The narrow selectivity filter is only 12 angstroms long, whereas the remainder of the pore is wider and lined with hydrophobic amino acids. (science.sciencemag.org)
The protein structure of the hard keratins such as wool is predominately hydrophobic amino acids coupled with a high lipid percentage lending a waterproof characteristic to the wool fiber. (tandemtrouble.com)
The signal - sequences are highly diverse in both length and in amino - acid composition but they all have a core of at least eight consecutive hydrophobic amino acids that acts as the major determinant for recognition by SRP. (sciencedaily.com)