JP2006102896A - Molecular structure control method and molecular structure controlling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the steric structure and reactivity of a molecule by changing the conformation of the molecule not by a conventional chemical process but by varying the hydrogen bond or van der Waals' force as intramolecular or intermolecular weak force. <P>SOLUTION: The molecular structure control method is carried out by using the following molecular structure controlling apparatus to irradiate molecules with electromagnetic waves from an excitation electromagnetic wave source 9. The molecular structure controlling apparatus is equipped with: an electromagnetic wave source 1 for transmission spectra which emits electromagnetic waves having 0.1 to 15 THz frequencies and ≤0.01 J/cm<SP>2</SP>output power; an excitation electromagnetic wave source 9 which emits electromagnetic waves having 0.1 to 15 THz frequencies and 0.1 to 10<SP>6</SP>J/cm<SP>2</SP>output power; two condenser lenses 2, 10 which condense the electromagnetic waves from the electromagnetic wave sources onto molecules to irradiate the molecules; a sample substrate 3 to mount molecules; and observing means 7, 8 to observe electromagnetic waves transmitting the sample. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This invention irradiates a terahertz band electromagnetic wave to a conformation such as protein, DNA, antibody, etc., and breaks the hydrogen bond of this molecule or removes van der Waals force, The steric structure is controlled by changing the conformation.

  The three-dimensional structure of a molecule is determined by its conformation (conformation). This conformation is determined by hydrogen bonds and van der Waals forces, and plays an important role in biomolecules such as protein higher-order structure, DNA double helix, and antigen-antibody reaction.

On the other hand, it has recently been found that there is absorption peculiar to molecules in the frequency region of the terahertz band of 0.1 to 15 THz.
For example, “Chemical Physics Letters”, 320, 42-44, 2000, “Bulten Chemical Society Japan”, 75, 1083-1092, 2002 includes DNA, polypeptide, protein (albumin, The absorption spectrum of biomolecules such as collagen) is shown.

Further, in “Chemical Physics Letters”, Vol. 375, pages 337 to 343, 2003, an absorption spectrum of a peptide is shown. In “Chemical Physics Letters”, 332, 389-395, 2000, absorption spectra of cis- and trans-isomers of retinol were reported.
According to these reports, it has been experimentally clarified that differences in hydrogen bonding and van der Waals forces depending on the type and state of molecules appear as absorption in the terahertz frequency band.

However, these reports do not mention changing the conformation of this type of molecule by changing the hydrogen bond or van der Waals force.
“Chemical Physics Letters”, 320, 42-44, 2000 "Bulten Chemical Society Japan", 75, 1083-1092, 2002 “Chemical Physics Letters”, 375, 337-343, 2003 In “Chemical Physics Letters”, 332, 389-395, 2000

  The problem in the present invention is not the conventional chemical treatment, but changes the conformation by changing hydrogen bonds and van der Waals forces, which are weak forces acting within or between molecules, thereby changing the conformation of molecules. It is to be able to control the three-dimensional structure and reactivity.

To solve this problem,
The invention according to claim 1 irradiates an electromagnetic wave having a frequency of 0.1 to 15 THz and an output of 0.1 to 10 ⁶ J / cm ² dispersed and fixed for each molecule, It is a molecular structure control method characterized by changing the conformation.

The invention according to claim 2 irradiates a molecule in a state in which an electromagnetic wave having a frequency of 0.1 to 15 THz and an output of 0.01 J / cm ² or less is dispersed and fixed for each molecule to obtain an absorption spectrum of the molecule. The molecular structure control method characterized by irradiating the molecule with an electromagnetic wave having an absorption frequency output of 0.1 to 10 ⁶ J / cm ² appearing in the absorption spectrum to change the conformation of the molecule. is there.

  The invention according to claim 3 is characterized in that the method for observing the absorption spectrum of a molecule is any one of terahertz spectroscopy, Raman spectroscopy, infrared spectroscopy, fluorescence spectroscopy, and nuclear magnetic resonance spectroscopy. Item 3. The molecular structure control method according to Item 2.

