Optimization of the synthesis of peptide combinatorial libraries using a one-pot method

Summary Conditions for the synthesis of synthetic peptide combinatorial libraries (SPCLs) from mixtures of amino acids were explored. In a one-pot synthesis, the effect of the starting concentrations of amino acids on the resulting library composition was studied, and the optimum balance of amino acids was determined. Protein sequencing, MALDI-TOF, and amino acid analysis were used for the evaluation of the libraries, and their relative merits are discussed. The effects of continuous-flow automated synthesis instrumentation in conjunction with polyethylene glycol-polystyrene (PEG-PS) graft supports and various cleavage cocktails on the successful synthesis of SPCLs were examined.Abbreviations AA amino acid - Boc tert-butyloxycarbonyl - tBu tert-butyl - Bzl benzyl - DIEA N,N-diisopropylethylamine - DMF N,N-dimethylformamide - ESI-MS electrospray ionization mass spectrometry - Fmoc 9-fluorenylmethyloxycarbonyl - HATU N-[(dimethylamino)-1H-1,2,3triazolo[4,5-b]pyridin-1-ylmethylene]-N-methylmethanamimum hexafluorophosphateN-oxide - HOAt 1-hydroxy-7-azabenzotriazole - HPLC highperformance liquid chromatography - MALDI-TOF matrix-assisted laser desorption ionization/time of flight - MBHA methylbenzhydrylamine - PAL 5-(4-(9-fluorenylmethyloxycarbonyl)aminomethyl-3,5-dimethoxyphenoxy)valeric acid handle - PEG-PS polyethylene glycol-polystyrene graft supports - Pbf 2,2,4,6,7-pentamethylfuran-5-sulphonyl - PNA peptide nucleic acid - PTH phenylthiohydantion - PS polystyrene - Reagent R TFA-thioanisole-1,2-ethanedithiol-anisole (90:5:3:2) - SPCL synthetic peptide combinatorial library - Trt triphenylmethyl - TFA trifluoroacetic acidAmino acids and peptides are abbreviated and designated following the rules of the IUPAC-IUB Commission of Biochemical Nomenclature [J. Biol. Chem., 247 (1972) 977–983]. Amino acid symbols denote thel-configuration unless indicated otherwise.Parts of this paper were presented at the 4th International Symposium on Solid Phase Synthesis and Combinatorial Chemical Libraries, Edinburgh, Scotland, U.K., September 12–16, 1995.