The cornified cell envelope (CE) is a 15-nm thick layer of insoluble protein deposited on the
intracellular side of the cell membrane of terminally differentiated stratified squamous
epithelia. The CE is thought to consist of a complex amalgam of proteins cross-linked by
isodipeptide bonds formed by the action of transglutaminases, but little is known about how
or in which order the several putative proteins are cross-linked together. In this paper, CEs
purified from human foreskin epidermis were digested in two steps by proteinase K, which …