Peptide derived from saliva may fight AIDS-related fungal infections

Researchers at the University of Buffalo in New York have developed a peptide from a salivary protein that appears to have significant antifungal activity against candidiasis, or thrush, a common oral fungal infection among HIV patients, AIDS Weekly reports. "We found that a peptide called MUC7 12-mer-D, a small piece of the parent human salivary protein mucin, killed 92% of the fungal agent Candida albicans in saliva in vitro," said lead researcher Libuse Bobek, professor of oral biology at the University of Buffalo School of Dental Medicine. Most peptides suffer enzyme degradation in saliva, which renders them less active or inactive, but that doesn't happen with the peptide developed by Bobek's team. The researchers tested the peptide's activity against Candida albicans and compared the compound's effects to another peptide that is effective against the fungus but loses its efficacy when exposed to saliva. The peptide developed by Bobek's team killed 96% of the fungus in a saliva solution compared with just 56% killed by the other compound tested. The new peptide also was shown to be much less toxic than other peptide treatments, causing little red blood cell destruction even at high concentrations, a common sign of toxicity. Animal tests are now planned.