Manavalan P, Swope D L, Withy R M
Genzyme Corporation, Framingham, Massachusetts 01901.
J Protein Chem. 1992 Jun;11(3):321-31. doi: 10.1007/BF01024870.
The sequences of nine different cytokines, growth hormone, and prolactin have been aligned and their secondary structure predicted. The alignment reveals that each exon has a characteristic sequence pattern shared by all cytokines. The most striking sequence similarity is observed in exon 4, where the residue pair Phe-Leu is conserved in many cytokines. In addition, there are discreet homologous regions between two specific growth factors, including a high degree of homology between granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3). The secondary structure analysis predicts that exon 3 of all cytokines has an antiparallel helix-turn-helix motif, which is likely to form the central helical segments of a four alpha-helical bundle-type structure. Based on the secondary structure and the disulfide-bonding pattern, the topological connectivity for a number of cytokines has been predicted.
