koneksony

Fig. 1.11 A ‘ helical wheel’ representation of an amphipathic helix. Each residue is represented by a sphere, and the view is along the helix. Side chains with a particular character (e.g. hydrophilic) will linę one face of the helix if they occur with an average peńodicity of 3.5 residues. In this example, grey spheres are shown at residues 1,4, 8 and 11.

Hydropathy plot on the amino acid seąuence of rat livor connexin. Each amino acid residue has been assigned a “hydropathy index” between -4.5 and +4.5, based on its water-vapour partition coefficient and other parameters [Kyte and Doolittle (1982) J. Mol. Biol. 157, 105-132]. The average hydropathy index of every segment of 19 residues is plotted, and the four putative transmembrane helices (Ml to M4) are clearly seen.

EXTRACELLULAR

GAP

Membranę topology of a single subunit of rat liver connexin based on the hydropathy plot in Fig. 1.12. It is likely that the four helices pack together into a compact structure.