JPH046446A - Bioelement - Google Patents

Abstract

PURPOSE:To process information in the similar way to the visual sense of an organism by incorporating a pH indicator in liposome which is formed by using organism material or the material similar to the organism and converts incident light into pH change, and converting the change into the change in absorbance. CONSTITUTION:Artificial vesicles (liposome hereinafter) comprising organism material or the material similar to the organism wherein incident light can be converted into the pH change in the film are arranged on a substrate in two dimension. A pH indicator is contained in the liposome beforehand. The change in pH in the ribosome is converted into the absorbance of the contained pH indicator. When the absorbance is taken out as the information, it can be utilized in the information processing device, the input device or the output device of a bio-computer having the information processing pattern wherein the visual sense of an organism is simulated. Therefore, the effect of industrial utilization is high.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a biodevice that imitates the optical information processing function of living organisms.

(Prior Art) The information processing function of conventional computers is composed of silicon semiconductors, etc.
Neumann type computer (hereinafter referred to as a Neumann type computer) executes serial logical operations using the Neumann type computer. Although this method can perform quick logical operations, it has the drawback that it is essentially difficult to process a large number of information in parallel.

Such a photoresponsive element of a Neumann type computer uses, as an output medium, a current generated by converting incident photons as information from the outside into electrons.

On the other hand, the visual function of living organisms is expressed as described below. In the eye, which is an organ responsible for vision, cone-shaped cells 20 that detect color and rod-shaped cells 20 that detect brightness and darkness are arranged on the retina. FIG. 6 is a schematic explanatory diagram of such a rod-shaped body cell 20. In the figure, 11 is a disc membrane, 12 is a connecting cilia,
13 is mitochondria, 14 is Golgi apparatus, 15 is myoid, 16 is nucleus, 17 is external, 18 is segment, 19 is synaptic junction, and 20 is rod. When light enters the rods 20 arranged in the retina from the outside, rhodobusin, which is a light-responsive protein present in the disc membrane 11, undergoes a change, and the rhodopsin covalently bonded to this rhodopsin as a prosthetic group. )-retinal changes to trans-retinal, thereby releasing calcium ions contained within the disc membrane 11 into the cytoplasm.

Then, the increased calcium ions in the cytoplasm close the sodium channels in the cell membrane of each node 17 and cause hyperpolarization of the membrane potential of the cell membrane.

This becomes a signal to the synaptic junction 19, which reduces the release rate of inhibitory neurotransmitters and causes excitation of the postsynaptic neuron. These signals propagate one after another between neurons and are highly processed in the brain.

In this way, in vision, the field of potential changes in photoreceptor cells on the retina caused by light is processed by the brain and recognized as a pattern.

In recent years, many researchers have attempted to realize various functions that could not be satisfied by Neumann-type computers, based on the knowledge of biology and cerebral physiology, etc., as described in the following literature. It is expected that non-Neumann type computers, such as biocomputers, will be realized.

JP-A-63-111428 (Patent Application 6), -25694
0); Biochemical Experimental Methods, Vol. 17 “Structure and Function of Biomembrane Components”, p. 106; Walther, S., Richard, H.L.
and Roberto A, B.

“Bacteriorhodopsin and Th
e Purple Membrane of Halob
acteris BiochiIIIica and
Biophysica Acta
High Physical Power Acta), 505 (1979), 21
5-278 (Problem B to be Solved by the Invention) The photoresponsive element of the above-mentioned conventional phono-Neumann computer using semiconductors made of inorganic and organic materials converts incident photons as information from the outside into electrons. The output medium is the current generated by converting the information into the biocomputer, which has an information processing form that imitates the visual sense of a living body as described above, and is used as an information processing device, an input device, or an output device. The problem was that it had its own limits.

The present invention aims to solve this problem.

(Means for Solving the Problems) The present invention consists of a liposome that is formed using a biological material or a biosimilar material and converts incident light into a pH change.
This is characterized in that the change is converted into a change in absorbance of a po indicator.

