A Proteomic Study on Donkey Milk
- *Corresponding Author:
- Prof. Silvia Vincenzetti
Veterinary School of Medical Sciences
University of Camerino, Road 93/95 Bypass
62024 Matelica (MC), Italy
E-mail: [email protected]
Received Date: December 05, 2011; Accepted Date: February 01, 2012; Published Date: February 03, 2012
Citation: Vincenzetti S, Amici A, Pucciarelli S, Vita A, Micozzi D, et al. (2012) A Proteomic Study on Donkey Milk. Biochem Anal Biochem 1:109. doi:10.4172/2161-1009.1000109
Copyright: © 2012 Vincenzetti S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
In children with Cow Milk Protein Allergy (CMPA), when it is not possible to breast feed or to use cow milk, the clinical use of donkey milk is considered since several studies have demonstrated the high similarity of donkey milk compared to human milk.
An analysis was performed on donkey milk protein profile by two-dimensional electrophoresis (2-DE) followed by N-terminal sequencing in order to give a panoramic view of the proteins that are present in donkey milk. Furthermore, the interest was focused on the casein fractions and on their phosphorylation degree that may influence the calcium binding ability of caseins. At this purpose experiments on donkey milk casein dephosphorylation have been performed and the dephosphorylated casein fractions have been identified after 2-DE analysis followed by N-terminal sequencing. Among caseins were found mainly αs1- and β-caseins that showed a considerable heterogeneity due to variable degree of phosphorylation and to the presence of genetic variants. Finally, a quantitative determination of some antimicrobial proteins, such as lactoferrin and lactoperoxidase, that could be able to stimulate the development of the neonatal intestine, was performed in donkey milk, with the results being 0.080±0.0035 g/L and 0.11±0.027 mg/L, respectively. From the obtained data is evinced that human and donkey milk contain considerable amounts of lysozyme and lactoferrin but lactoperoxidase is present only in small amounts, confirming the high similarity between donkey and human milk. The present study on donkey milk proteins may be useful to assess the nutritional characteristics of this milk that is used to feed children affected by CMPA, but also may open the possibility of utilizing donkey milk in the general population to benefit subjects with CMPA, such as adults and the elderly.