The invention according to claim 4 is an electromagnetic wave source for excitation that emits an electromagnetic wave having an output of 0.1 to 10 ⁶ J / cm ² at a frequency of 0.1 to 15 THz, and the electromagnetic wave from the electromagnetic wave source for excitation is collected on a sample. A molecular structure control device comprising a condensing lens for irradiating with light and a sample stage on which the sample is placed.

The invention according to claim 5 is a transmission spectrum electromagnetic wave source that emits an electromagnetic wave having a frequency of 0.1 to 15 THz and an output of 0.01 J / cm ² or less, and a frequency of 0.1 to 15 THz and an output of 0.1 to 10 THz. An excitation electromagnetic wave source for emitting an electromagnetic wave of ⁶ J / cm ² , ^two condensing lenses for condensing and irradiating the electromagnetic wave from the electromagnetic wave source on the sample, a sample stage on which the sample is placed, and the above A molecular structure control apparatus comprising an observation means for observing an electromagnetic wave transmitted through a sample.

The invention according to claim 6 is the molecular structure control device according to claim 4 or 5, wherein the excitation electromagnetic wave source is of a variable frequency type.
The invention according to claim 7 is the molecular structure control device according to claim 4 or 5, further comprising sample control means for controlling the position of the sample.
The invention according to claim 8 is the molecular structure control apparatus according to claim 7, wherein the sample control means is optical tweezers.
The invention according to claim 9 is the molecular structure control device according to claim 4 or 5, characterized in that a temperature variable device for changing the temperature of the sample is provided.

The invention according to claim 10 is the molecular structure control device according to claim 9, wherein the temperature variable device changes the temperature according to the wavelength of the electromagnetic wave from the electromagnetic wave source.
The invention according to claim 11 is a molecule characterized in that the structure is controlled by the method according to any one of claims 1 to 3.

  In the present invention, “a molecule in a state of being dispersed and fixed for each molecule” is defined as a state in which one molecule or a molecule is several layers or less and the structural change of the molecule is not sterically hindered.

  According to the present invention, by irradiating terahertz band electromagnetic waves to molecules dispersed for each molecule, the hydrogen bonds and van der Waals forces of the molecules change, and the conformation thereof can be changed. Thereby, the three-dimensional structure and reactivity of the molecule can be controlled.

The present invention will be described in detail below.
FIG. 1 shows an example of the molecular structure control apparatus of the present invention.
In FIG. 1, reference numeral 1 indicates a transmission spectrum electromagnetic wave source, and 9 indicates an excitation electromagnetic wave source.

  As an electromagnetic wave source 1 for a transmission spectrum, for example, as shown in “Journal of Japanese Society of Radiological Technology”, Vol. 58, No. 4, pp. 441-447, a free electron laser, a P-type germanium laser, and a nonlinear optical effect are used. Terahertz parametric light source, two gallium arsenic photomixers for light mixing, terahertz band wave generator using femtosecond pulsed light, carbon dioxide laser excited molecular gas laser, backward wave tube (BWO: backward- a wave oscillator), an injection-type THz-wave parametric generator (is-TPG), or the like is used.

The transmission spectrum electromagnetic wave source 1 emits a continuous electromagnetic wave (continuous spectrum) in the entire wavelength range of a frequency of 0.1 to 15 THz or in a certain range. In other words, the electromagnetic wave having a frequency of 0.1 to 15 THz is a far infrared ray having a wavelength of 20 to 300 μm, and also has light properties such as straightness. The output of the electromagnetic wave from the transmission spectrum electromagnetic wave source 1 is set to 0.01 J / cm ² or less so that the conformation of the molecule irradiated with the electromagnetic wave does not change.

  The electromagnetic wave from the transmission spectrum electromagnetic wave source 1 is condensed by the condenser lens 2 to form a beam, which is irradiated to a local portion of the sample substrate 3. In the sample substrate 3, target molecules are dispersed and immobilized for each molecule. That is, the sample substrate 3 is obtained by applying a very dilute solution or dispersion of the target molecule on a transparent substrate such as silicon, quartz, synthetic resin, and drying, and the molecule is 1 It is in a state of a layer or less. If the molecules are not dispersed in each molecule, the structure change of the molecules is less likely to occur sterically when irradiated with electromagnetic waves.

