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Biomedical subjects

E E Fesenko

Publications and source records attributed to E E Fesenko.

At least 37 records · Page 2Linked to original sources
PubMed1992

Low molecular mass phosphoproteins from the frog rod outer segments form a complex with 48 kDa protein.

Upon separation of cAMP-dependent low molecular mass phosphoproteins [Components I and II; Polans et al. (1979) J. gen. Physiol. 74, 595-613] from the frog rod outer segments by gel-chromatography, isoelectric focusing, non-denaturating electrophoresis and ion-exchange chromatography, they behave like subunits of the oligomeric complex. Apparent molecular mass of the complex determined by gel-chromatography is 52-57 kDa and by non-denaturating gradient electrophoresis is 62-66 kDa. The isoelectric point of the complex is 5.5. The elution profile of Components I and II upon gel-chromatography and ion-exchange chromatography coincides with that of major rod outer segment 48 kDa protein. The isoelectric point for them also coincides with the isoelectric point of 48 kDa protein. The amount of low molecular mass phosphoproteins is sealed rods is equal to one molecule per 60 rhodopsin molecules and coincides with that of a 48 kDa protein. It is suggested that in solution Components I and II form an oligomeric complex with 48 kDa protein.

Animals↗
PubMed1991

Antiidiotypic antibodies against anti-cGMP polyclonal antibodies.

Affinity-purified polyclonal anti-cGMP antibodies were obtained from rabbit serum after immunization by succinyl derivative of cGMP coupled to bovine serum albumin. These antibodies were used to raise antiidiotypic antibodies in rats. Putative antiidiotypic serum inhibited the binding of [3H]cGMP to affinity-purified anti-cGMP antibodies. The influence of immunoglobulins isolated from antiidiotypic serum on the ion conductance of rod outer segment plasma membrane fragments from frog retina was studied in patch-clamp experiments. These immunoglobulins increased the conductance of ion channels acting like a natural agonist (cGMP). Preimmune immunoglobulins did not act. The data obtained suggest that antiidiotypic antibodies interact with regulatory cGMP-binding sites of the plasma membrane channels.

Animals↗
PubMed1991

Antiidiotypic antibodies interacting with cGMP-dependent channels of frog retinal rod outer segments.

Antiidiotypic approach was used to obtain antibodies interacting with cGMP-binding site of the cGMP-activated channel of the photoreceptor cell. Monoclonal anti-BrcGMP antibodies having characteristics of binding of agonist and its analogs close to those for a natural receptor have been obtained. These antibodies were used to raise polyclonal antiidiotypic antibodies capable of interacting with a natural cGMP-receptor. Application of immunoglobulins, isolated from antiidiotypic serum, to inside-out fragments of the rod plasma membrane led to an irreversible increase of the conductance of cGMP-dependent channels.

Animals↗
PubMed1990

[An analysis of the supramolecular organization of the olfactory neuroepithelium in the rat by freeze etching with rotary platinum-carbon shadow-casting].

The rat olfactory epithelium was analysed by freeze-deep etching and Pt/C rotary replication. Ultrathin sections and freeze-etching findings of proximal (dendrite) and distal (axon) parts of bipolar olfactory neurons are examined. The supramolecular organization of neuron membranes and intracellular cytoskeleton structure is studied. The role of the Schwann cells in formation of isolated axon bundles is discussed. Methods of the whole neuroepithelium preparation for freeze-etching and different easy approaches of obtaining the Pt/C rotary shadowing replicas with high resolution (15-20A) are presented.

Animals↗
PubMed1990

Ionic cyclotron resonance in biomolecules.

The possible mechanism of action of weak electric and magnetic fields of extremely low frequency on biomolecules is discussed in terms of the resonance effects on the precession of the ion orbits in a static magnetic field. The proposed model retains the principal merits of the familiar model of Liboff, but is free from the basic shortcomings of the latter.

Biophysical Phenomena↗
PubMed1989

Regulation of cGMP-dependent conductance in cytoplasmic membrane of rod outer segments by transducin.

