, was determined. 2. The antioxidative effect was estimated by the ability of the dipeptides to prevent MDA accumulation in the course of LPO induced in rabbit sarcoplasmic reticulum membranes by the Fe2+ ascorbate system. 3. It was found that the antioxidative effect comparable to that of carnosine was exerted by water-soluble (cyclo-L-histidyl-L-proline) and alcohol-soluble (cyclo-L-histidyl-L-phenilalanine) dipeptides as well as by the histidine-free cyclodipeptides (cyclo-L-tyrosyl-L-proline). 4. However, in contrast to its synthetic analogs, carnosine not only inhibited the LPO, but also diminished the level of products accumulated during membrane lipid peroxidation.

Animals↗