Mapping studies, peptides

Dhein S, Manicone N, Muller A, Gerwin R, Ziskoven U, Irankhahi A, Minke C, Klaus W A new synthetic antiarrhythmic peptide reduces dispersion of epicardial activation recovery interval and diminishes alterations of epicardial activation patterns induced by regional ischemia. A mapping study. Naunyn Schmiedebergs Arch Pharmacol 1994 350 174-184. 

To obtain optimum results in a FAB analysis samples should be relatively pure, though simple mixtures can be tolerated. We routinely perform mixture analysis with FAB, especially in our peptide mapping studies. However, certain shortcomings may arise. Complex mixtures are often plagued by a signal suppression effect where certain mixture components are preferentially ionized at the expense of others. When peptide digests are analyzed the hydrophobic components are ionized with much greater efficiency and the more hydrophilic components are suppressed. Surfactant type... 

Peptide mapping studies, generated by the cleavage of a protein into peptide fragments, must be highly reproducible and quantitative. Several electropherograms of protein digests have been obtained when chicken ovalbumin was cleaved by trypsin... 

Palkovits M (1984) Distribution of neuropeptides in the central nervous system a review of biochemical mapping studies. Prog Neurobiol 23 151-189 Palkovits M (2000) Stress-induced expression of co-loctilized neuropeptides in hypothalamic and amygdaloid neurons. Eur J Pharmacol 405 161-166 Palkovits M, Mezey E, Eskay RL (1987) Pro-opiomelanocortin-derived peptides (ACTH/beta-endorphin/ alpha-MSH) in brainstem btiroreceptor areas of the rat. Brain Res 436 323-338... 

For an experimental study of the S -subsite accessibility, S mapping studies (cf. Sect. 12.5.3.3.4) are suitable. By their specific S -binding capacity, peptide nucleophiles should be capable of pushing aside the acyl moiety from the S region more efficiently than water. Therefore, the aminolysis of acyl enzymes bearing the acyl moiety in S should proceed at higher rates compared with their hydrolysis. Indeed, from the mapping studies it follows that the p-values for the deacylation of Bz-D-Ala-trypsin are dramatically lower than for Bz-L-Ala-trypsin. Consequently, the experimental data of aminolysis also support this unique catalysis mechanism for substrate mimetics. 

In the present study, peptide mapping analysis was performed on PS II core complex to identify the iodinated residues on the D1 and D2. The iodination was also conducted on the PS II RC complex (Dl/D2/Cyt. b-559 complex), where Z and D are largely inactivated but P680 is active, in the presence of silicomolybdate (SiMo), to identify the subunits responsible for the binding of P680. 

As well as protein expression analysis, proteomics in its broadest sense also includes protein-protein interaction mapping. This can range from small studies using a single protein or peptide to fish ouf any proteins that interact with it... 

However, all of these studies were performed using model components in vitro—none have examined formaldehyde-induced modifications in vivo. Further, while modification sites have been mapped by MS/MS, intact cross-linked peptide species have not been observed in such experiments.49 This possibly indicates that the covalent bonds of the formaldehyde cross-links are not as strong as those of the peptide backbone. The resulting fragment ion spectra are similar to that of the unmodified peptide with the exception of 12Da or 30Da additions at modifications sites. Thirty Dalton modifications correspond to the addition of formaldehyde while 12 Da modifications indicate water elimination. 

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