User:Stephen Mills/Peptide tutorial 2: Difference between revisions
(17 intermediate revisions by the same user not shown) | |||
Line 4: | Line 4: | ||
Identify each amino acid in this dipeptide. | Identify each amino acid in this dipeptide. | ||
<Structure load='CysAsp3.pdb' size=' | <Structure load='CysAsp3.pdb' size='400' frame='true' align='left' caption='Second Dipeptide' scene='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysaspstart/1' name='CysAsp'/> | ||
What is the short-hand notation for this dipeptide? | What is the short-hand notation for this dipeptide? | ||
Click here to show the labels on each amino acid. | <scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysasplabels/2' target='CysAsp'>Click here to show the labels on each amino acid.</scene> | ||
Identify which amino acid is at the N-terminus and which is at the C-terminus. | Identify which amino acid is at the N-terminus and which is at the C-terminus. | ||
Click here to label each terminus. | <scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysasptermini/1' target='CysAsp'>Click here to label each terminus.</scene> | ||
Identify the α carbons of each amino acid. | Identify the α carbons of each amino acid. | ||
Click here to have them highlighted. | <scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysaspalphas/1' target='CysAsp'>Click here to have them highlighted.</scene> | ||
Identify the atoms involved in the peptide bond in this dipeptide. | Identify the atoms involved in the peptide bond in this dipeptide. | ||
Click here to have those atoms change color. | <scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysaspamide/1' target='CysAsp'>Click here to have those atoms change color.</scene> | ||
Now, measure the distance between the α carbons. | Now, measure the distance between the α carbons. | ||
<scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Cysaspmeasure/1' target='CysAsp'>Click here to get a good starting configuration.</scene> | |||
To measure a distance, Double click on the first atom, then double click on the second atom. You may need to rotate the molecule a bit to see the distance well. Try it now. | |||
'''Write down this distance and submit it to your instructor.''' | |||
<br/><br/><br/><br/><br/><br/><br/><br/><br/><br/> | |||
==Oligopeptides== | |||
Now you are ready to work with oligopeptides, or polymers composed of 3-20 amino acid residues. These polymers are linear; that is, each amino acid is linked to it's neighbor in a head-to-tail fashion rather than forming branched chains. You will be observing a 5mer in this tutorial. | |||
<Structure load='GDCRY.pdb' size='500' frame='true' align='left' caption='' scene='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Pentapeptide_start/1' name='penta'/> | |||
For this part, you may need to resize and move the molecule around. To remind you:<br/> | |||
To Rotate: left drag<br/> | |||
To Zoom: scroll button or shift + left drag<br/> | |||
To Translate: ctrl + right drag (On a Mac, this doesn't work in FireFox, but does work in Safari).<br/> | |||
'''Identify where Y and R are located in this oligopeptide.''' | |||
<scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Pentapeptide_yr/2' target='penta'>Click here to have Y and R colored purple.</scene> | |||
Notice that the NH of Y is bonded to the carbonyl of R. | |||
Also notice how the bulky side-chains point away from the backbone of the peptide. | |||
'''Identify where C and D are located in this peptide.''' | |||
<scene name='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Pentapeptide_cd/2' target='penta'> | |||
Click here to have C and D colored purple.</scene> | |||
Notice how Cysteine's thiol (SH) group points outward from the 5mer backbone at an angle that would allow for the stable formation of the disulfide bond.<br/> | |||
'''Identify the remaining amino acid in this peptide.'''<br/> | |||
'''Write down the short-hand notation for this pentapeptide, in the correct order from the N-terminus to the C-terminus and submit this to your instructor.''' | |||
<br/><br/><br/><br/><br/><br/><br/><br/> | |||
==Last Part!!== | |||
Now a test peptide. | |||
<Structure load='WHENISPIEDAY3.pdb' size='600' frame='true' align='left' caption='' scene='User:Stephen_Mills/Sandbox_2_Peptide_tutorial_2/Test_peptide/1' /> | |||
'''Identify the sequence of this peptide and submit the answer to your instructor.'''<br/> | |||
You will probably need to move the molecule around and rotate it to see the whole structure. | |||
When you write down the sequence in the one letter codes, it will spell out a question. | |||
'''Submit the sequence of the peptide '''''and''''' the answer to the question''' | |||
<br/><br/><br/><br/> | |||
'''Congratulations! You have just finished the first Biochemistry Tutorial''' | |||
[[User:Stephen_Mills/Biochemistry_Tutorials|Click here to go back to the main Tutorial page.]] |