Jmol-Application/C4/3D-Models-of-Enzymes/English
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Slide Number 1
Title Slide |
Hello everyone.
Welcome to this tutorial on 3D Models of Enzymes in Jmol. |
Slide Number 2
Learning Objectives |
In this tutorial, we will learn to
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Slide Number 3
Learning Objectives |
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Slide Number 4
Pre-requisites |
To follow this tutorial you should have
Knowledge of basic biochemistry. And familiar with basic operations from Jmol Application window. Please view the tutorial Proteins and Macromolecules' in the Jmol Application series. Please view the tutorial Proteins and Macromolecules' in the Jmol Application series |
Slide Number 5
System Requirement |
To record this tutorial, I am using
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Cursor on the panel. | Open the Jmol window and load the structure of Hexokinase enzyme. |
Cursor on the panel. | I am connected to internet, so I will load the structure directly from the PDB website. |
Open File menu, Scroll down to Get PDB. | To do so,
Open the File menu, scroll down and click on Get PDB option. |
Cursor on input box.
Type 3IDH in the text box. |
An Input box appears on the screen.
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Cursor on the Jmol panel | This code was obtained from the Protein Data Bank website. |
Click on “open a file option” | If you do not have a working Internet connection:
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Click on OK button.
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Click on OK button.
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Cursor on the panel. | 3D Structure of hexokinase also known as glucokinase opens on the screen. |
Open File menu and click on Console option. | Open the console window using the file menu. |
Open the console window from the file menu. | As shown on the Console:
The structure on the panel is for Human Pancreatic Glucokinase along with substrate Glucose.
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Cursor on the panel | On the panel we have the ball and stick model of hexokinase. |
Cursor on the panel.
Open the pop-up menu by right clicking on the panel. Move the cursor on Select then Scroll down and select “Hetero” from the drop down select “All water” option. Open the pop-up menu again and scroll down to Style, then Scheme, from the drop down select CPK option. Open the pop-up menu again , scroll down to “Style”, then to “Atoms” from the drop down, select “Off” option. |
Remove the water molecules from the protein model on the panel.
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Slide Number 6
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About Hexokinase Enzyme.
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Slide Number 7
Hexokinase |
Active-site for hexokinase has 3 amino acid residues:
Alpha-D-Glucose is the substrate for this enzyme.
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Cursor on Jmol panel. | Now Let us now go back to the Jmol panel. |
Cursor on Jmol panel with the model of Hexokinase.
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We can select and highlight the components of enzymes like :
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Right-click to open the pop-up menu.
Go to 'Select' option. |
To select a particular component:
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From the drop down select Proteins option.
From the submenu select “By Residue name” option. Point to the amino acid residues in the list. For the reviewers Only show and do not click on the name of the “amino acid” |
From the sub-menu, Proteins, select By Residue name.
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Scroll down the submenu for the Protein option. | Also amino acids are grouped under headings like:
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From the “select menu”
Go to Hetero menu, select By HETATM option. Show K-Potassium and GLU-Alfa-D-glucose. |
Listed in the Hetero menu, are the metal ion potassium and substrate glucose. |
Exit the pop-up menu. | We can modify the display of the enzyme to easily locate the substrate binding site. |
Cursor on the panel. | Let us change the display and color of the atoms of the protein. |
Open the Pop-up menu.
Scroll down the Protein option.
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Open the pop-up menu, go to Select, and scroll down to Protein option.
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Open the pop-up menu again,go to Style, then to Scheme.
Click on Sticks option. |
Open the pop-up menu again, scroll down to Style, then to Scheme.
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Cursor on the panel. | Now we have on the panel the protein in sticks display
Now to change the color. |
Open pop-up menu, Scroll down to Color, go to Atoms, click on Blue option. | Open the pop-up menu again, go to Color, Atoms, click on Blue option. |
Cursor on the panel. | We have on the screen the model of Hexokinase in blue color and in sticks display. |
Point out to glucose molecule. | Observe the substrate, Alfa-D-Glucose in ball and stick display in the cleft. |
Open the pop-up menu, go to Select option and scroll down to Hetero.
Click on GLC-Alfa-D-glucose |
To highlight the substrate.
Open the pop-up menu, go to Select, then Hetero and click on GLC-ALFA-D-GLUCOSE. |
Open the pop-up menu, scroll down to Style, select Sticks option. | Open the pop-up menu again , scroll down to Style, Scheme and click on Sticks option. |
Open the pop-up menu, scroll down to Color, then Atoms and click on White option. | To change the color:
Open the pop-up menu again, go down to Color,, Atoms and click on White option. |
Set the model to spin. | On panel is the model of hexokinase with position of the substrate clearly highlighted. |
Cursor on the panel | We can change the color of the amino acids at the active site to highlight them.
To do so, we have to type commands in the console window. |
Cursor on the panel. | As mentioned earlier the amino acids involved at the active-site are
Aspergine at position 204 Aspergine at position 231 and Glutamic acid at 256 |
Open the file menu, scroll down to console and click on it. | Open the console window using file menu. Click on Console.
I am using Kmag Screen magnifier to magnify the console window. |
At the $ prompt type “select [Asn]204; color atoms orange
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At the $ prompt type:
select within square brackets Asn for aspergine close the bracket, 204 i.e the position semicolon color atoms orange.
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Cursor on the panel. | Observe that the atoms of Aspargine residue now in orange color. |
Press the up arrow button on the key board.
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Press up arrow button on the key board.
And edit the command. Edit the amino acid position to 231 and color of atoms to red. |
Delete orange and type red. | Press Enter . |
Press up arrow key .
Delete ASN. Type GLU. Edit the position number to 256. Press enter key. |
Press up arrow key and again and edit name of amino acid to GLU, that is glutamic acid and position to 256.
And color of atoms to green. Press Enter . |
Cursor on the panel
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We have on the panel a 3D model of hexokinase with substrate and the active site highlighted. |
Point at the Potassium ion.
Select potassium (K) from the Select menu and change the color to yellow. |
Also highlighted in the model is the potassium atom.
Shown here in purple color. |
Cursor on Jmol. | We can also show Ramachandran plots for a particular protein in jmol. |
Open the console, at the $ prompt write “plot ramachandran” .
Press Enter key. |
On the console, at the $ prompt type plot ramachandran
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Cursor on the panel. | On the screen we have a ramachandran plot for hexokinase. |
Cursor on the panel. | Try to load different enzymes using pdb files from the database.
Change the display of secondary structure. |
Slide Number 8
Summary |
Lets summarize, In this tutorial we learnt to,
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Slide Number 9
Summary |
* Highlight substrate and cofactors of the enzyme.
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Slide Number 10
Assignment |
As an Assignment:
Hint: Get the pdb file of Lysozyme from PDB database. |
Slide Number 11
Acknowledgement |
Watch the video available at this URL.
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Slide Number 12 | The Spoken Tutorial Project Team:
Conducts workshops and distributes certificates. For more details, please write to us. |
Slide number 13 | Spoken Tutorial Project is a part of the Talk to a Teacher project.
It is supported by the National Mission on Education through ICT, MHRD, Government of India. More information on this Mission is available at this link |
This is Snehalatha from IIT Bombay signing off. Thank you for joining. |