Polar (may participate in hydrogen bonds):
• Glutamine - Gln
• Asparagine - Asn
• Histidine - His
• Serine - Ser
• Threonine - Thr
• Tyrosine - Tyr
• Cysteine - Cys
• Methionine - Met
• Tryptophan - Trp
Hydrophobic (normally buried inside the protein core):
• Alanine - Ala
• Isoleucine - Ile
• Leucine - Leu
• Phenylalanine - Phe
• Valine - Val
• Proline - Pro
• Glycine - Gly
Charged: ******Are usually found close to the surface
• Arginine - Arg
• Lysine - Lys
• Aspartic acid - Asp
• Glutamic acid - Glu
In this problem, 6 amino acids have been randomly selected from the 129 amino acids in lysozyme; they are shown as solid spheres. The remainder of the protein is shown as a cloud of tiny dots.
Your task is to find out which of the 6 amino acids are on the surface of the protein and which are on the interior of the protein.
For each of these amino acids, fill in the table as appropriate:
Leucine (Leu) 56 Arginine (Arg) 21 Asparagine (Asn) 39 Arginine (Arg) 5 Arginine (Arg) 128 Tyrosine (Tyr) 20
Inside
Outside
Hydrophobic
Hydrophilic
Inside
Outside
Hydrophobic
Hydrophilic
Inside
Outside
Hydrophobic
Hydrophilic
Inside
Outside
Hydrophobic
Hydrophilic
Inside
Outside
Hydrophobic
Hydrophilic
Inside
Outside
Hydrophobic
Hydrophilic
Hint: The dots are your most useful clue, if you can see all or part of an amino acid without any dots on it, then that amino acid is (at least partly) on the surface of the protein. If you can not see the amino acid without dots on it in any orientation, then that amino acid is on the inside. Remember that you can identify an amino acid by leaving the cursor over any of the atoms in that amino acid. This is shown below:
An "Inside" example An "Outside" example
Notice that all of the atoms in the highlighted amino acid are covered with dots representing other atoms in the protein. Notice that, although some highlighted atoms are covered with dots representing other atoms in the protein, many of the highlighted atoms are visible without dots on them.
1 answer
1 answer