Identification of a 37 kilodalton protein at the epidermal basement membrane by an antiserum to human amnion.

A protein which is recognized by an antibody to human amniotic epithelial basement membrane was identified at the basal lamina of human epidermis by immunohistology. This protein was localized at the lamina lucida of human epidermal basement membrane by immunoelectron microscopy. Studies of normal human keratinocyte cultures and epidermal wound healing suggested that the protein was probably produced by keratinocytes. By immunoblotting, a basic apparent isoelectric pH (pHiapp = 7.3) protein band of 37 kD was seen. These data indicate that this 37 kD protein, clearly different from other known basement membrane components, is present in simple and stratified epithelia of ectodermal origin, and is associated with hemidesmosomes.