Biomaterial Database

Interaction of streptokinase with plasminogen. Isolation and characterization of a streptokinase degradation product. 1976

G E Siefring, and F J Castellino

When streptokinase is incubated with human or rabbit plasminogen, one event which occurs is a specific fragmentation of streptokinase. At least five major identifiable streptokinase fragments appear with time, and they possess molecular weights of approximately 40,000 (SK 1), 36,000 (SK 2), 31,000 (SK 3), 26,000 (SK 4), and 10,000 (SK 5) under denaturing conditions, as observed on calibrated sodium dodecyl sulfate-polyacrylamide gels, compared to native streptokinase of molecular weight 45,000. The amount of each of the fragments generated at given times of incubation of plasminogen and streptokinase depends upon the species of plasminogen employed. Utilizing rabbit plasminogen and streptokinase, the SK 4 fragment was purified. This fragment arises by proteolysis at both the NH2 and COOH regions of native streptokinase. However, when isolated utilizing dilute aqueous buffers, the SK 4 fragment contained a portion of the original NH2 terminus of native streptokinase noncovalently bound to the molecule (SK 4'). SK 4' is capable of activating human plasminogen to plasmin, albeit more slowly than native streptokinase. However, the SK 4'-human plasmin complex possess only very weak plasminogen-activating activity toward sheep plasminogen. Upon removal of the noncovalently bound small NH2-terminal peptide of native streptokinase from SK 4', SK 4 is formed. This particular fragment possesses practically no human plasminogen-activating activity and cannot be used as an activator of sheep plasminogen, even with added human plasminogen.

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
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010958	Plasminogen	Precursor of plasmin (FIBRINOLYSIN). It is a single-chain beta-globulin of molecular weight 80-90,000 found mostly in association with fibrinogen in plasma; plasminogen activators change it to fibrinolysin. It is used in wound debriding and has been investigated as a thrombolytic agent.	Profibrinolysin,Glu-Plasminogen,Glutamic Acid 1-Plasminogen,Glutamyl Plasminogen,1-Plasminogen, Glutamic Acid,Glu Plasminogen,Glutamic Acid 1 Plasminogen,Plasminogen, Glutamyl
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
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
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000596	Amino Acids	Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.	Amino Acid,Acid, Amino,Acids, Amino
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
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining