Hydrophobicity scales

Hydrophobicity ( hydropathy also ) is a term used in biochemistry for the extent of the hydrophobic effect in molecules. With increasing hydrophobicity, they are referred to as hydrophilic, amphiphilic or hydrophobic.

Properties

The hydrophobicity of small molecules is described by the octanol - water partition coefficient.

Also for the respective nucleic hydrophobicity was determined.

Hydrophobizitätsskalen of proteins

Proteins in both hydrophilic and hydrophobic amino acids are present as the polymer. A cluster of hydrophobic amino acids in a row indicates their presence in the interior of a protein or a transmembrane domain. There are several scales of the hydrophobicity ( and hydropathic index, hydrophobicity ) of amino acids in proteins, as hydropathic indices (in the singular: hydropathic index ) are referred to or Hydrophobizitätsskalen. In some scales cysteine ​​is defined as the most hydrophobic amino acid, because these methods start from the probabilities of the respective amino acids on the surface of a protein and hardly occur disulfide bridges on the protein surface. The different scales can be divided into five categories.

JTT2 the scale indicates a ratio different. From the frequency with which the amino acid occurring in the Transmembranesegmenten divided by the frequency of the amino acid in a large amount of proteins Then there are the Gunnar von Heijne scale, the Kyte and Doolittle scale, the Wimley -White scale, the scale Aww, the Eisenberg consensus scale and the Engelman - Steitz scale.