A preparation of the photoreceptor G-protein, transducin, containing mainly the T alpha-subunit in a GTP-gamma-S-bound form, has been used for perfusion of the intracellular surface of excised patches of rod outer segment cytoplasmic membrane from frog retina. The preparation has been shown to result in the complete suppression of the cGMP-activated ionic conductance of the cytoplasmic membrane patch. The effect is entirely reversible after the protein has been washed out and is not observed in the absence of cGMP. The degree of conductance inhibition depends on the protein concentration, half-maximal inhibition occurring at 1 microM T alpha-GTP-gamma-S.

Animals↗
PubMed1989

The effect of ATP, GTP and cAMP on the cGMP-dependent conductance of the fragments from frog rod plasma membrane.

Using a 'patch-clamp' method in the 'inside-out' configuration, ATP, ADP, AMP-PCP and AMP-PNP have been shown to increase the cGMP-dependent component of the rod plasma membrane conductance 2-4-fold and GTP, GDP but not GMP or nonhydrolyzable GTP analogs GMP-PNP and GTP-gamma-S to abolish the ATP action. The ATP and GTP effects were observed at [EDTA] = 1 mM when magnesium and calcium ions were absent. In about half of the experiments the cGMP-dependent conductance was shown to be increased by cAMP in the micromolar concentration range by 10-50%, the cAMP action did not depend on the presence of nucleoside triphosphates. In vivo ATP, GTP and cAMP are assumed to modulate the sensitivity of the photoreceptor plasma membrane to cGMP.

Adenine Nucleotides↗
PubMed1988

GTP-binding protein associated with amino acid binding proteins from olfactory epithelium of skate, Dasyatis pastinaca.

Amino acid binding protein (98 kDa) from olfactory epithelium of skate, Dasyatis pastinaca, form a stable complex with the 56 kDa protein. This complex dissociates in the presence of 10 microM GTP gamma S and 2 mM MgCl2. The 56 kDa protein has a steady-state GTPase activity (15 nmol/min per mg). Binding of amino acids to the 98 kDa protein specifically stimulates GTPase activity of the 56 kDa protein; half-maximal stimulation of GTPase activity is observed at 0.1 microM amino acid.

Alanine↗
PubMed1988

Properties of odour-binding glycoproteins from rat olfactory epithelium.

The specific membrane glycoproteins with high affinity for camphor and decanal were isolated from rat olfactory epithelium. Antibodies to these glycoproteins inhibited both the electroolfactogram and the binding of odorants. The enzyme immunoassay has shown these glycoproteins to be present in the olfactory epithelium of rat, mouse, guinea-pig and hamster but not in that of frog and carp. The molecular mass of the odour-binding glycoproteins from rat olfactory epithelium solubilized by Triton X-100 was approx. 140 kDa. They consisted of two subunits (88 and 55 kDa). The 88 kDa subunit was capable of binding odorants. The data obtained suggest that the glycoproteins isolated have some properties that make them plausible candidates for olfactory receptor molecules.

Aldehydes↗
PubMed1987

Time-dependent cGMP-activated conductance of detached patches of ROS plasma membrane.

cGMP markedly increases the cationic conductance of the 'inside-out' patches of rod outer segment plasma membrane when applied to the inner side. The cGMP-activated conductance of some patches was shown to be time-dependent. The data obtained suggest that the change of cGMP concentration in the near membrane layer underlies this phenomenon rather than the change in the channel's activity. The hydrolysis and, probably, the desorption of the nucleotide are responsible for this.

Animals↗
PubMed1986

Direct action of cGMP on the conductance of retinal rod plasma membrane.

