Keratin adducts

Noort, D., Fidder, A., Hulst A.G., De Jong L.P., Benschop, H.P. (2000). Diagnosis and dosimetry of exposiue to sulfur mustard development of a standard operating procedure for mass spectrometric analysis of haemoglobin adducts exploratory research on albumin and keratin adducts. J. Appl. Toxicol. 20 SI 87-92. 

Skin Keratin adducts Alkaline hydrolysis, derivatization LC/radiometric detector Not reported Noort et al. (2000a)... 

G.P. Van der Schans, D. Noort, R.H. Mars-Groenendijk, A. Fidder, L.F. Chau, L.P.A. De Jong and H.P. Benschop, Immunochemical detection of sulfur mustard adducts with keratins in the stratum corneum of human skin, Chem. Res. Toxicol., 15, 21-25 (2003). 

The use of sulfur mustard as a vesicant CW agent implies that proteins of the skin are a primary target. It was found that upon exposure of human callus to [14C]sulfur mustard, a significant part of the radioactivity was covalently bound to keratin (30). Most of the radioactivity (80%) bound to keratin could be removed by treatment with alkali, indicating the presence of adducts to glutamic and/or aspartic acid residues. 

A direct detection method was recently developed for these adducts in stratum comeum of human skin based on immunofluorescence microscopy (30). Three partial sequences of keratins containing glutamine or asparagine, adducted with a 2-hydroxyethyl-thioethyl group at the omega-amide function, were synthesized and used as antigens for raising antibodies. After immunization, monoclonal antibodies were obtained with affinity for keratin isolated from human callus exposed to 50 xM sulfur mustard (see Plate 1). In contrast to the immunochemical... 

Figure 4. Immunofluorescence microscopy of a cross-section of human skin exposed to saturated sulfur mustard vapor (1 min at 27 °C Ct 1040 mg.min.nr3 A) and of unexposed skin (B), using monoclonal antibody 1H10, directed against sulfur mustard adducts to human keratin, in a 1/50 dilution. The photographs are composed from an image obtained for FITC fluorescence (mainly emanating from the stratum corneum green) and from an image obtained for propidium iodide fluorescence representing DNA (red) in the same cross-section. (Reprinted with permission from G. R van der Schans et al., Chem. Res. Toxicol. 15, 21-25, 2002. Copyright (2002) American Chemical Society).

Antibodies against adducts of sulfur mustard to keratin in the skin are available which opens the way for the development of an assay for in situ detection of sulfur mustard exposure of human skin. 

Recently, local adduct formation after cutaneous exposure to sulfur mustard has been a focus of investigation in an effort not only to establish new forensic methods, but also to better understand vesication, the most evident symptom of sulfur mustard exposiue via the skin. Adducts of sulfur mustard to cytokeratin types 1 and 11, actin stratifin, and galectin-7 were successfully identified by Mol et al. (2008) in sulfur mustard-exposed human epidermal keratinocytes. Sulfur mustard adducts to actin, annexin A2, and keratin 9 were also found in HaCaT cells (immortalized kerationcytes) by Sayer et al. (2009). 

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