Encoding spectrometry

Significant additional interest in the potential role of oxytocin in labour developed from 1993, when it was reported for the first time that oxytocin, which had previously been thought to only be produced in the hypothalamus, may also be synthesised locally in the uterus as indicated by the presence of mRNA encoding for oxytocin [11]. This observation has recently been confirmed by using immunohistochemistry and mass spectrometry to confirm the presence of local oxytocin peptide in the uterus. These studies localised oxytocin to the chorionic trophoblast, decidual stroma and glandular epithelium, and demonstrated that local uterine concentrations of oxytocin increased with the onset of labour [12]. 

E. A. An affinity selection-mass spectrometry method for the identification of small molecule ligands from self-encoded combinatorial libraries, discovery of a novel antagonist of E. coli dihydrofolate reductase. Int. J. Mass. Spectrom. 2004, 238, 77-83. 

Very recently, we reported on a novel chemical encoding method that uses separate coding tags with a cleavable linker in the bead interior. These coding tags can be released for decoding with mass spectrometry.16... 

The structure of peptides containing 20 eukaryotic natural amino acids is now routinely determined by the use of automatic protein microsequencer, which uses Edman chemistry to convert each a-amino acid sequentially to its phenylthiohydantoin (PTH) derivative. The formed PTH-amino acids can be identified by their retention times on HPLC systems by comparison with reference standards derived from the 20 natural amino acids. For an OBOC peptide library composed of natural amino acids, the sequencing protocols of the automatic sequencer are well developed and standardized. However, structure determination of peptides composed of unnatural a-amino acids requires modification of the standard sequencing program.32 For peptides composed of non-a-amino acids, one can use an encoding strategy or mass spectrometry if a cleavable linker is employed. In this chapter, we shall focus on the new sequencing method we have developed for unnatural a-amino acids. 

Annis D.A., Athanasopoulos J., Curran P.J., Felsch J.S., Kalghatgi K., Lee W.H., Nash H.M., Orminati J.P.A., Rosner K.E., Shipps GW., Thaddupathy G.R.A., Tyler A.N., Vilenchik L., Wagner C.R., Wintner E.A., An affinity selection-mass spectrometry method for the identification of small molecule ligands from self-encoded combinatorial libraries. Discovery of a novel antagonist of E. coli dihydrofolate reductase Int. J. Mass Spectrom. 2004, 238, 77-83. 

Lane SJ, Pipe A, Unambiguous bead decoding by microelectrospray capillary electrochromatography tandem mass spectrometry of dansylated secondary amine tags from encoded combinatorial organic synthesis, Rapid Common. Mass Spectrom., 12 667-674, 1998. 

Y. H. Liu, G. Vellekamp, G. Chen, U. A. Mirza, D. WyUe, B. Twarowska, J. T. Tang, F. W. Porter, S. Wang, T. L. Nagabhushan, and B. N. Pramanik, Proteomic study of recombinant adenovirus 5 encoding hmnan p53 by matrix-assisted laser desorp-tion/ionization mass spectrometry in combination with database search, Int. J. Mass Spectrom. 226 (2003), 55-69. 

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