In order to identify the intracellular transmitter in the phototransduction process in the retinal rod, the action of cGMP, 2',3'cGMP, cAMP, GMP and Ca2+ on the isolated inside-out patches of the plasma membrane of retinal rods of the frog (Rana temporaria) was studied. cGMP applied at the intracellular membrane surface markedly increased the conductance of patches. The action of cGMP took place in the absence of nucleoside triphosphates and, hence, was not mediated by protein phosphorylation. The dependence of cGMP-induced component of conductance on cGMP concentration was S-shaped, with half-saturation within 10-30 microM and a Hill coefficient of about 1.7-1.8. cAMP, 2',3'cGMP, GMP (1 mM) did not exhibit any action on the membrane. Ca2+ did not affect the patch conductance in the absence of cGMP. In the presence of cGMP, lowering Ca2+ concentration from 10(-3) to 10(-8) M decreased the cGMP-dependent component of conductance by 20-30%. The approximate value of the elementary event underlying the cGMP-induced conductance estimated from the magnitude of the variance of the cGMP-induced current is within 100-250 fS. We suppose that the cGMP-activated channels found by us provide the light-sensitive conductance of the rod plasma membrane in vivo and that cGMP is the intracellular transmitter acting in the phototransduction process.

Animals↗
PubMed1985

Molecular mechanisms of olfactory reception. VI. Kinetic characteristics of camphor interaction with binding sites of rat olfactory epithelium.

Camphor binding to a possible receptor of rat olfactory epithelium has been studied within the ligand concentration range 10(-11)-10(-6) M. At these concentrations camphor is bound by a set of receptors. They are distinguished by both the affinity to the ligand (K1 = 5 X 10(-10) M, K2 = 3.5 X 10(-8) M, K3 approximately equal to 10(-6) M) and their amount in the epithelium. The differences in the affinities are due to different values of the association rate constant of camphor (k1), which varies from 10(6) M-1 X s-1 for the receptors with high affinity up to 2 X 10(2) M-1 X s-1 for those with low affinity. These data are discussed in terms of equilibrium and kinetic models of the receptor-stimulus interaction.

Animals↗
PubMed1984

Single anion channels of frog rod plasma membrane.

Anion channels have been found in the plasma membrane of the outer and inner segment of the isolated retinal rod by means of the patch voltage-clamp technique. The permeability of the channels for different anions follows a sequence: Cl- greater than F- greater than NO3- greater than propionate; the channel conductance in the fully open state is 200 +/- 30 pS measured in 108 mM NaCl. The non-linear character of the current-voltage relationship at membrane potentials from -40 to -20 mV suggests that these anion channels may be involved in receptor potential generation through an electrogenic mechanism.

Animals↗
PubMed1984

Photoinduced isochromic rearrangement in rhodopsin.

Two tests have been used to detect and to study conformational rearrangements of cattle rhodopsin, occurring in the process of rhodopsin photolysis and resulting in no change in the visual pigment absorption spectrum. The first test concerns the ability of retinal to react with hydroxylamine. This ability occurs after photoisomerization of retinal with a time constant of 0.3 s at 20 degrees C reflecting this way a conformational transition demasking the retinal-opsin NC-bond. The other test takes advantage of the ability of rhodopsin to modulate the conductance of artificial lipid membranes. After a bleaching flash such a rhodopsin containing membrane shows a transient change in conductance. One of its characteristic time constants is that of NC-bond demasking. It shows that the "demasking" rearrangement is not an artefact due to presence of hydroxylamine and that it occurs in native rhodopsin. It has been shown that the "demasking" rearrangement is isochromic, not associated with known rhodopsin conformational transitions and, judging by its time characteristics, it may be of a functionally importance. The common scheme of rhodopsin photolysis has been modified to include a new conformational transition.

Animals↗
PubMed1983

Molecular mechanisms of odor sensing. VI. Some biochemical characteristics of a possible receptor for amino acids from the olfactory epithelium of the skate Dasyatis pastinaca and carp Cyprinus carpio.

The 25 000 x g pellet of skate and carp olfactory tissue was found to contain structures with high affinity for amino acids (Kd approximately 10(-10) M). Results from competition experiments suggest that a multiplicity of types of olfactory binding sites exists in the skate and carp. Some parameters of a possible receptor for amino acids were evaluated. The isoelectric point of these sites solubilized with Triton X-100 was 5.35 and the molecular weight was about 120 000-150 000.

Amino Acids↗