Amino Acid Hydrophobicity

In Chimera, amino acid residues are automatically assigned an attribute named kdHydrophobicity, with values according to the hydrophobicity scale of Kyte and Doolittle.

Other hydrophobicity scales are not assigned automatically, but input files to define wwHydrophobicity and hhHydrophobicity with Define Attribute are linked below. A simple text format allows users to create custom attributes with ease.

Residue Type kdHydrophobicitya wwHydrophobicityb hhHydrophobicityc
Ile 4.5 0.31 -0.60
Val 4.2 -0.07 -0.31
Leu 3.8 0.56 -0.55
Phe 2.8 1.13 -0.32
Cys 2.5 0.24 -0.13
Met 1.9 0.23 -0.10
Ala 1.8 -0.17 0.11
Gly -0.4 -0.01 0.74
Thr -0.7 -0.14 0.52
Ser -0.8 -0.13 0.84
Trp -0.9 1.85 0.30
Tyr -1.3 0.94 0.68
Pro -1.6 -0.45 2.23
His -3.2 -0.96 2.06
Glu -3.5 -2.02 2.68
Gln -3.5 -0.58 2.36
Asp -3.5 -1.23 3.49
Asn -3.5 -0.42 2.05
Lys -3.9 -0.99 2.71
Arg -4.5 -0.81 2.58

a A simple method for displaying the hydropathic character of a protein. Kyte J, Doolittle RF. J Mol Biol. 1982 May 5;157(1):105-32.

b Experimentally determined hydrophobicity scale for proteins at membrane interfaces. Wimley WC, White SH. Nat Struct Biol. 1996 Oct;3(10):842-8. Attribute assignment file wwHydrophobicity.txt.

c Recognition of transmembrane helices by the endoplasmic reticulum translocon. Hessa T, Kim H, Bihlmaier K, Lundin C, Boekel J, Andersson H, Nilsson I, White SH, von Heijne G. Nature. 2005 Jan 27;433(7024):377-81, supplementary data. Attribute assignment file hhHydrophobicity.txt. In this scale (unlike the others), more negative values reflect greater hydrophobicity.


UCSF Computer Graphics Laboratory / June 2010