Biomaterial Database

The structure of rat proalbumin. 1975

J H Russell, and D M Geller

The structure of rat proalbumin, a liver precursor to rat serum albumin, has been determined to consist of the hexapeptide Arg-Gly-Val-Phe-Arg-Arg attached to the NH2 terminus of the polypeptide chain of rat serum albumin. Edman degradation of a proalbumin preparation for 14 rounds gave the major sequence Arg-Gly-Val-Phe-Arg-Arg-Glu-Ala-His-Lys-Ser-Glu-Ile-Ala. A comparison of cyanogen bromide fragments suggests that these two proteins differ only in this respect. On treatment with cyanogen bromide, these proteins gave three classes of peptides with molecular weights of 30,000, 10,000, and smaller than or equal to 5,000. A combination of gel filtration, electrofocusing, and ion exchange established that these peptides were indistinguishable, with exception of those of 10,000 molecular weight. By amino acid and sequence analyses this fraction from rat serum albumin was found to be the NH2-terminal fragment. Radiochemical amino acid and sequence analyses show that the NH2-terminal hexapeptide is the major fragment released from proalbumin by limited tryptic hydrolysis. The protein that remains cannot be distinguished from rat serum albumin.

UI	MeSH Term	Description	Entries
D008861	Microsomes	Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Microsome
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009842	Oligopeptides	Peptides composed of between two and twelve amino acids.	Oligopeptide
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
D011228	Prealbumin	A tetrameric protein, molecular weight between 50,000 and 70,000, consisting of 4 equal chains, and migrating on electrophoresis in 3 fractions more mobile than serum albumin. Its concentration ranges from 7 to 33 per cent in the serum, but levels decrease in liver disease.	Proalbumin,Transthyretin
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
D003488	Cyanogen Bromide	Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.	Bromide, Cyanogen
D005260	Female		Females
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