JPH10197529A - Antigen deciding group anticipating method and system for protein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To anticipate a peptide becoming a specific antigen deciding group by finding a peptide having a high aptitude evaluating value from primary alignment information on an amino acid of protein, and also finding a peptide having higher specificity in a constant protein group. SOLUTION: An evaluating value to show an aptitude as an antigen deciding group is found to respective peptides of the first prescribed number obtained from primary alignment information on an amino acid residue to show protein being an analytical object. Data corresponding to a frequency in which the second prescribed number of amino acid residues in its peptides appear in a prescribed protein group, is found as specific data with every peptide higher in its evaluating value. In this case, the second prescribed number is set not more than the first prescribed number, and may be set equal to each other. When a frequency obtained to the second prescribed number of amino acid residues in the peptides is small, the specific data shows a high specificity condition. A peptide capable of becoming an antigen deciding group higher in specificity can be estimated on the basis of this specific data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and system for predicting an antigenic determinant of a protein, and more particularly to a peptide which can be a specific antigenic determinant characterizing a protein from primary sequence information of amino acid residues representing the protein. The present invention relates to a method and a system for predicting and displaying. The method and system can be used in all fields of identifying biological functions of biochemistry (genes, proteins).

[0002]

2. Description of the Related Art Heretofore, the present applicant has proposed a system for predicting an antigenic determinant from primary sequence information of amino acid residues representing a protein (Japanese Patent Application No. 7-330873).
In this conventional system, a primary value of an amino acid residue representing a protein is calculated for each peptide having a predetermined number of residues, and an evaluation value indicating a height that can serve as an antigenic determinant is calculated according to a predetermined algorithm. Then, the evaluation value is displayed in a graph in association with the primary sequence of the amino acid residue, and the peptides are displayed in descending order of the evaluation value.

[0003] The above evaluation values are obtained by numerically expressing evaluations such as flexibility evaluation, hydrophilicity / hydrophobicity evaluation, antigenic determinant analysis evaluation, secondary structure prediction evaluation and the like, and expressing the numerical values alone or in combination. is there. Each evaluation method (algorithm)
Has been published in various papers and is known.

[0004] Researchers have determined that a peptide having a high evaluation value displayed as described above is likely to be an antigenic determinant, and biochemically synthesize such a peptide, and then synthesize the synthesized peptide. It is used for various experiments to identify the properties of the protein.

[0005]

By the way, in order to specify a function specific to a protein to be analyzed, an antigenic determinant specific to the protein, that is, a specific antigenic determinant must be found. However, the conventional antigenic determinant prediction system does not provide any information as to whether or not the antigenic determinant is specific to the protein to be analyzed.

Accordingly, an object of the present invention is to provide a method and system for predicting an antigenic determinant of a protein, which can predict a peptide which can be a specific antigenic determinant characterizing the protein.

[0007]

Means for Solving the Problems To solve the above problems, a method for predicting an antigenic determinant of a protein according to the present invention comprises:
As described in claim 1, an antigenic determinant according to a predetermined algorithm for each peptide composed of a first predetermined number of amino acid residues obtained from primary sequence information of amino acid residues representing a protein to be analyzed. The evaluation value representing the degree of suitability is determined, a predetermined number of peptides having a high evaluation value are selected, and for each of the selected peptides, the second predetermined number of amino acid residues contained in the peptide is a predetermined protein group In the data corresponding to the frequency that appears in the as specificity data representing the specificity of the peptide,
Based on the specificity data, a peptide which can be an antigenic determinant with higher specificity in the protein to be analyzed is estimated.

In the method for predicting the antigenic determinant of a protein as described above, an evaluation value indicating the suitability as an antigenic determinant is given to each peptide obtained from the primary sequence information of amino acid residues representing the protein to be analyzed. Can be Then, for each peptide having a higher evaluation value, data corresponding to the frequency at which the second predetermined number of amino acid residues contained in the peptide appear in the predetermined protein group is specificity data representing the specificity of the peptide. Asking. The specificity data indicates a high specificity state when the frequency obtained for the second predetermined number of each amino acid residue contained in the peptide is generally low.

