Biomaterial Database

Degradation of TN-C component of troponin by trypsin. 1977

W Drabikowski, and Z Grabarek, and B Barylko

The peptide pattern obtained during degradation of TN-C component of troponin by trypsin markedly depends on the concentration of calcium ions. In the presence of calcium higher than 0.1 mM a peptide with a mass of about 16 000 daltons is formed, followed by its splitting into two peptides (8500 and 7500 daltons), which accumulate during further digestion. When calcium is sequestred by EGTA the degradation of TN-C is much faster. The first products of digestion are the 11 000 and 7500 dalton peptides. The former one is degraded to 9700 dalton peptide and, subsequently, both peptides are split to small fragments. In the presence of calcium only three -NH2 groups per molecule of TN-C appear during digestion, whereas in its absence almost all peptide bonds available for trypsin are cleaved. The fragments of TN-C obtained in the presence of calcium are still able to interact with TN-I component as judged by disc-electrophoresis performed in the presence of calcium. During digestion in the presence of calcium only a slight decrease of tyrosyl intrinsic fluorescence occurs and the further decrease after removal of calcium bound to TN-C is fully reversible. Similarly, the content of alpha-helix decreases only slowly during digestion in the presence of calcium. All the results suggest that calcium stabilizes the structure of TN-C molecule, so that trypsin in the presence of calcium releases one small peptide from N-terminal not involved in the first "EF-hand" and the other from the region between pairs 1-2 and 3-4 of "EF-hands" in the nomenclature of Kretsinger (see Kretsinger and Barry [16]). The obtained fragments, containing almost exclusively pairs of "EF-hands", restore most of the properties of original TN-C molecule.

UI	MeSH Term	Description	Entries
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
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
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
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
D013050	Spectrometry, Fluorescence	Measurement of the intensity and quality of fluorescence.	Fluorescence Spectrophotometry,Fluorescence Spectroscopy,Spectrofluorometry,Fluorescence Spectrometry,Spectrophotometry, Fluorescence,Spectroscopy, Fluorescence
D014336	Troponin	One of the minor protein components of skeletal and cardiac muscles. It functions as the calcium-binding component in a complex with BETA-TROPOMYOSIN; ACTIN; and MYOSIN and confers calcium sensitivity to the cross-linked actin and myosin filaments. Troponin itself is a complex of three regulatory proteins (TROPONIN C; TROPONIN I; and TROPONIN T).	Troponin Complex,Troponins