The sample substrate 3 is placed on the temperature variable device 4 so that the temperature of the molecule can be controlled in the range of at least −269 ° C. to + 447 ° C.
This temperature variable device 4 receives the value of the wavelength of the electromagnetic wave emitted from the electromagnetic wave source 1 for transmission spectrum or the electromagnetic wave source 9 for excitation, and changes the temperature of the molecule based on this wavelength. For example, when the frequency of the electromagnetic wave is 0.1 THz, the temperature is controlled in synchronization with the frequency of the electromagnetic wave so that the temperature of the sample is −268.35 ° C. and + 446.7 ° C. at 15 THz.
Further, the temperature variable device 4 is placed on a movable stage 5 capable of three-dimensional fine movement so that the relative fine position of the beam of electromagnetic waves applied to the sample substrate 3 with respect to the sample substrate 3 can be controlled. It has become. The movable stage 5 here serves as a sample control means.

  The electromagnetic wave irradiated on the sample substrate 3 passes through the temperature variable device 4 and the movable stage 5 and enters the spectroscope 7 including a diffraction grating, an interferometer, a slit, a mirror, an optical filter, and the like through the condenser lens 6. Here, spectroscopy is performed and thermal type detection of thermocouples, pneumatic cells, pyroelectric detectors (TGS, DTGS, LATGS, etc.), bolometers (metal bolometers, thermistor bolometers, germanium bolometers, silicon bolometers, superconducting bolometers, etc.) Detector, photovoltaic detector (germanium detector, InSb detector, InAs detector, mercury cadmium tellurium detector, etc.), photoconductive detector (intrinsic semiconductor detector, Ge and Si impurity photoconductive detector, Ge And InP detector, InSb photodetector, etc.) Infrared image detector (PbS and PbSe array type detection) , InSb image detector, HgCdTe image detector, Schottky infrared CCD detector, etc.), photoconductive antenna, electro-optic crystal, InSb bolometer, etc. . Absorption spectrum in the 1-15 THz band is measured. The spectroscope 7 and the detector 8 here constitute sample observation means.

  The excitation electromagnetic wave source 9 emits an electromagnetic wave having a specific frequency (so-called monochromatic light) within a frequency range of 0.1 to 15 THz, and is a free electron laser similar to the previous transmission spectrum electromagnetic wave source 1, P-type germanium laser, terahertz parametric light source using nonlinear optical effect, device for optical mixing with two gallium arsenide photomixers, terahertz band wave generator using femtosecond pulsed light, carbon dioxide laser excited molecular gas Lasers, backward wave tubes, light injection type terahertz wave parametric generators, etc. are used.

Further, since the excitation electromagnetic wave source 9 changes molecular hydrogen bonds and van der Waals forces, its output is higher than that of the transmission spectrum electromagnetic wave source 1 and is 0.1 to 10 ⁶ J / cm ^2. is a range, it is less than 0.1 J / cm ² can not give a change in conformation of the ^molecule, it exceeds 10 6 J / cm ^2, molecule itself may be damaged.
The terahertz band electromagnetic wave from the excitation electromagnetic wave source 9 is condensed by the condenser lens 10 and irradiated onto the molecules on the sample substrate 3.

An example of a molecular structure control method using such a molecular structure control apparatus will be described.
First, a sample substrate 3 is prepared by fixing molecules of interest on a substrate in a state where each molecule is dispersed, and this is placed on a temperature variable device 4.
Next, the transmission spectrum electromagnetic wave source 1 is operated, and an electromagnetic wave having an output of 0.01 J / cm ² or less to a molecule on the sample substrate 3 through a condenser lens 2 in a continuous spectrum in a frequency range of 0.1 to 15 THz. Irradiate. At this time, the temperature variable device 5 is operated to cool the temperature of the molecules on the sample substrate 3 to −268.35 to + 446.7 ° C. This temperature is changed in accordance with the change in the frequency of the electromagnetic wave, and is set to −268.35 ° C. when the frequency is 0.1 THz, and is synchronized with the frequency so as to be + 446.7 ° C. when the frequency is 15 THz. Further, the movable stage 5 is operated so that the target molecule is irradiated with electromagnetic waves.

