Abstract:

The objective of this work was to establish the optimal two-dimensional electrophoresis (2DE) protocol for
proteomic study of yak longissimus dorsi muscle. The extraction efficiencies of four protein extraction methods, including
high-speed centrifugation, trichloroacetic acid-acetone extraction, Tris-phenol extraction, and double lysis, were evaluated.
After 2DE, the gels were stained with silver, and the spots were analyzed by image Master 2D platinum software and 6
protein spots were identified by MALDI-TOF-TOF/MS. The results showed that the optimal protein extraction method
for yak muscle was high-speed centrifugation method due to the highest protein concentration and the largest number of
detectable protein spots, as well as its relatively short analytic time and operation convenience. The randomly selected 6
protein spots were identified as 5 different proteins, i.e., myosin regulatory light chain 2, fatty acid binding protein, malate
dehydrogenase, phosphoglucomutase-1, and peroxiredoxin-1. The 2DE system developed in the current study is suitable for
further proteomic analysis of yak muscle.

Key words: yak, two-dimensional electrophoresis, protein extraction, mass spectrometry