(Function) In the present invention, artificial vesicles (hereinafter referred to as liposomes) made of a biological substance or a biosimilar substance that can convert the incident light into a pH change within the membrane are two-dimensionally arranged on a substrate,
A pH indicator is encapsulated in the liposome in advance, and the encapsulated pFl change in the liposome is converted into the absorbance of the indicator (pi), which is extracted as information, thereby enabling information processing similar to the visual sense of living things. become able to do it.

(Example) This invention will be explained below using specific examples.

11L ice 9'' Ll Halobacterlum halobium R,
M. was cultured at 39°C for 190 hours in a medium with the following composition.

Medium (per 10 liters) NaCl 12.5 kg MgSOa-7Hz0 200 g Trisodium citrate 30 g KCl
20 g peptone 10
0 g The obtained bacterial cells were suspended in 250 d of peptone-free culture solution, 5 μDNase was added, and 2 liters of 0.1 M
-Night dialysis with NaCIT. Tsuite, 40,000
g.

Centrifuge for 40 minutes, remove the resulting supernatant, suspend the reddish-purple precipitate in 300ml of 0.1M NaCl, homogenize with a Teflon homogenizer, and transfer to 40.000 g.
.

Centrifugation was performed for 40 minutes. This operation was repeated 2 to 3 times until the supernatant became colorless, and the precipitate obtained in the final operation was suspended in 6-10 water. Next, add 2-60% sucrose to the bottom of the tube for sucrose density gradient centrifugation, apply a 50-30% sucrose density gradient on top, and heat at 15°C.
Centrifuged at 100.000g for 17 hours. purpose p
urple me+5brane has a density of 1.18g/C
: It reached the position d and became balanced. Take out the purple band part, dilute it appropriately to lower the density, and then add 50,
The precipitate was collected by centrifugation at 000g for 30 minutes.

Purple membrane of proteoliposomes obtained as described above
ne(0,2μ-〇I Contains bacteriorhodopsin)
), the phospholipid azolectin in an amount 30 times that of bacteriorhodopsin, 1% by weight of the phospholipid antigen represented by the following formula (corresponding to the other binding factor in this example) relative to the phospholipid, 0.4 Xl (I ``wtχpi (indicator) Romthymol fill-0.3MKC/, and 0.4 s
MPyranine (8-hydroxy-1+
3+ 6+
Proteoliposomes were constructed by ultrasound at pH 7.3 (2mM-HEPES) in the presence of e). This was then dialyzed using the same solution that did not contain only the pH indicator as an external dialysis solution to remove the pH indicator remaining on the outside.

O=○ FIG. 1 is a schematic cross-sectional view of proteoliposome 39 obtained by the above-described operation. As can be understood from this figure, the photoresponsive protein bacteriorhodopsin 32 is inserted into the lipid bilayer 36 of the proteoliposome 39 containing the phospholipid antigen 33, penetrating the lipid bilayer 36. A pH indicator 34 is included inside the dialyzer 36 and isolated from the outside together with the above-mentioned external dialysis fluid.

Furthermore, as can be understood from the above formula, the phospholipid antigen 33 has an aromatic ring in its hydrophilic group, so the head polar group is bulky. Therefore, in the lipid bilayer 36,
There is a high probability that it exists in the outer layer with a large curvature.

Similarly, if the photoresponsive protein 32 in the proteoliposome 39 is reconstituted after a sufficient period of time as in the method described above, it is thought that it will be inserted in the same direction as in the living body. Further, the amount of the phospholipid antigen 33 added was approximately 1% by weight of the phospholipid 31, but this amount is such that the proteoliposomes 39 constituting the element are not attached to the substrate 4.
An antigen-antibody reaction occurs with the antibody 38 (corresponding to one binding factor in this example) attached to the substrate 42.
The amount may be 1% by weight or less than 1% by weight as long as it is a sufficient amount to be fixed.

As the pit indicator, in addition to the above-mentioned bromothymol blue, methyl red, 2,4-dinitrophenol, and the like are also used.

In order to confirm that the proteoliposome according to the present invention responds to light, the proteoliposome prepared by the above method was irradiated with visible light and the absorbance at a wavelength of 620 nm was measured.

