title: Serine Protease Inhibitors as Good Predictors of Meat Tenderness: Which Are They and What Are Their Functions?
abstract: Since years, serine proteases and their inhibitors were an enigma to meat scientists. They were indeed considered to be extracellular and to play no role in postmortem muscle proteolysis. In the 1990's, we observed that protease inhibitors levels in muscles are a better predictor of meat tenderness than their target enzymes. From a practical point of view, we therefore choose to look for serine protease inhibitors rather than their target enzymes, i.e. serine proteases and the purpose of this report was to overview the findings obtained. Fractionation of a muscle crude extract by gel filtration revealed three major trypsin inhibitory fractions designed as F1 (Mr:50-70 kDa), F2 (Mr:40-60 kDa) and F3 (Mr:10-15kD) which were analyzed separately. Besides antithrombin III, an heparin dependent thrombin inhibitor, F1 and F2 comprised a large set of closely related trypsin inhibitors encoded by at least 8 genes bovSERPINA3-1 to A3-8 and able to inhibit also strongly initiator and effector caspases. They all belong to the serpin superfamily, known to form covalent complexes with their target enzymes, were located within muscle cells and found in all tissues and fluids examined irrespective of the animal species. Potential biological functions in living and postmortem muscle were proposed for all of them. In contrast to F1 and F2 which have been more extensively investigated only preliminary findings were provided for F3. Taken together, these results tend to ascertain the onset of apoptosis in postmortem muscle. However, the exact mechanisms driving the cell towards apoptosis and how apoptosis, an energy dependent process, can be completed postmortem remain still unclear.
authors.affiliation: a Equipe Maquav, INATAA, Université Frères Mentouri , Constantine , Algeria.
authors.forename: Yasmine
authors.initials: Y
authors.lastname: Boudida
authors.affiliation: a Equipe Maquav, INATAA, Université Frères Mentouri , Constantine , Algeria.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Gagaoua
authors.affiliation: a Equipe Maquav, INATAA, Université Frères Mentouri , Constantine , Algeria.
authors.forename: Samira
authors.initials: S
authors.lastname: Becila
authors.affiliation: b UMR1213 Herbivores, URH - AMUVI, INRA de Clermont Ferrand Theix, St Genès Champanelle , France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Picard
authors.affiliation: a Equipe Maquav, INATAA, Université Frères Mentouri , Constantine , Algeria.
authors.forename: Abdelghani
authors.initials: A
authors.lastname: Boudjellal
authors.affiliation: c Agroindustrial Engineering Department, Universidad De Guanajuato, Salvatierra , Guanajuato , Mexico.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Herrera-Mendez
authors.affiliation: d Instituto de Agroquímica y Tecnología de Alimentos, CSIC , Burjassot (Valencia ), Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Sentandreu
authors.affiliation: e UR370, QuaPA, INRA de Clermont Ferrand - Theix, St Genès Champanelle , France.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ouali
mesh_terms: D000818:Animals; D063427:Food Quality; D008460:Meat / Q000592:standards*; D008958:Models, Molecular; D018482:Muscle, Skeletal / Q000201:enzymology; D011487:Protein Conformation; D015842:Serine Proteinase Inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D015842:Serine Proteinase Inhibitors
keywords: Serine protease inhibitors; apoptosis; bovine muscle; caspases; cell differentiation; serpins