Fig. 1

SDS-PAGE separation of nacre and prismatic layer organic matrix proteins. S, acid-soluble; I, acid-insoluble. 200 μg of matrix were applied to each lane. Nacre acid-soluble matrix and prismatic layer acid-insoluble matrix were cut into sections for in-gel digestion as indicated. At the left the masses of marker proteins are shown in kDa (Novex Sharp pre-stained, Invitrogen)