title: Bovine muscle 20S proteasome. II: Contribution of the 20S proteasome to meat tenderization as revealed by an ultrastructural approach.
abstract: The role of the 20S proteasome proteolytic effects was revisited using an ultrastructural approach with the aim to explain some particular structural changes identified in type I muscles and in high pH meat. In both types of meat, major changes observed after ageing are an increase in the thickness of the Z-line followed by the appearance of an amorphous protein structure spreading out over the I-band. This was followed by a total degradation of this amorphous structure and of the Z-line. Partial transversal fragmentation of the myofibrils within the I-band can also be detected. The data reported clearly demonstrate that the 20S proteasome was able to mimic these sequential structural changes, a feature never obtained with either calpains or cathepsins. It is the first time that a direct implication of this complex in postmortem muscle is postulated.
authors: Meat Research Station, INRA-Theix, 63122 Saint Genès Champanelle, France.
authors: D
authors: D
authors: Dutaud
authors: L
authors: L
authors: Aubry
authors: F
authors: F
authors: Guignot
authors: X
authors: X
authors: Vignon
authors: G
authors: G
authors: Monin
authors: A
authors: A
authors: Ouali