Biomaterial Database

Purification and partial characterization of canine angiotensinogen. 1988

J A Oliver

Department of Medicine, Columbia University, College of Physicians and Surgeons, New York, New York 10032.

A procedure is described to isolate angiotensinogen (renin substrate) from canine plasma. The isolation procedure resulted in an 800-fold purification with a rate of recovery of approximately 12%. The purified protein has a specific activity of 24 micrograms of angiotensin I/mg protein. The amino terminal amino acid sequence of canine angiotensinogen was found to be identical to that of the horse but to differ from that of human and rat angiotensinogens. Canine angiotensinogen was heterogeneous with respect to molecular weight and isoelectric point. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of pure angiotensinogen revealed two closely spaced bands with apparent molecular weights of 58,000 and 56,000. Chromatofocusing showed four isoforms: Peaks of pure angiotensinogen eluted at pH levels of 4.32, 4.23, 4.15, and 4.04. Isoelectric focusing confirmed the presence of four isoforms. Thus, the purification procedure identified two molecular weight forms and four isoforms of canine angiotensinogen. Isolation of the four isoforms will allow their characterization and the study of their physiological significance.

UI	MeSH Term	Description	Entries
D007525	Isoelectric Focusing	Electrophoresis in which a pH gradient is established in a gel medium and proteins migrate until they reach the site (or focus) at which the pH is equal to their isoelectric point.	Electrofocusing,Focusing, Isoelectric
D008297	Male		Males
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004586	Electrophoresis	An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.	Electrophoreses
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
D000808	Angiotensinogen	An alpha-globulin of about 453 amino acids, depending on the species. It is produced by the liver in response to lowered blood pressure and secreted into blood circulation. Angiotensinogen is the inactive precursor of the ANGIOTENSINS produced in the body by successive enzyme cleavages. Cleavage of angiotensinogen by RENIN yields the decapeptide ANGIOTENSIN I. Further cleavage of angiotensin I (by ANGIOTENSIN CONVERTING ENZYME) yields the potent vasoconstrictor octapeptide ANGIOTENSIN II; and then, via other enzymes, other angiotensins also involved in the hemodynamic-regulating RENIN-ANGIOTENSIN SYSTEM.	Hypertensinogen,Renin-Substrate,SERPINA8,Proangiotensin,Renin Substrate Tetradecapeptide,Serpin A8,Renin Substrate,Tetradecapeptide, Renin Substrate
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