ABSTRACT
Synthetic peptides are being utilized increasingly in biochemical, molecular biological, and pharmacological research in addition to finding exciting new uses in drug discovery programs. Thus, sample purity and sequence integrity are both extremely important. The use of impure or incorrectly synthesized peptides can result in significant losses of time and resources. The Peptide Synthesis Research Group (PSRG) of the Association of Biomolecular Resource Facilities (ABRF) recommends that along with stringent quality control measures that are carried out during synthesis, each product should be characterized by independent biophysical methods, including, as a minimum,
reversed-phase high-performance liquid chromatography (RP-HPLC) and mass spectrometry (MS) [electrospray ionization (ESI-MS) or matrix-assisted laser desorption-ionization (MALDI-MS)]. Furthermore, for accurate quantification of synthetic peptides, amino acid analysis (AAA) is the optimal method. Then, if discrepancies in a peptide sample are indicated by the analytical data, either repurification or resynthesis can be undertaken. Problems with a sequence can often be readily deduced by either Edman degradation analysis or tandem mass spectrometry. Capillary electrophoresis (CE) is also a powerful tool for further evaluating problematic peptides. In the sections that follow are descriptions of a number of the methods that are highly effective for evaluation of synthetic peptides, along with examples of their application for specific problems. The methods covered include analytical HPLC, CE, MS, AAA, and Edman degradation sequence analysis.
