Physics of biological membranes. (1979)

Drawings by the cartoonist Jean Effel.

Scientists' notes on a slate.

Channels formed by proteins and some other substances, the so-called water pores, which ensure the permeability of biological membranes.

Institute of Biological Physics of the USSR Academy of Sciences.

Studies of various aspects of the mechanism and regulation of ion transport through cell membranes and organelles.

A layer-free lipid membrane is formed in the opening of the Teflon partition separating the water space.

An antibiotic from the polyene group is introduced.

Types of antibiotics in this group.

Chemical and geometric structure of these substances.

Model of the amphotericin B molecule .

The height of the molecule is equal to half the thickness of the membrane.

In an artificial membrane containing sterols, amphotericin B binds to this lipid.

Structures are created from such pairs, each of which has an antibiotic molecule and eight sterols.

These are the semipores of the future channel.

The layout of the membrane.

Cartoon explaining the formation of through pores permeable to anions.

As a result of experiments with amphotericin B, the operation of a single channel was recorded.

To test the dependence of the work of through pores on the structure of the antibiotic, a candidin molecule was taken, which differs from amphotericin B by only one group.

Cartoon explaining the method of measuring pores.

It has been found that in the presence of blocking ions, when the polarity of the voltage on the membrane changes, its conductivity first increases and then decreases.

A cartoon explaining this phenomenon, simultaneously with the demonstration of instrument readings.

Scientists have attempted to embed the channels of the excitable membrane of a living cell into the same lipid film.

Freshwater algae became the donor of native channels for the operation at the molecular level.

Studies have shown that there are two types of calcium and chlorine channels in its cell membrane.

Calcium is controlled by the voltage on the membrane.

When it is depolarized, they open.

Calcium ions enter the cell and open chlorine channels.

Chlorine ions rush out of the cell.

If we consider the moment of full opening of calcium channels, after opening they are inactivated.

The current subsides.

After the calcium channels, the chlorine ones are closed.

This is how the ion fluxes change over time when the potential is fixed on the membrane.

The process is visualized on the readings of the instruments.

If the membrane is depolarized by a short pulse, then the flows of these ions will cause the generation of a potential by action.

In the protoplasm of algae there are substances that, under certain conditions, are embedded in the membrane and form channels.

Algae under the microscope.

This circumstance was used in an experiment on the reconstruction of a natural channel in an artificial membrane.

The protoplasm of algae was divided into a number of fractions with different molecular weights.

The introduction of some of these fractions into a cell with an artificial membrane led to the formation of ion channels that spontaneously open and close.

The readings of the devices fixing this.

The channels are controlled by the voltage on the membrane.

Depending on the voltage, the ratio of the duration of its open and closed states and the value of the average current through the channel changes.

The nature of channel management is the same as in the cell membrane.

Thus, one of the proofs was obtained that the calcium channel of the algae cell was reconstructed in an artificial lipid film.

A cartoon explaining the real characteristics of the channels.

In this way, it was possible to reconstruct the channel of an electrically excitable cell membrane in an artificial membrane.

The dog runs around the field.

A hunting dog in a rack.

A scientist works in a laboratory.

In the foreground are flasks and other laboratory vessels and devices.

The Institute conducts intensive research on the work of the primary receptors of odorous substances and how odors are distinguished.

A scientist cuts out a small area from the olfactory lining of a frog.

With the help of enzymes, the prescription cell is separated.

A view of a cell under a microscope.

In Ringer's solution, it can live and function for a long time.

A cartoon explaining the process of determining the smell.

The experimenter draws a live prescription cell into the electrode.

The cell is included in the measuring system.

Camphor is served.

A cartoon explaining an experiment to determine the part of the lining in which there are receptors that bind molecules of this shape.

Laboratory equipment related to this experiment.

Test tubes.

The binding constant revealed as a result of the experiment.

Cartoon explaining the connection of receptors and membrane channels.

A stingray is floating in the sea.

In the olfactory lining of the stingray and carp, proteins similar to those from which the membrane receptors of the frog and rat are built are also found.

Carp swim in the aquarium.

These proteins have the ability to bind amino acids, which serve as an odorous stimulus for fish.

A cartoon explaining the process of removing odorous substances bound by receptors.

An experimenter among complex laboratory equipment.

A practical task is being solved - the construction of sensors that would react to small concentrations of odorous substances present in the medium.

Artificial lipid membranes that react to smell may allow us to move in this direction.

The human eye.

In the retina of the eye, one of the light-sensitive receptors is a wand.

A cartoon explaining the work of such a wand.

Experiment with a native channel.

A cartoon explaining a new theory of the transmission of light information.

Joint work of physiologists and biophysicists.

Using membranes and rhodopsin, the experimenters established the nature of the receptors' response to light.

Large, the faces of scientists working on solving complex problems.

Drawings by Jean Effel.