The electromagnetic wave transmitted through the sample substrate 3, the temperature variable device 4, and the movable stage 5 enters the spectroscope 7, and is further guided to the detector 8, where the absorption spectrum of the molecule in the 0.1 to 15 THz band is measured. .
Next, an electromagnetic wave having an output of an absorption peak frequency of 0.1 to 10 ⁶ J / cm ² appearing in this absorption spectrum is emitted from the excitation electromagnetic wave source 9, and passes through the condenser lens 10 to molecules on the sample substrate 3. Irradiate. At this time, the temperature variable device 5 is operated to set the temperature of the molecules on the sample substrate 3 to a temperature corresponding to the frequency of the absorption peak.

As a result, the hydrogen bond of the molecule is broken or the van der Waals force is removed, and the conformation of the molecule changes accordingly, and the three-dimensional structure of the molecule changes.
The change in the three-dimensional structure of the molecule can be confirmed by irradiating the terahertz band electromagnetic wave from the transmission spectrum electromagnetic wave source 1 again and taking the absorption spectrum of the molecule.
Further, if the absorption peak of the molecule is known in advance, the step of measuring the absorption spectrum can be omitted, and the transmission spectrum electromagnetic wave source 1 can be omitted.

In such a molecular structure control method, the target molecule is irradiated with an electromagnetic wave having an output of 0.1 to 10 ⁶ J / cm ² at a specific frequency in the range of 0.1 to 15 THz, thereby hydrogen bonding of the molecule. Is cut or van der Waals forces are reduced and eliminated. As a result, the conformation of the molecule is changed, and the three-dimensional structure can be changed.

  The molecule of the present invention is a molecule whose molecular structure has been changed by the molecular structure control method described above.

In the embodiment shown in FIG. 1, the sample observation means comprising the spectroscope 7 and the detector 8 is based on infrared spectroscopy, but besides this, terahertz spectroscopy, Raman spectroscopy, fluorescence spectroscopy, nuclear magnetics Any of resonance spectroscopy may be used.
Moreover, you may use an optical tweezers as a sample control means. The optical tweezers capture fine particles such as molecules in a non-contact and non-destructive manner by the optical pressure of the laser light, and the molecules can be fixed at a desired position by finely moving the laser light.

Hereinafter, although a specific example is shown, this invention is not limited by this specific example.
(Example 1)
Experiments were performed using the molecular structure control apparatus shown in FIG.
As a transmission spectrum electromagnetic wave source 1, a pulse laser (Spectra Physics, wavelength 800 nm, pulse width 70 fs, power 1 W) is irradiated onto a photoconductive antenna composed of a low-temperature grown gallium arsenide substrate bonded to a Si hemispherical lens, A terahertz wave of 0.2 to 2.5 THz and 1 μW was obtained.

  As the detector 8, a photoconductive antenna composed of a low-temperature grown gallium arsenide substrate bonded to a Si hemispherical lens was used. When the terahertz absorption spectrum was measured for the molecule of all-trans-retinal (manufactured by Sigma Aldrich) that was sufficiently dispersed and immobilized in a polyethylene film at a temperature of 10K, as shown by curve (a) in FIG. There were absorption peaks near 4 THz, 1.6 THz, and 1.9 THz.

A carbon dioxide laser excited molecular gas laser (Coherent, SIFIR-50) is adjusted as an excitation electromagnetic wave source 9 to a frequency of 1.89 THz and an output of 50 mW, and is converged to a diameter of about 1 mm by a polyethylene lens to be an all-trans-retinal. Irradiated for 1 minute. When the absorption spectrum was measured after the irradiation, a phenomenon of peak intensity of the irradiated frequency was observed as shown by the curve (b) in FIG.
With reference to “Chemical Physics Letters, Vol.332, 389-395, 2000”, it was found that this was a molecular structure changed to 13-cis-retinal.