[0009] Based on the specificity data thus obtained, a peptide which can be an antigenic determinant having higher specificity in the protein to be analyzed is estimated.
The number of amino acid residues (first predetermined number) constituting each peptide obtained from the amino acid primary sequence of the protein to be analyzed, and the number of amino acid residues (first number) contained in each peptide whose frequency is to be obtained The second predetermined number is equal to or less than the first predetermined number. Therefore, the first predetermined number and the second predetermined number may be equal. In this case, the specificity data corresponds to the frequency of appearance of the peptide itself obtained from the primary amino acid sequence of the protein to be analyzed in the protein group.

[0010] The predetermined protein group is, for example, a database of known proteins (for example, SW).
ISS-PROT) can be used. Further, in order to solve the above-mentioned problem, the protein antigenic determinant prediction system according to the present invention provides a protein antigenic determinant prediction system, as described in claim 2, which is obtained from primary sequence information of amino acid residues representing a protein to be analyzed. Evaluation value calculating means for evaluating suitability as an antigenic determinant for each peptide composed of one predetermined number of amino acid residues according to a predetermined algorithm, quantifying the evaluation result and outputting it as an evaluation value, A primary prediction means for selecting a predetermined number of peptides having a high evaluation value obtained by the arithmetic means, and for each peptide selected by the primary prediction means, a second predetermined number of amino acid residues contained in the peptide are determined. A specificity data calculating means for quantifying data corresponding to the frequency of occurrence in the protein group as specificity data representing the specificity of the peptide; Prediction means for estimating a peptide that can be a more specific antigenic determinant in the protein to be analyzed based on the specificity data obtained by the data calculation means, and a peptide predicted by the secondary prediction means And output means for outputting together with the specificity data.

In such a system for predicting an antigenic determinant of a protein, specificity data is given to a peptide having high eligibility (high evaluation value) as an antigenic determinant, as in the above-described prediction method. This specificity data is data corresponding to the frequency at which a second predetermined number of amino acid residues contained in each peptide appear in a predetermined protein group. Then, a peptide that can be a specific antigenic determinant in the protein to be analyzed is estimated based on the specificity data, and the estimated peptide is output from the output unit together with the specificity data.

The user of this antigenic determinant prediction system is
By looking at the output result, a peptide that can be a specific antigenic determinant in the protein to be analyzed can be identified. The output unit may be a display unit that displays the estimated peptides together with the specificity data, a printer that prints them out, or a transmission unit that transmits them to another system.

[0013] Further, from the viewpoint of easily obtaining data corresponding to the frequency, the present invention provides, as described in claim 3, the above-mentioned specificity data calculating means, wherein the primary amino acid sequence of a protein to be analyzed is used. For each second predetermined number of amino acid residues obtained from, a frequency data receiving means for receiving the frequency of occurrence of the amino acid residue in a predetermined protein group from an external unit, and the second data included in each of the peptides Frequency addition means for extracting and adding the frequency of each of the predetermined number of amino acid residues from the frequency group received by the frequency data reception means, and adding the frequency addition value obtained by the frequency addition means to the specificity of each peptide. And sex data.

The frequency of occurrence of the second predetermined number of the amino acid residues in the predetermined protein group is determined by CD-RO
M, a recording medium, a host system connected to the system via a local network such as an intranet,
It can be supplied from another system or the like via a public network such as the Internet.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The system according to the present invention is constructed, for example, in each terminal computer system connected to a host system by an intranet as shown in FIG. In FIG. 1, a host system (database server) 100 and terminal computer systems 200 (1) to 200 (10) are mutually connected by an intranet N, and information communication can be performed between these systems. A disk unit 120 is connected to the host system 100. The disk unit 120 stores a database (for example, SWISS-PROT) relating to published proteins. The database relating to the protein is supplied to the host system 100 via a recording medium such as a CD-ROM or a public network.

