Improved Two-Dimensional Electrophoretic Mapping of Japanese Human Hair Proteins; Application to Curved and Straight Japanese Human Hairs; and Protein Identification by MALDI MS and MS/MS Quadrupole Time-of-Flight Mass Spectrometry

The study evaluated improved protein extraction and two-dimensional electrophoresis (2DE) methods for Japanese human hair (JRH) and examined the relationship between hair curvature and protein composition in Japanese women's hair (JHH). Using tris(2-carboxyethyl) phosphine for protein extraction enhanced keratin and keratin-associated protein (KAP) resolution compared to dithiothreitol. The 2DE gels of straight and curved JHH were similar, with only two proteins showing significant abundance differences, insufficient for mass spectrometry (MS) analysis. MS identified 12 proteins from JRH, including keratins and high sulfur proteins, and suggested multiple isoforms. The study concluded that improved extraction methods enhance protein visualization, but minor protein differences are unlikely to affect hair curvature.