Studies on microfibrils from alpha-keratin.

alpha-Keratin microfibrils have been isolated from the presumptive cortex of developing mammalian hair follicles and purified by a centrifugation procedure. They have been obtained on a scale sufficient to enable their physical and chemical nature to be studied directly. The amino acid and protein compositions of the microfibril preparation closely resemble those of the low-sulphur protein fraction extracted from the fully keratinized fibre. High resolution electron microscopy of isolated microfibrils has indicated that they possess structural features in line with those observed in sectioned material.