Each terminal computer system 200 (1)
The hardware configuration of the devices 200 to (10) is, for example, as shown in FIG. 2, the system includes a control unit 10 (CPU), a display unit 2
0, I / O interface 30, memory unit 40,
Input unit 50, CD-ROM drive unit 60
And a communication unit 80. These units and the I / O interface are interconnected by a bus. Further, a disk unit 70 is connected to the bus via the I / O interface 30.

The control unit 10 controls the entire system and executes a process related to predicting the antigenic determinant of a protein, as described later. The display unit 20 is C
Various data (evaluation value, frequency distribution, etc.) obtained by the processing of the prediction of the primary amino acid sequence of the protein and the antigenic determinant based on the processing in the control unit 10 ), Various windows relating to prediction results and the like are displayed on the screen. Memory unit 40
Includes a RAM and a ROM, and stores a program to be executed by the control unit 10, necessary data obtained in the course of processing according to the program, data to be displayed on the screen of the display unit 20, and the like. .

The input unit 50 includes a keyboard, a mouse, and the like, and is used by a user (researcher) to input information to the system. The communication unit 80 performs information communication with the host system 100 via the intranet N. The CD-ROM 100 stores a program describing a process related to predicting an antigenic determinant of a protein. CD-ROM drive unit 60
The program is installed in the disk unit 70 from the CD-ROM 100 set in the. Then, when executing a process relating to prediction of the antigenic determinant of a protein, the program read from the disk unit 70 and that controlled by the control unit 10 are stored in the memory unit 40 (RAM). In this state, the control unit 10 (CPU) performs processing relating to prediction of the antigenic determinant of the protein according to the program stored in the memory unit 40.

Each terminal computer system 200 (1)
3 to 200 (10), the researcher
The process proceeds according to the procedure shown in. In FIG. 3, first, when primary sequence information of a protein to be analyzed is input to the system, a search process P1 for an antigenic determinant in the protein is executed. For this antigenic determinant search process P1, for example, a conventional method disclosed in Japanese Patent Application No. 7-330873 is applied.

That is, a peptide composed of seven amino acid residues is selected from the input amino acid primary sequence information, and the selected peptide is subjected to an evaluation process according to a predetermined algorithm. To give an assessment of the suitability of the antigenic determinant. The peptide composed of seven residues to be evaluated is updated, for example, as shown in FIG. 4 by shifting one residue from the first residue of the primary sequence (...).

The evaluation values given to the peptides sequentially updated as described above are associated with the central residue (representative residue) of the amino acid residue sequence constituting each peptide (see FIG. 4). As shown by the arrow, it is associated with the fourth residue from the beginning). That is, the evaluation value given to each peptide is stored in the memory unit 40, and as shown in FIG. 6, the evaluation value is stored in each storage area of the antigenic determinant prediction buffer having a storage area corresponding to each residue. A pointer value indicating the storage position of the evaluation value of the peptide whose corresponding residue is the representative residue is stored.

As described above, evaluation values for each peptide are quantified in the same manner as described above, such as flexibility evaluation, hydrophilicity / hydrophobicity evaluation, antigenic determinant analysis evaluation, secondary structure prediction evaluation, and the like. This is a single or multiple integrated representation. Flexibility assessment is described, for example, in "PAKarplus and GE Sc
hulz, Prediction of Chain Flexibility, Naturwissen
chaften 72, 212-213 (1985) ". The hydrophilicity / hydrophobicity evaluation is performed by, for example," J. Kyte and RFDoolittle, A simple Methodfor
Displaying the Hydropathic Character of a Protein,
J. Mol. Biol 157, 105-132 (1982) ". An antigenic determinant analysis evaluation is performed by, for example," EAEmini, Induction of Hepatitis A Virus-N
eutralingAntibody by a Virus-Specific Synthetic Pe
ptide, J. Virol. 55, 836-839 (1985) ". The secondary structure prediction evaluation
For example, "J. Garnier, Analysis of Accuracy and Impli
cations of Simple Methods for Predicting the second
ary structure of Blobular Proteins, J. Mol. Biol. 12
0,97-120 (1978) ".

