Phage technique

Gramatikoff K, Georgiev O, Schaffner W, Direct interaction rescue, a novel filamentous phage technique to study protein-protein interactions, Nucleic. Acids. Res., 22 5761-5762, 1994. 

These genetic experiments clearly demonstrated that the proposed structural model for the binding of these proteins to the phage operators was essentially correct. The second a helix in the helix-turn-helix motif is involved in recognizing operator sites as well as in the differential selection of operators by P22 Cro and repressor proteins. However, a note of caution is needed many other early models of DNA-protein interactions proved to be misleading, if not wrong. Modeling techniques are more sophisticated today but are still not infallible and are certainly not replacements for experimental determinations of structure. 

Another important advance has been the application of PyMS with ANNs to discriminate between methicillin-resistant and methicillin-sensitive Staphylococcus aureusIn this study DFA and HCA showed that the major source of variation between the pyrolysis mass spectra of 15 methicillin-resistant (MRSA) and 22 methicillin-sensitive Staphylococcus aureus (MSSA) strains resulted from the phage group of the bacteria, rather than from their resistance or sensitivity to methicillin. By contrast, ANNs could recognize those aspects of the pyrolysis mass spectra that differentiated MRSA and MSSA strains. These results gave the first demonstration that the combination of PyMS with ANNs could provide a rapid and accurate antibiotic-susceptibility testing technique. 

The use of phage-display techniques has identified peptide ligands with specific affinity to cell surface receptors or specific tissues (see Table 11.2). Such peptide homing devices can be... 

This question can be tackled with a concrete research project, which started recently in my group. The basic idea is to make a large number of NBPs 50 residues long. The maximum theoretical number of such chains is 20, and by using the well-known technique of phage display, gene libraries containing approximately 10 clones can be produced. 

In principle, it is not fair, or course, to approach a problem of prebiotic chemistry by using sophisticated techniques of present-day molecular biology, such as phage display. However in this case the particular research question was not the origin of life, but rather the question given a vast library of random polypeptide chains, what is the folding frequency The criterion utilized for determining whether a protein is folded or not was based on resistance to the hydrolytic power of proteases, with... 

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