In Situ Neutralization in Boc-chemistry Solid Phase Peptide Synthesis
| Autor: | Stephen B. H. Kent, Paul F. Alewood, Dianne Alewood, Martina Schnölzer, Alun Jones |
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| Rok vydání: | 2007 |
| Předmět: |
Time Factors
Formic Acid Esters Glutamine medicine.medical_treatment Bioengineering Peptide Biochemistry Chemical synthesis Mass Spectrometry Neutralization Analytical Chemistry chemistry.chemical_compound HIV Protease Drug Discovery Acyl Carrier Protein medicine Peptide synthesis Organic chemistry Racemization Chromatography High Pressure Liquid chemistry.chemical_classification Protease Chemistry Acetylation Stereoisomerism Native chemical ligation Chain termination Combinatorial chemistry Peptide Fragments Resins Synthetic Yield (chemistry) Reagent Polystyrenes Molecular Medicine Peptides |
| Zdroj: | International Journal of Peptide Research and Therapeutics. 13:31-44 |
| ISSN: | 1573-3904 1573-3149 |
| Popis: | Simple, effective protocols have been developed for manual and machine-assisted Boc-chemistry solid phase peptide synthesis on polystyrene resins. These use in situ neutralization [i.e. neutralization simultaneous with coupling], high concentrations (> 0.2 M) of Boc-amino acid-OBt esters plus base for rapid coupling, 100% TFA for rapid Boc group removal, and a single short (30 s) DMF flow wash between deprotection/coupling and between coupling/deprotection. Single 10 min coupling times were used throughout. Overall cycle times were 15 min for manual and 19 min for machine-assisted synthesis (75 residues per day). No racemization was detected in the base-catalyzed coupling step. Several side reactions were studied, and eliminated. These included: pyrrolidonecarboxylic acid formation from Gln in hot TFA-DMF; chain-termination by reaction with excess HBTU; and, chain termination by acetylation (from HOAc in commercial Boc-amino acids). The in situ neutralization protocols gave a significant increase in the efficiency of chain assembly, especially for “difficult” sequences arising from sequence-dependent peptide chain aggregation in standard (neutralization prior to coupling) Boc-chemistry SPPS protocols or in Fmoc-chemistry SPPS. Reported syntheses include HIV-1 protease(1–50,Cys.amide), HIV-1 protease(53–99), and the full length HIV-1 protease(1–99). |
| Databáze: | OpenAIRE |
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