Enamel proteins within two preferentially used animal models.
Two different models have been used to study enamel proteins: rodent incisors and bovine or porcine tooth germs. In the present experiment proteins were sequentially extracted from forming enamel of rat incisors and bovine tooth germs and examined using SDS-PAGE. The Coomassie-blue staining of amelogenins from both species revealed very similar patterns, which indicates a rather common processing, although developed at different rates. Non-amelogenin proteins behave differently when Concanavalin-A probing was used. Bovine non-amelogenins contain amido-black stainable proteins which are not recognized by lectin, contrary to rat enamel. If those proteins are albumin or albumin derived, as recently suggested, the observed discrepancy might be explained by the non enzymatic glycation known to occur on circulating albumin. In that case it would be a consequence of the use of adult rats in which circulating albumin is partly glycated versus bovine foetuses in which albumin would not be significantly glycated. Finally both species contain glycoproteins within non-amelogenins, which remain to be more precisely defined.