Proteins hybrids

As noted previously, FeVaco can be extracted from AcF by the methods used to extract FeMoco from MoFe proteins (777). When FeVaco was combined with the polypeptides of the MoFe proteins from a nifB mutant, an active hybrid protein was created. However, although this protein had the H2 evolution and acetylene reduction... 

Fig. 24.8 Release of somatostatin from a hybrid protein by cyanogen bromide cleavage. Somatostatin can be purified free of cyanogen bromide and fragments of /J-galactosidase.

Jackson, B. L. and Groves, J. T. (2007) Hybrid protein-lipid patterns from aluminum templates. Langmuir, 23, 2052-2057. 

Figure 5.2. High-throughput mating assay for two-hybrid protein interaction screening. Yeast strains containing individual bait and prey clones are combined in a well and allowed to mate. Diploids are then selected and scored for a protein-protein interaction using the selection provided by the transcriptional reporter gene.

Sieber, V., Martinez, C.A. and Arnold, F.H. (2001) Libraries of hybrid proteins from distantly related sequences. Nature Biotechnology, 19, 456-460. 

Volume 326. Applications of Chimeric Genes and Hybrid Proteins (Part A Gene Expression and Protein Purification)... 

A set of articles devoted to hybrid protein-silica nanocomposites has been prepared for publication. 

Enbrel is a product now approved for medical use that is based upon this strategy. The product is an engineered hybrid protein consisting of the extracellular domain of the TNF p75 receptor fused directly to the Fc (constant) region of human IgG (see Box 13.2 for a discussion of antibody structure) The product is expressed in a CHO cell line from which it is excreted as a dimeric soluble protein of approximately 150 kDa. After purification and excipient addition (mannitol, sucrose and trometamol), the product is freeze-dried. It is indicated for the treatment of rheumatoid arthritis and is usually administered as a twice-weekly s.c. injection of 25 mg product reconstituted in WFI. Enbrel functions as a competitive inhibitor of TNF, a major pro-inflammatory cytokine. Binding of TNF to Enbrel prevents it from binding to its true cell surface receptors. The antibody Fc component of the hybrid protein confers an extended serum half-life on the product, increasing it by fivefold relative to the soluble TNF receptor portion alone. 

One of the major advantages of the strategy for the synthesis of hybrid proteins is the ability to... 

By combining bacterial expression and chemical synthesis Ras constructs with the properties of the post-translationally modified protein can be generated. These hybrid proteins can insert into artifical and biological membranes, have been proven to be efficient tools for biochemical, biophysical and biological experiments and can be synthesized in large amounts. Principally the same method is applicable to many of the Ras-related GTP-binding proteins or the y-subunit of heterotrimeric G proteins. 

Benz, R., Schmid, A., van der Ley, P. and Tommassen, J. (1989). Molecular basis of porin selectivity membrane experiments with OmpC-PhoE and OmpF-PhoE hybrid proteins of Escherichia coli K-12, Biochim. Biophys. Acta, 981, 8-14. 

Michiels, T., and Cornelis, G. (1991). Secretion of hybrid proteins by the Yersinia jop export system. J. Bacteriol. 173, 1677-1685. 

The construction of hybrid proteins containing bacterial CBDs may provide a cheap generic method for enzyme immobilization and/or purification using cellulosic matrices. The CBD can be fused at the amino or carboxyl terminus, as in the parent cellulase, to suit individual applications. We have constructed model fusion proteins using the C. fimi CBDs to demonstrate this potential. 

A second example of a toxin that has been used as targeting device is tetanus toxin. Tetanus toxin is a potent neurotoxin, which can undergo uptake in the nerve endings of motor neurones and subsequent retrograde transport into the central nervous system. The nontoxic C-fragment of tetanus toxin (TTC,451 amino acids), has been used to increase the neuronal uptake of the therapeutic protein SOD [57]. Following intravenous infusion, the recombinant hybrid protein reduced the occurrence of ischaemia-induced cerebral infarction in rats [58]. 

A. Azzi B. Chance (1969) Biochim. Biophys. Acta 189, 141. Selected entries from Methods in Enzymology [vol, page(s)] Calibration of calcium binding, 260, 425-427 luminescence measurement, 260, 424-425 mitochondria-targeted hybrid protein [calcium quantitation, 260, 418, 422, 424-428 stable expression, 260, 418-421 transient expression, 260, 420 intracellular localization, 260, 421-425 reconstitution with coelenterazine, 260, 422-422] structure, 260, 418. 

Bedouelle, H. and Duplay, P. (1988) Production in Escherichia coli and one-step purification of bifunctional hybrid proteins which bind maltose. Eur. J. Biochem., 171, 541-549. 

Fig. 14.4. Formation of a hybrid oncoprotein, illustrated by translocation of the Abl tyrosine kinase. The gene for the Ser-spedfic protein kinase BCR is fused with a part of the c-abl gene in the process of the Philadelphia chromosome translocation. Fusion genes are produced on chromosome 22, coding for various fusion proteins. The most important fusion proteins are the p -and p -BCR-Abl hybrid proteins, which have increased Tyr kinase activity and an altered subcel-lular location.

Pestka, S., The human interferon-alpha species and hybrid proteins. Semia Oncol, 1997. 24(3 Suppl 9) S9-4-S9-17. 

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