Two-dimensional gel-based serum protein profile of growing piglets

In the present study we have introduced a proteomic workflow, 2-dimensional electrophoresis coupled with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) to create a 2-D map reflecting the characteristic pattern of serum proteins in growing piglets. Blood samples were collected from 6 piglets aged 50 days. Serum proteins were resolved at pH 3–10, followed by 12% SDS-PAGE. Reproducible protein spots (183) were picked from the gels and submitted for identification by peptide mass fingerprinting. As a result, 105 spots were positively identified, representing the products of 37 unique genes. Nearly half of the identified proteins (48.57%) were associated with transport and binding, 25.71% were classified as commonly circulating blood proteins, 11.43% as members of coagulation and complement factors, 8.57% as protease inhibitors, and 5.72% as proteases. We present 12 proteins that have not been previously identified in porcine serum/plasma samples using proteomic tools. Therefore, the gel-based map demonstrated in the current study complements currently available 2-D profiles of porcine plasma or serum and fills the gap between the existing protein patterns of neonatal and mature individuals. Moreover, the results of this work may be useful in monitoring changes in protein concentrations in young growing piglets in response to various physiological or pathological factors.