Postmortem titin proteolysis is influenced by sarcomere length in bovine muscle1
| Autor: | Kimberly Fisher, S. J. Wells, A. D. Weaver, David E. Gerrard, E. M. England, D. A. Mohrhauser |
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| Rok vydání: | 2012 |
| Předmět: |
Protease
biology medicine.diagnostic_test Chemistry medicine.medical_treatment Proteolysis Calpain General Medicine musculoskeletal system Sarcomere Tenderness Biochemistry Agarose gel electrophoresis Genetics biology.protein medicine Biophysics Animal Science and Zoology Titin medicine.symptom Myofibril Food Science |
| Zdroj: | Journal of Animal Science. 90:989-995 |
| ISSN: | 1525-3163 0021-8812 |
| DOI: | 10.2527/jas.2011-4278 |
| Popis: | The calpain protease system, in particular, μ-calpain is involved in the disassembly of specific myofibrillar proteins, resulting in tenderization of meat postmortem. Given the size, complexity, and integral nature of titin to the structure of the sarcomere, it is plausible that the length of a sarcomere may alter the susceptibility of various domains of titin to cleavage by the calpains. Therefore, we hypothesized titin degradation differs in a sarcomere-length-dependent manner in beef. After slaughter, beef carcasses were split and sides were either suspended by the Achilles tendon (normal suspension, NS) or by the aitchbone (hip suspension, HS). Immediately after suspension, samples were dissected from the LM, psoas major (PM), and semitendinosus (STN) muscles to serve as 0-d controls. After 24 h, 4 steaks were removed from each muscle and randomly assigned to 1-, 4-, 7-, or 10-d aging treatments. After the assigned aging period, myofibrils were purified for determination of sarcomere length. Warner-Bratzler shear force analysis was also performed to evaluate differences in tenderness. Muscle proteins were solubilized and subjected to SDS-VAGE (vertical agarose gel electrophoresis) to evaluate titin degradation. Sarcomere lengths differed (P 0.05) were detected in the disappearance of intact titin among suspension methods in the LM or STN. These data demonstrate that suspension method alters proteolysis of titin and suggest an increase in sarcomere length may contribute to the susceptibility of titin to postmortem proteolysis in beef. |
| Databáze: | OpenAIRE |
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