The results are shown in the second session. ΔF during opening and opening is obtained by the following equation.

ΔF = (F, -F)/F, x 100 (Fo: Absorbance before visible light irradiation) Before and after visible light irradiation (in the figure, ON-...start of visible light irradiation, OFF→end of FF light irradiation) , a clearly significant internal solution pH change was observed. That is, it was confirmed that proton transport was carried out by the action of the photoresponsive protein 32 mentioned above. Furthermore, as can be seen from the figure, in the liposome prepared as described above, the pH changes due to incident light, and the pH change can change the absorbance of the indicator encapsulated in the liposome.

The above-mentioned embodiments are preferred examples to make this invention most easily understood, and it should be noted that various design changes can be made to these numerical conditions, materials used, etc. within the scope of the purpose of this invention. is clear.

- Next, a processing operation for forming an antibody as a monomolecular film on a substrate for constructing a biodevice of the present invention will be explained.

In this example, a case will be explained in which a glass substrate is used due to the flatness of the substrate surface and the ease of processing operations.
The substrate may be made of any other suitable material.

First, the substrate surface is hydrophobized by immersing it in octadecyltrichlorosilane in advance.

Antibody T-globulin obtained against phospholipid antigen 33 (particularly near the aromatic ring of older phospholipid antigens) was incubated with LangmuirBlodge
tt) Sub-phase of a water tank for film production Form a monomolecular film of the antibody on the aqueous solution by developing it on the water surface and compressing the ice surface. Due to the polar distribution of antibody molecules, this monolayer is formed in a certain direction, ie, with the antigen-binding region of the antibody facing down.

Next, the monomolecular film made of this antibody was transferred to the surface of a glass substrate with the surface treated to make it hydrophobic using a horizontal adhesion method.
LBBi 12 is formed on the substrate.

Figure 3 schematically shows such a board,
38 is an antibody, and 42 is a substrate.

Point 2: The substrate 42 on which the LBBi12 of the antibody as described above is deposited is immersed in a solution in which prepared liposomes are suspended, thereby causing an antigen-antibody reaction. The state of the two-dimensionally arranged liposomes is shown in FIG. 4. This figure schematically shows a state in which liposomes are immobilized on a substrate, and FIG. 5 schematically shows a part of a biodevice produced by the above-described method.

Such liposome arrays are produced by irradiating areas where antibodies are not needed from a substrate on which an LB film of antibodies is deposited with scanning ion beams such as gallium ions or electron beams, and denaturing them as shown in Figure 3 (a). By removing it, it is also possible to create a two-dimensional array pattern.

In order to confirm that the biodevice of the present invention obtained as described above responds to light, patterned light was irradiated onto the biodevice thus prepared, and a discolored region of the same pattern appeared on the surface of the device. Recognized as a yellow image.

(Effects of the Invention) As is clear from the above description, according to the biodevice of the present invention, the proteoliposomes are two-dimensionally arranged on the substrate and respond quickly to light as an external signal to adjust the pH of each. (lI! is changed, and these changes further increase the pH
The light emission wavelength of the indicator changes immediately, and by extracting this as information, it can be used in the information processing device, input device, or output device of a biocomputer, which has an information processing form that imitates the visual sense of living things. Therefore, the effect of industrial use is large.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of the proteoliposome of the present invention, Figure 2 is a characteristic diagram of the absorbance change, Figure 3 is W, ([3+
4 is a sectional view of the substrate of the present invention, FIG. 4 is a perspective view thereof, FIG. 5 is a sectional view of a part of a schematic element, and FIG. 6 is a schematic explanatory diagram of a general rod-shaped cell. 31... Phospholipid, 32... Photoresponsive protein, 3
4°...pH indicator, 39...proteoliposome,
42...Substrate.

Claims (2)

[Claims] (1) Consisting of a liposome formed using a biological material or a biosimilar substance that converts incident light into a pH change, a pH indicator is encapsulated within the liposome, and the pH change is converted into a change in absorbance of the pH indicator. A bio-element characterized by: (2) The biodevice according to claim 1, wherein the liposomes are two-dimensionally arranged on a substrate.