Increased scientific knowledge related to the nutritional, functional and biological activities and health
benefits of goat milk is needed to further promote goat farming, goat milk and traditional or innovative
neutraceuticals as a basis for socio-economic benefit. Identification and characterization of milk derived
Prosaposin is essential to development of neutraceuticals from goat milk that maybe beneficial to human
health. The objectives of this study were to detect Prosaposin and its mature proteins in milk from different
breeds of goats. Raw milk was collected from eight different breeds of goat. Whey fractions were separated
by high speed centrifugation. Extracts were analyzed by electrophoresis using the Pharmacia Phastsystem
(GE Healthcare) in 12.5% homogeneous gels. Gels were silver stained to analyze total protein. Phastsystem
diffusion immunoblotting with HRP enzyme-labeled polyclonal anti-Prosaposin, anti-saposin and a
tetramethylbenzidine substrate was used to identify specific proteins. Multiple proteins were observed in
whey fractions from all animals tested. Antibodies detected a 70-65 kDa Prosaposin band and a 12-14 kDa
saposin C band in all goat breeds. Both Prosaposin and its derivative saposin A, B, C and D were detected
in caprine milk. These studies show that Prosaposin is present in milk from different breeds of goats
contributing to therapeutic attributes of goat milk. The biological activity of saposins such as the
neurotrophic activity of goat saposin C need further characterization.