Concanavalin (ConA)-reactive human epidermal glycoproteins.

The possibility that glycoconjugates play a role in epidermal differentiation has stimulated attempts at their biochemical identification. We have examined the Concanavalin (ConA)-binding glycoproteins present: in whole human epidermis, epidermal cells obtained by trypsinization of human skin, non dissociated layers (the most differentiated ones) remaining after preparation of these cells and human epidermal cell cultures. 125I-ConA was applied to NP-40 soluble molecules separated by SDS-PAGE. ConA labelling of the whole epidermal extract visualized numerous bands. That of trypsinized cells differed in the intensity of some bands and the absence of others. However most of the latter bands could be identified in the most differentiated layers. These glycoproteins were absent or poorly labelled in the cultures of keratinocytes. The restriction of some ConA-binding glycoproteins to the most differentiated epidermal layers, suggests that these molecules are involved in, or can be considered as markers of the human epidermal differentiative process.