PROTEINS OF HAIR 93 AMINO ACID ANALYSIS Hair samples were hydrolyzed in vacuo with constant boiling HCI at 108øC for 22 h and freeze dried. The hydrolysate was adjusted to pH 7.8 and shaken with air to oxidize cystine. The content of amino acids was estimated with a modified Beckman (- 120C) amino acid analyzer. RESULTS ELECTROPHORETIC PATTERNS OF ALKYLATED PROTEINS EXTRACTED FROM A EUROPEAN BROWN HAIR The SDS-PAGE electrophoretic pattern of SCM proteins extracted from Caucasian brown hair is shown in Figure lb. It displays two major groups of bands: The first group corresponds to the LSP and consists of five polypeptides with molecular weights ranging from 75 Kd to 35 Kd. The second group contains the HSP which are resolved in eight bands ranging from 30 Kd to 14 Kd. The 2-D analysis (Figure la) shows six spots of LSP proteins and eight spots of HSP. At pH 8.9, HSP are characterized by a higher mobility than LSP. Figures la and lb will serve as reference patterns. ELECTROPHORETIC PATTERNS OF SCM PROTEINS FROM WEATHERING HAIRS The brown hair exposed (as reference) to prolonged daylight exposure shows a marked decrease of 87% of solubilized protein yield and only exhibits HSP after electrophoretic analysis (Figure 2a). Figure 1. Autoradiographies of two-dimensional electrophoresis (la) and SDS-PAGE (lb) of alkylated proteins extracted from European brown hair.

94 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 2. Autoradiographies of mono- and bidimensional electrophoresis of alkylated proteins extracted from prolonged weathered hair (a), proximal root part (b), and distal end part (c) of Caucasian brown hair. The protein extracted from the proximal part of normally exposed brown hair has a better solubility (12.6%) than the median (7.2%) and distal (8%) part of hair (Table I). The electrophoretic pattern of the proximal part (Figure 2b) shows the same profile as