HIGHLY-EXPRESSED S100A3, A CALCIUM-BINDING PROTEIN, IN HUMAN HAIR CUTICLE

Analyses on sodium dodecyl sulfate-polyacrylamide gel electrophoreses showed that the human hair cuticle extracts mainly consist of a 7-kDa component and keratin proteins. The S-carboxymethylation of the cuticl e extracts made the 7-kDa band shift to the 15-kDa position. After ele ctroblotting of the S-carboxymethyl derivative, the membrane pieces ca rrying the 15-kDa band were treated with trypsin and the released pept ides were separated by reverse-phased HPLC. Amino acid sequence analys es revealed that the peptides corresponded to the partial sequences de duced from human genome coding for S100A3, a cysteine-rich calcium bin ding protein. The anti S100A3 serum, prepared by immunizing a syntheti c peptide antigen, reacted with the 7-kDa and 15-kDa bands in immunobl otting analyses. Immunofluorescence microscopy showed intense labeling to the cuticular layer with the anti S100A3 serum. These results indi cated that S100A3 was highly expressed in the human hair cuticle.