When an evaluation value is given to each peptide obtained from the primary sequence of the protein as described above,
The rank is set in the descending order of the evaluation value (in the order of higher eligibility as the antigenic determinant), and the pointer value to the rank corresponds to the representative residue of the peptide in the antigenic determinant prediction buffer (see FIG. 6). Is set in the specified storage area.

As described above, the antigen determinant search process P
When 1 is completed, the evaluation value for the residue number representing the representative residue is graphically displayed on the screen of the display unit 20, for example, as shown in FIG. Further, when the user (researcher) specifies the number n (for example, n = 3) of the antigenic determinants to be selected by using the input unit 50, the control unit 10
Scans the antigenic determinant buffer (see FIG. 6)
The peptides with the highest n (n = 3) ranks are selected (P2 in FIG. 3). Then, the rank of the selected peptide (Ra
nk of Epitope), the amino acid residue sequence representing the peptide (Re
sidue Name) and the residue number (Re
Sidue No.) is further displayed on the screen of the display unit 20 (see FIG. 5).

By looking at the above graphical representation, the researcher can know the approximate position on the primary sequence of the peptide which is expected to have a high suitability of the antigenic determinant, and can further display the rank and the residue sequence. The specific peptide predicted to have high suitability for the antigenic determinant can be known by looking at the above.

Here, the user further operates the input unit 50.
When the start command of the frequency distribution creation processing (P3 in FIG. 3) is input to the system by using, the control unit 10 starts the frequency distribution creation processing P3. This frequency distribution creation processing P
In 3, first, an input window as shown in FIG. 8 is displayed on the screen of the display unit 20. Using the input unit 50 (mouse, keyboard), the user uses the input window to determine the size of the oligopeptide whose frequency is to be determined (four-residue oligopeptide: Tetrapeptides, five-residue oligopeptide: Pentapeptides, 6-residue oligopeptide: Hexapeptides) and the primary sequence information of the protein to be analyzed (AAAYXLVVVG ASG
V ...). For example, in the case of this example, oligopeptides (Pentapeptides) of a 5-residue string are specified. Then, the user uses the input unit 50 to specify the range of the protein for which the frequency is to be calculated (All species, Human species: Human, Mouse species: Mouse, etc.).

Since the primary sequence information of the protein to be analyzed to be input into the input window is the same as the information targeted in the above-described antigenic determinant search processing P1, the primary sequence information is not displayed when the input window is opened. Can be automatically set to.

After the various information settings are completed as described above, when the control button "OK" is selected (mouse click operation) on the input window, the control unit 10 starts the input amino acid primary operation. From the sequence information, the specified oligopeptide (five residue sequence) is selected as the target for which the frequency is to be determined. The oligopeptide composed of the target five residues is updated, for example, as shown in FIG. 9 by shifting one residue from the first residue of the primary sequence (
. . . ).

The oligopeptides sequentially selected in this manner are transmitted to the host system 100 via the communication unit 80 together with information on the range of the protein whose frequency is to be obtained, which is input to the input window. Host system 100
Then, the database stored in the disk unit 120 is scanned to determine the frequency of occurrence of the specified oligopeptide within the specified range of proteins (protein group). As a method for obtaining the frequency, a known method is used (for example, Japanese Patent Application No. 8-203575).

The host system 100 returns the obtained frequency data to the terminal computer system 200. In the terminal computer system 200 that has received the frequency data corresponding to each oligopeptide via the communication unit 80, the frequency data received by the control unit 10 is stored in the memory unit 40. And, furthermore, the control unit 1
0 indicates that the corresponding residue is a representative residue (residue located at the center of the peptide (arrow in FIG. 7) in each storage region of the frequency buffer having a storage region corresponding to each residue as shown in FIG. Set the pointer value indicating the storage position of the frequency data for the oligopeptide to be referred to))).

