Modelling of interhelical contacts in interferons-beta, -gamma, and dimeric interleukin-5.

On the basis of crystallographic data, the alpha-helices of interferon-beta as well as each domain of interferon-gamma are located in two layers. This results in a different contribution from the amino acids placing in the middle and border alpha-helices of the layer to the hydrophobic core of the molecule. A close analysis of the structure of dimeric interleukin-5 shows related arrangements of alpha-helices. The full schemes of the interhelix contacts of interferons-beta, -gamma, and dimeric interleukin-5 were constructed. Schemes for interleukin-5 show that extension of helices correlates with the dimer topology.