Peptides structural studies

The hugest and general problem of NMR spectroscopy is low sensitivity of measurements. This problem is, in particular, painfifl when rare spins are under investigation. To this group belong both, most important firom peptide structural studies point of view nuclei, and The natural... 

Structure of GFP and its chromophore. To study the chro-mophore of GFP, a sample of GFP was denatured by heating it at 90°C. It was digested with papain, and then a peptide containing the fluorophore was isolated and purified from the digested mixture. The structural study of the peptide has indicated that the chromophore of GFP is an imidazolone derivative shown below (Shimomura, 1979). This chromophore structure was confirmed later by Cody etal. (1993) in a hexapeptide isolated from GFP. It is intriguing that the structure of the GFP chromophore is a part of the structure of coelenterazine. 

For the synthesis and structural studies of /9-peptides, Seebach and coworkers have prepared acycHc /9-amino acids with different substitution pattern (including /9A, y 3,3, 3,3 -amino acids) and with the side chains of natural... 

Garcia, K. C. and Teyton, L. (1998), T-cell receptor peptide-MHC interactions biological lessons from structural studies , Curr. Opinion Biotechnol., 4, 338-343. 

Schafer, L., C. Van Alsenoy, and J. N. Scarsdale. 1982. Ab Initio Studies of Structural Features Not Easily Amenable to Experiment. 23. Molecular Structures and Conformational Analysis of the Dipeptide N-acetyl-N -methyl Glycyl Amide and the Significance of Local Geometries for Peptide Structures. J. Chem. Phys. 76, 1439-1444. 

Here, we discuss a solid-state 19F-NMR approach that has been developed for structural studies of MAPs in lipid bilayers, and how this can be translated to measurements in native biomembranes. We review the essentials of the methodology and discuss key objectives in the practice of 19F-labelling of peptides. Furthermore, the preparation of macroscopically oriented biomembranes on solid supports is discussed in the context of other membrane models. Two native biomembrane systems are presented as examples human erythrocyte ghosts as representatives of eukaryotic cell membranes, and protoplasts from Micrococcus luteus as membranes... 

Kubyshkin VS, Komarov IV, Afonin S, Mykhailiuk PK, Grage SL, Ulrich AS (2011) Trifluoromethyl-substituted a-amino acids as solid state 19F-NMR labels for structural studies of membrane-bound peptides. In Gouvemeur V, Miiller K (eds) Fluorine in pharmaceutical and medicinal chemistry from biophysical aspects to clinical applications. Imperial College Press (in press)... 

Afonin S (2004) Structural studies on membrane-active peptides in lipid bilayers by solid state 19F-NMR. PhD thesis, University of Jena... 

Fraga, S. and Thornton, S. E. Theoretical studies of peptidic structures. Environmental effects, Theor. 

To summarize, the picture that has emerged from these various studies of peptide structure-activity is as follows ... 

I Abdelmoty, F Albericio, LA Carpino, BM Foxman, SA Kates. Structural studies of reagents for peptide bond formation crystal and molecular structures of HBTU and HATU. Lett Pept Sci 1, 57, 1994. 

NMR is a remarkably flexible technique that can be effectively used to address many analytical issues in the development of biopharmaceutical products. Although it is already more than 50 years old, NMR is still underutilized in the biopharmaceutical industry for solving process-related analytical problems. In this chapter, we have described many simple and useful NMR applications for biopharmaceutical process development and validation. In particular, quantitative NMR analysis is perhaps the most important application. It is suitable for quantitating small organic molecules with a detection limit of 1 to 10 p.g/ml. In general, only simple one-dimensional NMR experiments are required for quantitative analysis. The other important application of NMR in biopharmaceutical development is the structural characterization of molecules that are product related (e.g., carbohydrates and peptide fragments) or process related (e.g., impurities and buffer components). However, structural studies typically require sophisticated multidimensional NMR experiments. 

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