When the frequency data for all oligopeptides (five residue strings) is received and pointer values are set in storage areas corresponding to all the residues in the frequency buffer, the control unit 10 , The frequency of each oligopeptide is graphically displayed on the screen of the display unit 20, for example, as shown in FIG. As shown in FIG. 11, details of this graph display are as follows: the ordinate represents the residue number of the amino acid residue in the primary sequence of the protein to be analyzed, and the abscissa represents the residue identified by the residue number. Is represented by a bar graph.

After displaying the frequency of each oligopeptide on the display unit 20 as described above, the control unit 10 ranks the peptides in descending order of specificity based on the frequency (P4 in FIG. 3). ) And a process of displaying the ranked peptides (P5 in FIG. 3). The process P4 for ranking the peptides is as follows:
For example, it is performed according to the procedure shown in FIG.

In FIG. 12, the control unit 10 sets the evaluation rank Ro in a predetermined register (S1).
The evaluation rank Ro corresponds to the number of peptides to be extracted as an antigenic determinant specific to the protein, and the top Ro (e.g., three) of the above-described evaluation values is a peptide whose specificity is to be determined. Becomes And the control unit 1
0 sets the counter value i to “1” (i = 1) (S2), and then refers to the antigenic determinant prediction buffer (see FIG. 6) to determine the i-th (first) i-th peptide. The evaluation rank R (residue data) of (seven residue strings) is acquired (S
3). Then, the control unit 10 determines that the obtained evaluation rank R is equal to or less than the evaluation rank Ro set above (R ≦ R
o) is determined (S4).

If the obtained evaluation rank R is equal to or less than the set evaluation rank Ro (within the upper Ro rank), the control unit 10 refers to the frequency buffer (see FIG. 7) and , I-th, and (i + 1) -th consecutive oligopeptides (five residue strings) are read out from the memory unit 40 and added (S5).

The addition of the frequencies of three consecutive oligopeptides means the following. As shown in FIG. 13, the peptide to be evaluated now has a 7 residue sequence (i-
3, i-2, i-1, i, i + 1, i + 2, i + 3), and the oligopeptide whose frequency is determined is composed of 5 residues. Therefore, among the peptides to be evaluated (seven residue sequences), there are three oligopeptides whose frequencies have been determined. That is, the representative residues of the oligopeptide for which the frequency is obtained coincide with the (i-1) -th, i-th, and (i + 1) -th residues of the peptide to be evaluated.

Therefore, the (i-1) th,
The addition value obtained by adding the frequencies of the i-th and (i + 1) -th consecutive three oligopeptides is the frequency of all the oligopeptides contained in the peptide to be evaluated (seven residue sequence). . The added value of the frequency serves as a scale indicating the specificity (the degree of occurrence in the protein group) of the peptide to be evaluated (seven residue sequence). That is, the smaller this frequency addition value is (the more rare it is within a protein), the higher its specificity is.

As described above, the obtained frequency addition value is stored in the memory unit 40, and the pointer to the frequency addition value is stored in the i-th storage area of the antigenic determinant prediction buffer (see FIG. 6). The value is stored (S6). Then, the control unit 10 determines whether or not the counter value i is the final value corresponding to the last residue number of the amino acid primary sequence (S7), and increases the counter value i by +1 until the final value is reached.
While incrementing each time (S8), the same frequency addition processing as described above is performed on the peptides up to the evaluation rank higher Ro (S3 to S6). When the evaluation rank R of the i-th peptide is larger than the set evaluation rank Ro (rank lower than the evaluation rank Ro), the above-described addition processing of the frequency is not performed (S4 → S7).

When the processing for all the peptides has been completed (i = END), the control unit 10 scans the antigenic determinant prediction buffer (see FIG. 6), reads out the frequency addition values, and reads the values in ascending order. A rank (frequency rank) is given (S9). Further, the control unit 10 sets a pointer value indicating the frequency rank for each peptide in the corresponding storage area of the antigenic determinant prediction buffer (S1).
0).

