Expression of a triple mutational des-pGlu brazzein in transgenic mouse milk

Abstract

Brazzein has excellent potential for use as a sweetener because of its high level of sweetening potency and stability against extreme temperature and pH. It is extracted from the tropical and difficult—to-cultivate African plant Pentadiplandra brazzeana, which hampers its commercial viability. Here we report the mammary-specific expression of wildtype or triple mutational (H31R/E36D/E41A) des-pGlu brazzeins in the milk of transgenic mice. Using enzyme-linked immunoassay (ELISA), western blot, and sweetness intensity testing, we confirmed that the triple mutation made the des-pGlu brazzein molecule 10,000 times sweeter than sucrose in a weight base, even after 10 min of incubation at 100 °C; in addition, the triple mutant was also significantly sweeter than the wildtype des-pGlu brazzein. This study provides new insights for producing brazzein or brazzein-sweetened milk from animals for use in food and healthcare applications.