Structural organization in feather keratin

Abstract

X-ray diffraction patterns have been obtained from seagull-feather rachis both in the native and partially degraded states. An analysis of these patterns shows that they are consistent with the notion that the fibrous protein in feather keratin is organized into microfibrils and that the microfibrils consist of helical arrays of β-crystallites. It is suggested that the microfibril contains two such helices each of pitch 95 Å with four crystallites per turn and possibly related by a twofold rotation axis perpendicular to the helix axis. An examination of the diffraction properties of the “β-helix” model for feather keratin proposed by Krimm & Schor (1956) suggests that it is not compatible with the observed data.