Main Page Background Info Entry Form Links

Amino Acid Hydropathy Scores
Amino Acid Name
One Letter Code

Hydropathy Score

Isoleucine I 4.5
Valine V 4.2
Leucine L 3.8
Phenylalanine F 2.8
Cysteine C 2.5
Methionine M 1.9
Alanine A 1.8
Glycine G -0.4
Threonine T -0.7
Tryptophan W -0.9
Serine S -0.8
Tyrosine Y -1.3
Proline P -1.6
Histidine H -3.2
Glutamic acid E -3.5
Glutamine Q -3.5
Aspartic acid D -3.5
Asparagine N -3.5
Lysine K -3.9
Arginine R -4.5

These scores are based on the values given by the original Kyte-Doolittle paper.  Other scoring systems have been determined and are used in other hydropathy plots.  See, for example a web site about experimentally determined hydrophobicity scales


Kyte, J. and Doolittle, R. 1982. A simple method for displaying the hydropathic character of a protein. J. Mol. Biol. 157: 105-132.