Beta single chain

A. General description Interferon beta-la is produced by Chinese hamster ovary (CHO) cells into which the human interferon beta gene has been introduced. The amino-acid sequence of the recombinant protein produced by these cells is identical to naturally occurring interferon beta. Interferon beta-la is a single-chain glycosylated polypeptide, 166 amino-acid residues in length, with an approximate molecular weight of 22.5 kDa. 

Keywords Active imimnizadon Adenovims Adeno-associated vkus Alzheimer s disease Amyloid-beta Chemokine Cytokine Lendvirus Herpes simplex vims Isotypes Parkinson s disease Passive immunizadon Single-chain andbodies Thl cells Th2 cells Transgene Vector... 

Liu R, Yuan B, Emadi S, Zameer A, Schulz P, McAllister C, Lyub-chenko Y, Goud G, Sierks MR (2004) Single chain variable fragments against beta-amyloid (Abeta) can inhibit Abeta aggregation and prevent abeta-induced neurotoxicity. Biochemistry 43 6959-6967. 

The insulin molecule consists of 51 amino acids arranged in two chains, an A chain (21 amino acids) and B chain (30 amino acids), that are linked by two disulfide bonds. Proinsulin is the insulin precursor that is first processed in the Golgi apparatus of the beta cell where it is processed and packaged into granules. Proinsulin, a single-chain 86-amino acid peptide, is cleaved into insulin and C-peptide, a connecting peptide. These are secreted in equimolar portions... 

Galet C, Le Bourhis CM, Chopineau M, et al. Expression of a single beta-alpha chain protein of equine LH/CG in milk of transgenic rabbits and its biological activity. Mol. Cell. Endocrinol., 2001 174(1/2) 31-40. 

Insulin, Inutral Optisulin long. Polypeptide hormone produced in the beta cells of the islets of Laager-bans situated in the pancreas of all vertebrates. Synthesized in vivo via a single chain polypeptide precursor, proinsulin, native conformation has been established. Secreted directly into the bloodstream where it regulates carbohydrate metabolism, influences the synthesis of protein and of RNA, and the formation and storage of neutral lipids. The first protein for which chemical structure and precise mol wt were determined Sanger, Tuppy, Biochem. J. 49, 463, 481 (1951) ... 

Beta sheet. The beta sheet involves H-bonding between backbone residues in adjacent chains. In the beta sheet, a single chain forms H-bonds with its neighboring chains, with the donor (amide) and acceptor (carbonyl) atoms pointing sideways rather than along the chain, as in the alpha helix. Beta sheets can be either parallel, where the chains point in the same direction when represented in the amino- to carboxyl- terminus, or antiparallel, where the amino- to carboxyl- directions of the adjacent chains point in the same direction. (See Figure 5-5.)... 

The former arises from a beta-pinene chain or from a dipentene initiating mer unit. Single methyl arises from a beta-pinene initiating mer unit or a dipentene chain. Typically, the gem dimethyl/ single methyl ratio is 85/15 for a beta-pinene and 15/85 for a dipentene resin. 

Secondary structure refers to regularities or repeating features in the conformation of the protein chain s backbone. Four major types of secondary structure in proteins are (1) the alpha (a) helix, formed from a single strand of amino acids (2) the beta (P) sheet, formed from two or more amino acid strands (from either the same chain or from different chains) (3) the beta (P) bend or reverse turn, in a single strand and (4) the collagen helix, composed of three strands of amino acids. 

The P structure is one of the most important secondary structures in proteins. It occurs in about 80% of the soluble globular proteins whose structures have been determined. In many cases almost the entire protein is made up of P structure. Single strands of extended polypeptide chain are sometimes present within globular proteins but more often a chain folds back on itself to form a hairpin loop. A second fold may be added to form an antiparallel "P meander"102 and additional folds to form P sheets. Beta structures are found in silk fibers (Box 2-B) as well as in soluble proteins. 

Sequence analysis is a core area of bioinformatics research. There are four basic levels of biological structure (Table 1), termed primary, secondary, tertiary, and quaternary structure. Primary structure refers to the representation of a linear, hetero-polymeric macromolecule as a string of monomeric units. For example, the primary structure of DNA is represented as a string of nucleotides (G, C, A, T). Secondary structure refers to the local three-dimensional shape in subsections of macromolecules. For example, the alpha- and beta-sheets in protein structures are examples of secondary structure. Tertiary structure refers to the overall three-dimensional shape of a macromolecule, as in the crystal structure of an entire protein. Finally, quaternary structure represents macromolecule interactions, such as the way different peptide chains dimerize into a single functional protein. 

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