After the frequency rank pointer value is set in the antigenic determinant prediction buffer as described above, the control unit 10 performs a display process of the ranked peptide (P5 in FIG. 3). Display processing P5 of this peptide
Is performed, for example, according to the procedure shown in FIG.

In FIG. 14, the control unit 10 first waits for an operation input of a predetermined control button (mouse click operation) (S11). In this state, when the user performs an operation of selecting a predetermined control button (Specific Epitope Find), the control unit 10 detects the operation and initializes the counter value i (i = 1) (S1).
2) With reference to the antigenic determinant prediction buffer (see FIG. 6), the frequency rank R of the i-th peptide is obtained (S1).
3). Then, the control unit 10 determines whether or not the acquired frequency rank R is equal to or less than the predetermined frequency rank Rs (R
≤ Rs) (S14). In addition, this rank Rs
Is set to a predetermined value equal to or lower than the evaluation rank Ro used in the processing shown in FIG.

When the acquired frequency rank R is equal to or smaller than the predetermined rank Rs (within the upper Rs), the control unit 10 refers to the antigenic determinant prediction buffer (see FIG. 6) and evaluates the i-th peptide evaluation value (antigen determination). Group accuracy), frequency addition value (specificity) and (i-3) th to (i)
+3) The data to be displayed such as the amino acid residue (i-th peptide name) is displayed in a display buffer (memory unit 4).
0) (S15). And the control unit 1
0 determines whether or not the counter value i is the final value corresponding to the last residue number of the amino acid primary sequence (S16), and increments the counter value i by +1 until the final value is reached (S17). For the peptides up to the frequency rank higher Rs, the same data set processing is performed on the display buffer as described above (S13 to S15).

If the frequency rank R of the i-th peptide is larger than the predetermined rank Rs, the above-described data set processing for the display buffer is not performed (S14 → S1).
6). When the processing for all the peptides is completed (i = END), the control unit 10 sorts the data in the display buffer according to the frequency rank (S1).
8). When the data sorting is completed, the control unit 10
Performs display processing P10 of data (evaluation value, peptide name, peptide residue number, frequency addition value) in the display buffer. In the display processing P10, the data in the buffer is provided to the display unit 20, and for example, as shown in FIG. 10, the data is displayed below the frequency display window on the screen of the display unit 10.

That is, Rs (for example, R
s = 3), its frequency rank (Rank of Function)
al Site), a peptide name (Residue Name), a residue number (Residue No.), an evaluation value (Score), and a frequency addition value (Number) are displayed. By viewing this display, the user (researcher) can know the peptide predicted as a specific (highly specific) antigenic determinant contained in the protein to be analyzed.

In the example described above, the antigen determinant search processing P1 shown in FIG. 3 corresponds to the evaluation value calculation means, the processing P2 shown in FIG. 3 corresponds to the primary prediction means, and the frequency distribution shown in FIG. Creation process P3 corresponds to specificity data calculation means.
Further, a process of ranking peptides in descending order of specificity based on frequency (P4 in FIG. 3), specifically, FIG.
Corresponds to the secondary prediction means, and displays the ranked peptides (P5 in FIG. 3). Specifically,
The processing illustrated in FIG. 14 corresponds to the output unit.

[0045]

As described above, according to the present invention described in each claim, a highly accurate peptide as an antigenic determinant obtained from the primary amino acid sequence of a protein to be analyzed is Furthermore, by selecting a peptide having a high degree of smallness (rare) within a predetermined protein group, it becomes possible to predict a peptide which can be a specific antigenic determinant characterizing the protein to be analyzed. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a computer network system to which a prediction system according to the present invention is applied.

FIG. 2 is a block diagram showing a hardware configuration of a terminal computer system in the computer network system shown in FIG.

FIG. 3 is a flowchart showing a procedure of a process of predicting an antigenic determinant of a protein.

