Biomaterial Database

Relationship between proteolysis and water-holding of myofibrils. 2017

Zhen Zeng, and Cheng Li, and Per Ertbjerg

College of Food Science, Sichuan Agricultural University, 625014 Yaan, China; Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.

The purpose of this study was to increase the knowledge on the relationship between proteolysis of myofibrillar proteins and the water-holding of meat. Myofibrils isolated from porcine longissimus thoracis et lumborum muscle were used as a model system. Myofibrils were incubated with either calpain-2, the proteasome or a lysosomal extract at 25°C for 2h. All three proteolytic systems improved the relative water-holding and generally there was a larger effect with increasing amount of enzymes in the incubation. The improved water-holding occurred in parallel to degradation of myofibrillar proteins. Desmin was degraded by calpain-2 as well as by lysosomal enzymes and α-actinin was released by the proteasome. We here propose a model in which degradation of proteins in and around the Z-disk allows overall swelling of the filament lattice and more specifically in the I-band area. In conclusion, proteolytic degradation of myofibrillar proteins by calpain-2, the proteasome or lysosomal enzymes improves the water-holding of myofibrils.

UI	MeSH Term	Description	Entries
D008247	Lysosomes	A class of morphologically heterogeneous cytoplasmic particles in animal and plant tissues characterized by their content of hydrolytic enzymes and the structure-linked latency of these enzymes. The intracellular functions of lysosomes depend on their lytic potential. The single unit membrane of the lysosome acts as a barrier between the enzymes enclosed in the lysosome and the external substrate. The activity of the enzymes contained in lysosomes is limited or nil unless the vesicle in which they are enclosed is ruptured or undergoes MEMBRANE FUSION. (From Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed).	Autolysosome,Autolysosomes,Lysosome
D009124	Muscle Proteins	The protein constituents of muscle, the major ones being ACTINS and MYOSINS. More than a dozen accessory proteins exist including TROPONIN; TROPOMYOSIN; and DYSTROPHIN.	Muscle Protein,Protein, Muscle,Proteins, Muscle
D009210	Myofibrils	The long cylindrical contractile organelles of STRIATED MUSCLE cells composed of ACTIN FILAMENTS; MYOSIN filaments; and other proteins organized in arrays of repeating units called SARCOMERES .	Myofilaments,Myofibril,Myofilament
D002154	Calpain	Cysteine proteinase found in many tissues. Hydrolyzes a variety of endogenous proteins including NEUROPEPTIDES; CYTOSKELETAL PROTEINS; proteins from SMOOTH MUSCLE; CARDIAC MUSCLE; liver; platelets; and erythrocytes. Two subclasses having high and low calcium sensitivity are known. Removes Z-discs and M-lines from myofibrils. Activates phosphorylase kinase and cyclic nucleotide-independent protein kinase. This enzyme was formerly listed as EC 3.4.22.4.	Calcium-Activated Neutral Protease,Calcium-Dependent Neutral Proteinase,Ca2+-Activated Protease,Calcium-Activated Neutral Proteinase,Calcium-Activated Protease,Calcium-Dependent Neutral Protease,Calpain I,Calpain II,Desminase,Ca2+ Activated Protease,Calcium Activated Neutral Protease,Calcium Activated Neutral Proteinase,Calcium Activated Protease,Calcium Dependent Neutral Protease,Calcium Dependent Neutral Proteinase,Neutral Protease, Calcium-Activated,Neutral Protease, Calcium-Dependent,Neutral Proteinase, Calcium-Activated,Neutral Proteinase, Calcium-Dependent,Protease, Ca2+-Activated,Protease, Calcium-Activated,Protease, Calcium-Activated Neutral,Protease, Calcium-Dependent Neutral,Proteinase, Calcium-Activated Neutral,Proteinase, Calcium-Dependent Neutral
D003893	Desmin	An intermediate filament protein found predominantly in smooth, skeletal, and cardiac muscle cells. Localized at the Z line. MW 50,000 to 55,000 is species dependent.	Skeletin
D000069466	Red Meat	Meat such as beef, goat, pork, or lamb which contains more MYOGLOBIN than POULTRY or SEAFOOD.	Lamb Meat,Veal,Beef,Lamb Meats,Meat, Lamb,Meat, Red,Meats, Lamb,Meats, Red,Red Meats
D000185	Actinin	A protein factor that regulates the length of R-actin. It is chemically similar, but immunochemically distinguishable from actin.	alpha-Actinin,Eu-Actinin,beta-Actinin,Eu Actinin,alpha Actinin,beta Actinin
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014867	Water	A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Hydrogen Oxide
D046988	Proteasome Endopeptidase Complex	A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.	20S Proteasome,Ingensin,Macropain,Macroxyproteinase,Multicatalytic Endopeptidase Complex,Multicatalytic Proteinase,Prosome,Proteasome,Complex, Multicatalytic Endopeptidase,Complex, Proteasome Endopeptidase,Endopeptidase Complex, Multicatalytic,Endopeptidase Complex, Proteasome,Proteasome, 20S,Proteinase, Multicatalytic