Each protein is identified by a unique sequence of amino acids, the primary structure of the protein.
The table below shows the 20 amino acids used in Foldit. Clicking on the arrows in the column heads changes the sort order of the table. The table is explained in detail below.
|Amino Acid||3-Letter||1-Letter||Hydrophobicity /||polarity||acidity (pH)|
|Aspartate (aspartic acid)||Asp||D||-3.5||polar||acidic|
|Glutamate (glutamic acid)||Glu||E||-3.5||polar||acidic|
See the amino acid gallery for examples of what each amino acid looks like in Foldit.
See proteinogenic amino acid on wikipedia for more information about each amino acid.
The table shows how amino acids are identified and lists the key characteristics of their sidechains.
The first column shows each amino acid's full name, and links to its detail page.
Two amino acids have two names. Aspartate is also called aspartic acid, and glutamate is also called glutamic acid. This is because both have acid sidechains.
Some sources, such as the PDB, use three-letter codes to represent amino acids.
One important characteristic of an amino acid is how it interacts with water, also known as hydrophobicity. In Foldit, an amino acid is either hydrophilic, meaning it likes water, or hydrophobic, meaning it tries to avoid water. The hydropathy index is a more refined version of this idea.
The hydropathy index values shown in blue are for amino acids classified as hydrophilic in Foldit. The values shown in orange are for amino acids considered hydrophobic. In general, negative values are hydrophilic in Foldit, and positive values are hydrophobic. There are several exceptions in the middle of the table, however.
The amino acids listed as "polar" have sidechains with nitrogen or oxygen atoms that can form hydrogen bonds. See sidechain bonding gallery and sidechain bonding table for details on the bondable atoms
The sidechain of each amino acid is classified as acidic, basic, or neutral.