John Brahms

Detection and quantification of apocrine secreted odor-binding protein on intact human axillary skin.

A proposed mechanism of axillary malodor formation is bacterial interaction with secreted odor carrier proteins leading to the release of volatile odor molecules. One primary volatile odor molecule, 3‐methyl‐2‐hexenoic acid, is secreted into the apocrine glandular lumen bound to two carrier proteins known as apocrine secretion odor‐binding proteins (ASOB1 and ASOB2). The objective of this study was to develop a biologic method to detect and quantify ASOB2 in vitro and on intact axillary skin. The proteins present in pure apocrine secretion were separated via SDS–polyacrylamide gel electrophoresis (PAGE), electro‐blotted, and reacted with antibodies to detect ASOB2. The results of this study demonstrate that ASOB2 shares immunologically homologous epitopes with the human serum protein, apolipoprotein‐D (apo‐D). Axillary secretions and baseline microflora were collected from two groups of panelists 6 h after showering with a non‐antibacterial soap. The extracts were fractionated by SDS–PAGE. ASOB2 was detected selectively by Western blot using a monoclonal mouse‐antihuman apo‐D antibody and quantified on human axillary skin using the presented methods. Axillary ASOB2 concentration varied among individuals (<0.1–4.1 µg cm−2) with significant differences (P < 0.05, anova) seen between those of Chinese descent and non‐Chinese descent. Panelists of Chinese ancestry did not show significantly lower baseline microflora levels when compared to non‐Chinese panelists.