Myoglobin peptide sequences

Mass spectrometry (electron impact, field desorption, and chemical ionization ) in principal provides either a completely different, alternative method for peptide sequencing or a valuable supplement to the standard method. Applications have, however, been relatively few so far. Further studies on the mass spectral patterns obtained from model compounds have been reported. These should allow inter alia distinctions to be made between a- and y-glutamyl peptides and between leucyl and isoleucyl residues. Sequence studies on myoglobin from the bottle-nosed dolphin were facilitated by a computer comparison method. In this method, a peptide was either deuteroacetylated and deuteropermethylated or subjected to one step of the Edman degradation, followed by deuteroacetylation and deuteropermethylation. Comparison of the mass spectra of these derivatives aided the analysis.""... 

Iwai, K., Fukuoka, S.-I., Fushiki, T., Kido, K., Sengoku, Y., and Semba, T. (1988) Preparation of a verifiable peptide-protein immunogen direction-controlled conjugation of a synthetic fragment of the monitor peptide with myoglobin and application for sequence analysis. Anal. Biochem. 171, 277-282. 

A miniaturized protein and peptide microsequencer consisting of either a fused silica capillary reactor or a microreactor made of Teflon is described. The performance of the miniaturized sequencer was evaluated by sequencing 33 and 27 picomoles of myoglobin that were covalently attached to Sequelon-DITC. The products generated by the sequencer were analyzed using capillary electrophoresis with thermo-optical absorbance detection. This CE system provides reproducible migration time (< 0.4% of RSD) and detection limits of less than 4 fmol. 

Proteins like insulin, myoglobin and lysozyme were also loaded onto the non-coated CE capillary and collected for nES/MS analysis and Edman sequencing. Because the peak width of proteins is larger than that of the peptides on the non-coated column, the window is relatively wide (about 10 minutes) under 7.5 kV for fraction collection. Figure 8a is the nES/MS spectrum of... 

Secondary structure must not be confused with the overall shape of a polypeptide. The overall shape of a polypeptide arises from the different regions of secondary structure folding upon each other and is called the tertiary structure if it involves only the same peptide or the quaternary structure if it involves two or more separate peptides. For example, the complete structure of myoglobin in Figure 6.1 arises from primary structure (the sequence of amino acids shown as numbers), the secondary structure (the 3D scheme by which the individual amino acids are arranged with respect to each other), and the tertiary structure (the way in which the secondary structures are folded together to make the globular molecule). 

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