FIG. 4 is a diagram showing a technique for extracting a peptide for determining the suitability of an antigenic determinant from the primary amino acid sequence of a protein.

FIG. 5 is a diagram showing a display example of evaluation values of extracted peptides.

FIG. 6 is a diagram showing a configuration of an antigenic determinant prediction buffer.

FIG. 7 is a diagram illustrating a configuration of a frequency buffer.

FIG. 8 is a diagram showing an input window for obtaining frequency data.

FIG. 9 is a diagram showing a technique for extracting an oligopeptide whose frequency is to be determined from the primary amino acid sequence of a protein.

FIG. 10 is a diagram showing each example of a graph display of the frequency of an oligopeptide extracted by the technique shown in FIG. 9 and a rank display of antigenic determinant specificity.

FIG. 11 is a diagram showing the details of the frequency distribution for the primary amino acid sequence of a protein.

FIG. 12 is a flowchart showing a detailed procedure of a process P4 in FIG. 3;

FIG. 13 is a diagram showing a relationship between a peptide to be evaluated and a peptide to be calculated for frequency.

FIG. 14 is a flowchart showing a detailed procedure of a process P5 in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Control unit 20 Display unit 30 I / O interface 40 Memory unit 50 Input unit 60 CD-ROM driver unit 70 Disk unit 80 Communication unit 100 CD-ROM 110 Host computer system 120 Disk unit 200 (1) -200 (10) Terminal Computer system

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kota Sakai 2-2-1 Hyakuchihama, Sawara-ku, Fukuoka, Fukuoka Prefecture Inside Fujitsu Kyushu System Engineering Co., Ltd. (72) Inventor Hirofumi Doi Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture 4-1-1, Fujitsu Limited

Claims (3)

[Claims] 1. A degree of suitability as an antigenic determinant according to a predetermined algorithm for each peptide composed of a first predetermined number of amino acid residues obtained from primary sequence information of amino acid residues representing a protein to be analyzed. Is determined, a predetermined number of peptides having a high evaluation value are selected, and for each of the selected peptides, the frequency at which a second predetermined number of amino acid residues contained in the peptide appear in a predetermined protein group is determined. The corresponding data is obtained as specificity data indicating the specificity of the peptide, and a peptide that can be a peptide that can be a higher specificity antigen determinant in the protein to be analyzed based on the specificity data is determined. Antigenic determinant prediction method. 2. Evaluating the suitability as an antigenic determinant according to a predetermined algorithm for each peptide composed of a first predetermined number of amino acid residues obtained from primary sequence information of amino acid residues representing a protein to be analyzed. Evaluation value calculating means for quantifying the evaluation result and outputting it as an evaluation value; primary prediction means for selecting a predetermined number of peptides having a high evaluation value obtained by the evaluation value calculation means; and primary prediction means. For each of the selected peptides, a specificity that quantifies data corresponding to the frequency at which a second predetermined number of amino acid residues contained in the peptide appear in a predetermined protein group as specificity data representing the specificity of the peptide Means for calculating the specificity of the protein to be analyzed based on the specificity data obtained by the specificity data calculating means. A secondary estimating means for estimating a peptide that can be had antigenic determinant, antigenic determinants prediction system of a protein and an output means for outputting the peptides predicted by the secondary prediction means together with the specificity data. 3. The protein antigenic determinant prediction system according to claim 2, wherein the specificity data calculating means is configured to generate a predetermined number of amino acid residues for every second predetermined number of amino acid residues obtained from the primary amino acid sequence of the protein to be analyzed. A frequency data receiving unit that receives the frequency of occurrence of the amino acid residue from an external unit in the protein group, and a frequency data receiving unit that determines the frequency of the second predetermined number of each amino acid residue contained in each of the peptides. An antigenic determinant prediction system, comprising: frequency addition means for extracting and adding from a received frequency group, wherein the frequency addition value obtained by the frequency addition means is used as specificity data of each peptide.