title: Difference in postmortem degradation pattern among troponin T isoforms expressed in bovine longissimus, diaphragm, and masseter muscles.
abstract: The postmortem degradation of troponin T (TnT) in bovine longissimus (LT), diaphragm (DP), and masseter (MS) was analyzed. A 28.3kDa (conventional 30kDa) fragment of fast-type TnT isoforms showed the highest content in both LT and DP, where a 35.4kDa isoform had the highest expression among the other fast isoforms. Meanwhile, a 26.0kDa fragment was found to be the most highly produced among the fast TnT fragments in MS, where the expression of 36.5 and 32.8kDa isoforms was higher than that of 35.4 and 34.8kDa isoforms. Thus, the compositions of both the intact TnT isoform proteins and the postmortem fragments differed among the muscles examined, indicating that each TnT isoform degrades into a specific fragment in each muscle. Among the muscles, the LT muscle showed a high extent of TnT degradation and the highest expression of fast TnT isoforms containing a taste-related peptide sequence.
authors: Department of Animal Products, National Institute of Livestock and Grassland Science, Tsukuba, Ibaraki 305-0901, Japan.
authors: Susumu
authors: S
authors: Muroya
authors: Ikuyo
authors: I
authors: Nakajima
authors: Mika
authors: M
authors: Oe
authors: Koichi
authors: K
authors: Chikuni