Proteomics Comparison of Longissimus Muscle between Hanwoo and Holstein Cattle

Abstract

This study was conducted to compare proteins expressed in M. longissimus from Hanwoo and Holstein steers immediatelyafter slaughter. Two-dimensional electrophoresis (2DE)/LC-MS/MS analysis revealed that the total number of detectableprotein spots from longissimus muscle tissues was slightly higher in Hanwoo (575 ± 65) than Holstein (534 ± 13) steers, butthat these numbers were not statistically significant due to large variation between replicates. A total of twelve protein spot sdid not match between sample groups, eight of which were expressed in the Hanwoo sample and four that were expressedin the Holstein sample. The protein spots detected in the Hanwoo sample included smooth muscle and non-muscle myosinalkali light chain 6B isomers, αB crystallin isomers, hemoglobin β-A chains, slow myosin heavy chains, and slow skeletalmuscle troponin T chains. Collectively, these proteins are a class of slow-twitch muscle fiber and mirror that Hanwoo mus-cle tissue sampled for the current study contained more slow-twitch muscle fibers than Holstein one. Conversely, proteinsdetected from the Holstein sample included ankyrin repeat domain 2 and creatin kinase isomers. Given that creatin kinaseisomers are related to the fast-twitch muscle, these results likely indicate that Holstein muscle tissue sampled for the curren tstudy contained more fast-twitch muscle fibers than Hanwoo beef.Key words: Hanwoo, Holstein, muscle proteome, meat quality, slow-twitch muscle