Molecular modeling method and system

• US 5,583,973 A
• Filed: 09/17/1993
• Issued: 12/10/1996
• Est. Priority Date: 09/17/1993
• Status: Expired due to Term

• Current Assignee: Boston University
• Original Assignee: Trustees of Boston University
• Inventors: Silverman, Michael D., King, Benjamin L., DeLisi, Charles, Cornette, James L.
• Primary Examiner(s): Herndon, Heather R.
• Assistant Examiner(s): BUCHEL JR, RUDOLPH JOHN
• Application Number:
  US08/123,556
• Time in Patent Office: 1,180 Days
• Field of Search: 395/118-120, 364/468, 364/474.24, 434/277, 434/2-82
• US Class Current: 345/420
• CPC Class Codes: G06T 15/00 3D [Three Dimensional] image rendering
• CPC Class Codes: G06T 15/405 using Z-buffer
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects

Abstract

A method, performed on a computer (10), for generating representations of a molecule, both two- and three-dimensional, is provided. The method includes establishing X, Y, and Z coordinate axes for the molecule to be modeled such that a rectangular region is established with sides parallel to the coordinate axes. The method also includes establishing a grid of coordinates on the X, Y, and Z coordinates axes with a grid mesh size of sufficient resolution to identify atom points of the molecule and solvent points. Next, the method includes identifying surface points which form a trace in one dimension in each Z cross-section, and generating tracing instructions for each Z cross-section by tracing along the surface points in the trace in each Z cross-section and writing the X, Y coordinates to instructions for controlling a computer display or for controlling a computer controlled milling machine. The method also includes generating on a computer display a two-dimensional grid and surface geometry for the molecule including atom identifications using the tracing steps for each Z cross-section. Additionally, the method includes cutting sheets representative of each Z cross-section with the milling instructions and assembling the sheets into three-dimensional models representative of the molecule.

Claims

1. A method for generating a three-dimensional model of a molecule, comprising the steps of:

establishing X, Y, and Z coordinate axes for the molecule to be modeled such that a rectangular region is established with sides parallel to the coordinate axes;

establishing a grid of coordinates on the X, Y, and Z coordinate axes with a grid mesh size of sufficient resolution to identify atom points of the molecule and solvent points;

identifying for each point in the rectangular grid an identity as an atom point, a solvent point, or an empty space point, labeling each point with a representative identifier, and storing the representative identifiers in a three-dimensional character array;

identifying an important component of a solvent region at a grid point within said solvent region and combining said grid point with all grid points that can be connected to it with a chain of adjacent solvent grid points;

identifying surface points which form a trace in one dimension in each Z cross-section;

generating milling instructions for each Z cross-section by tracing along the surface points in the trace in each Z cross-section and writing the X, Y coordinates to instructions for controlling a computer controlled milling machine;

storing the tracing steps for each Z cross-section and correlated machine instructions;

labeling surface points on sheets with representative identifiers at points corresponding to the identified points in the rectangular grid;

retrieving the stored machine instructions and cutting the sheets representative of each Z cross-section with the milling instructions and the computer controlled milling machine; and

assembling the sheets, including aligning exposed representative identifiers, into labeled three-dimensional models representative of the molecule.

2. The method of claim 1, further comprising the steps of:

converting the character array of each Z cross-section into a color picture depicting the number and atom identification of each atom and solvent region; and

assembling said pictures with the sheets to show atom location and identity.

3. The method of claim 1, wherein the molecule is a protein.

4. The method of claim 1, wherein the molecule is a polynucleotide.

5. The method of claim 1, wherein the X-coordinates and Y-coordinates of surface points are stored in respective two-dimensional arrays, with the X, Y coordinates of the surface points located by tracing along a single Z cross-section stored in a single column of each array, said column identifying the Z coordinates in each array.

6. The method according to claim 5, wherein said two separate two-dimensional arrays are used to compute a Gaussian curvature of the surface, and storing said curvature in a third two-dimensional array.

7. The method according to claim 6, wherein the third two-dimensional array is converted into a picture showing cavities in the surface.

8. The method according to claim 1, wherein each surface point is identified with the nearest atom of the molecule, and storing said identification in a two-dimensional array, with the identity associated with the surface points identified by tracing along a single Z cross-section being stored in a single column of the array.

9. The method according to claim 8, further comprising the step of identifying all the surface points associated with a single atom, locating the centroid of those surface points, and generating an identifying atom label attached to that centroid.

10. A method for generating a two-dimensional representation of the surface of a molecule, comprising the steps of:

establishing X, Y, and Z coordinate axes for the molecule to be modeled such that a rectangular region is established with side parallel to the coordinate axes;

establishing a grid of coordinates on the X, Y, and Z coordinates axes with a grid mesh size of sufficient resolution to identify atom points of the molecule and solvent points;

identifying for each point in the rectangular grid an identity as an atom point, a solvent point, or an empty space point, labeling each point with a representative identifier;

identifying an important component of a solvent region at a grid point within said solvent region and combining said grid point with all grid points that can be connected to it with a chain of adjacent solvent grid points;

identifying surface points which form a trace in one dimension in each Z cross-section;

generating tracing instructions for each Z cross-section by tracing along the surface points in the trace in each Z cross-section and writing the X, Y coordinates to instructions for controlling a computer display; and

generating on a computer display a two-dimensional grid and surface geometry for the molecule including representative identifiers using the tracing steps for each Z cross-section.

11. The method of claim 10, wherein the molecule is a protein.

12. The method of claim 10, wherein the molecule is a polynucleotide.

13. The method according to claim 10, wherein each surface point is identified with the nearest atom of the molecule, and storing said identification in a two-dimensional array.

14. The method according to claim 13, further comprising the step of identifying all of the surface points associated with a single atom, locating the centroid of those points, and generating an identifying atom label attached to that centroid.

15. A system for generating a model of a molecule, comprising:

circuitry operable to establish a X, Y, and Z coordinate axes for the molecule to be modeled such that a rectangular region is established with sides parallel to the coordinate axes;

circuitry operable to establish a grid of coordinates on the X, Y, and Z coordinate axes with a grid mesh size of sufficient resolution to identify atom points of the molecule and solvent points;

memory operable to store the X, Y, and Z coordinate axes, cross-sections, and grid;

a processor operable to retrieve from memory the X, Y, and Z coordinate axes, correlated Z cross-sections, and grid and identify for each Z cross-section atom points, solvent points and empty space points in the grid, to identify an important component of a solvent region at a grid point within said solvent region and combining said grid point with all grid points that can be connected to it with a chain of adjacent solvent grid points, to label the atom and solvent points with representative identifiers, and store in said memory in a three-dimensional character array the representative identifiers;

wherein said processor is operable to identify surface points which form a trace in one dimension in each Z cross-section; and

a computer display to display a two-dimensional grid and surface geometry for the molecule including representative identifiers using the tracing steps for each Z cross-section.

16. A system according to claim 15, further comprising:

a computer controlled milling machine and a computer controlled sheet marker;

wherein said processor is further operable to generate milling instructions for each Z cross-section by tracing along the surface points in the trace in each Z cross-section and writing the X, Y coordinates to instructions to control said computer controlled milling machine;

wherein said processor is further operable to store in said memory the trace steps for each Z cross-section and correlated machine instructions;

wherein said sheet marker is operable to label surface points on sheets with representative identifiers at points corresponding to the identified points in the rectangular grid; and

wherein said milling machine is further operable to the cut sheets representative of each Z cross-section with the milling instructions.

17. A system according to claim 15 wherein the molecule is a protein.

18. A system according to claim 15 wherein the molecule is a polynucleotide.