A 47aa dermcidin (DCD)-derived peptide (DCD(63-109), also known as as DCD-1) is an antimicrobial peptide with a negative net charge and acidic pI (Schittek B 2012). Like other antimicrobially active DCD-derived peptides, DCD(63-109) is produced in human eccrine sweat through proteolytic processing of a 110-amino acid (aa) precursor protein (Schittek B et al. 2001; Rieg S et al. 2006). DCD-derived peptides are able to bind to the bacterial surface, however they do not exert their activity by permeabilizing bacterial membranes (Senyürek et al. 2009, Steffen H et al. 2006). The negative net charge of DCD(63-109) did not significantly affected the peptide binding to bacterial-mimetic membranes (Jung et al. 2010, Steffen et al. 2006; Senyurek et al. 2009). Spin-down assays of DCD(63-109) and other DCD peptides revealed that the affinity with which dermcidin binds to bacterial-mimetic membranes is primarily dependent on its amphipathic alpha-helical structure and its length (>30 residues)(Jung et al. 2010).
DCD(63-109) shows a broad spectrum of antimicrobial activity against Gram-positive (Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Listeria monocytogenes) and Gram-negative bacteria (Escherichia coli, Pseudomonas putida, Salmonella typhimurium) as well as Candida albicans (Cipakova I et al. 2006, Lai YP et al. 2005, Schittek B et al. 2001, Steffen H et al. 2006, Vuong C et al. 2004). The activity of the DCD(63-109) was maintained over a broad pH range and in high salt concentrations that resembled the conditions in human sweat (Schittek B et al. 2001).