  Furthermore, when this 13-cis-retinal was irradiated in the same manner with a frequency of 1.4 THz and an output of 50 mW, it changed as shown in the curve (c) of FIG. 2, and the molecular structure changed to 11-c cis-retinal. I was able to confirm.

(Example 2)
The same equipment as in Example 1 was used. Streptavidin as a sample was sufficiently dispersed and applied to a highly transparent silicon substrate with high transparency in the terahertz region and immobilized.
Laser light adjusted to a frequency of 1.6 THz and an output of 40 mW at a temperature of 120 K was focused to a diameter of about 1 mm by a polyethylene lens, and the laser was scanned linearly with a width of 1 mm.

Thereafter, the sample was immersed in a biotin solution and further incubated with a streptavidin solution modified with CdSe quantum dots. Then, the image of the boundary area | region of the irradiation site | part of a terahertz laser beam and a non-irradiation site | part was measured using the fluorescence microscope of wavelength 488nm excitation.
As a result, as shown in FIG. 3, it was confirmed that the antigen-antibody reaction of streptavidin-biotin was efficiently promoted at the irradiation site A of the terahertz laser beam.

It is a schematic block diagram which shows an example of the molecular structure control apparatus of this invention. 6 is a graph showing an absorption spectrum in specific example 1. It is a photograph which shows the image which shows the result in the specific example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electromagnetic wave source for transmission spectra, 2 ... Condensing lens, 3 ... Sample substrate, 4 ... Temperature variable device, 5 ... Movable table, 6 ... Condensing lens, 7 ..Spectroscope, 8... Detector, 9... Excitation electromagnetic wave source, 10.

Claims (11)

Irradiating an electromagnetic wave having a frequency of 0.1 to 15 THz and an output of 0.1 to 10 ⁶ J / cm ² to each molecule in a dispersed and fixed state to change the conformation of the molecule. A molecular structure control method. An electromagnetic wave having a frequency of 0.1 to 15 THz and an output of 0.01 J / cm ² or less is irradiated to each molecule in a dispersed and fixed state to obtain an absorption spectrum of the molecule, and appears in the absorption spectrum. A molecular structure control method, wherein the molecule is irradiated with an electromagnetic wave having an absorption frequency output of 0.1 to 10 ⁶ J / cm ² to change the conformation of the molecule.   3. The molecular structure control method according to claim 2, wherein the method for observing the absorption spectrum of the molecule is one of terahertz spectroscopy, Raman spectroscopy, infrared spectroscopy, fluorescence spectroscopy, and nuclear magnetic resonance spectroscopy. . In frequency 0.1～15THz, the excitation electromagnetic source for emitting an electromagnetic wave output 0.1~106 ^J / cm ^2, a condenser lens for irradiating condenses the electromagnetic waves from the excitation electromagnetic wave source in the sample A molecular structure control apparatus comprising a sample stage on which the sample is placed. In frequency 0.1～15THz, the transmission spectrum for electromagnetic radiation source for emitting an output 0.01 J / cm ² or less in an electromagnetic wave at a frequency 0.1～15THz, the electromagnetic wave output 0.1~10 ⁶ J / cm ² An excitation electromagnetic wave source to be emitted, two condensing lenses for condensing and irradiating electromagnetic waves from these electromagnetic wave sources to the sample, a sample stage on which the sample is placed, and an electromagnetic wave transmitted through the sample are observed A molecular structure control device comprising an observation means.   6. The molecular structure control apparatus according to claim 4, wherein the excitation electromagnetic wave source is a frequency variable type.   6. The molecular structure control apparatus according to claim 4, further comprising sample control means for controlling the position of the sample.   8. The molecular structure control apparatus according to claim 7, wherein the sample control means is optical tweezers.   6. The molecular structure control apparatus according to claim 4, further comprising a temperature variable device that makes the temperature of the sample variable.   10. The molecular structure control device according to claim 9, wherein the temperature variable device changes the temperature according to the wavelength of the electromagnetic wave from the electromagnetic wave source. A molecule whose structure is controlled by the method according to any one of claims 1 to 3.

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