Disulfide-containing peptides

Disulfide-containing peptides still present a difficulty, in that there is the potential for the catalytic desulfuration of the disulfide bridge during the dehalogenation of the Phe(3,5-I2,4-NH2) residue 93 Replacement of the disulfide bridge by a hydrocarbon bridge, when tolerated, represents a plausible solution 31 ... 

A disulfide-containing polypeptide chain needs to be cleaved into smaller fragments prior to mass spectrometry analysis. The cleavage of a protein generates two types of disulfide-containing peptides, intrachain (a or intramolecular) and interchain (b or intermolecular) ... 

Reduction of Disulfide Bonds The disulfide-bridged peptides can also be identified by analyzing the protein digest before and after the dithiothreitol reduction of disulfide bonds. The peaks due to disulfide-containing peptides will disappear, and new peaks related to reduced peptides will appear. If the peptide... 

On-Probe Oxidation In this procedure, thiol- and disulfide-containing peptides are treated with performic acid on the FAB probe to convert each cysteine residue to cysteic acid a concomitant increase of 98 Da in the mass of a peptide that contains an intramolecular disulfide bond results [9] ... 

Identification of Disulfide-Containing Peptides by Electron-Capture Dissociation... 

It is also feasible to employ BCD to identify disulfide-containing peptides, but it requires FT-ICR-MS instrumentation. BCD of the BSI-produced multiply charged ions of proteins and peptides leads to cleavage of the disulfide bond to provide important sequence information [12]. The capture of an electron by a multiply charged protein ion releases an H atom, which is captured by the disulfide bond to cause its dissociation ... 

Y.P. Sun, D.L. Smith and R.E. Shoup, Simultaneous detection of thiol-containing and disulfide-containing peptides by electrochemical high-performance liquid-chromatography with identification by mass-spectrometry. Anal. Biochem., 1991, 197, 69-76. 

C.T. Garvie, K.M. Straub and R.K. Lynn, Quantitative liquid chromatographic determination of disulfide-containing peptide analogues of vasopressin with dual Hg/Au electrochemical detection, J. Chromatogr., 1987, 413, 43-52. 

SST is a family of 14-amino acid (SST-14) and 28-amino acid (SST-28) cyclic disulfide-containing peptides. SST is widely distributed in the human body, in particular in the central and peripheral nervous system, endocrine glands, immune, system, and gastrointestinal tract, where it acts as neurotransmitter, neurohormone, or local hormone. Moreover, SST and SST analogs have been shown to inhibit mmor growth in many animal mmor models (116-118). 

Intrigued by the question of the functional equivalence or non-equivalence of the individual sulfur atoms in disulfide-containing peptides and proteins in general, we were tempted to interpret the non-equivalence of both selenium centers in terms of a non-equivalence of both sulfur centers in the hormone analogs. 

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