Please use this identifier to cite or link to this item: https://repositorio.unifesp.br/handle/11600/26596
Title: Fmoc-POAC: [(9-fluorenylmethyloxycarbonyl)-2,2,5,5-tetramethylpyrrolidine-N-oxyl-3-amino-4-carboxylic acid]: A novel protected spin labeled beta-amino acid for peptide and protein chemistry
Authors: Tominaga, Mineko [UNIFESP]
Barbosa, Simone Reis [UNIFESP]
Poletti, Erick Fernando [UNIFESP]
Zukerman-Schpector, Julio
Marchetto, Reinaldo
Schreier, Shirley
Paiva, Antonio Cechelli de Mattos [UNIFESP]
Nakaie, Clovis Ryuichi [UNIFESP]
Universidade Federal de São Paulo (UNIFESP)
Universidade Federal de São Carlos (UFSCar)
UNESP
Universidade de São Paulo (USP)
Keywords: peptide
spin label
electron paramagnetic resonance
amino acid
TOAC
POAC
Issue Date: 1-Aug-2001
Publisher: Pharmaceutical Soc Japan
Citation: Chemical & Pharmaceutical Bulletin. Tokyo: Pharmaceutical Soc Japan, v. 49, n. 8, p. 1027-1029, 2001.
Abstract: The stable free radical 2,2,6,6-tetramethylpiperidine-N-oxyl-4-amino-4-carboxylic acid (TOAC) is the only spin labeled amino acid that has been used to date to successfully label peptide sequences for structural studies. However, severe difficulty in coupling the subsequent amino acid has been the most serious shortcoming of this paramagnetic marker. This problem stems from the low nucleophilicity of TOAC's amine group towards the acylation reaction during peptide chain elongation. the present report introduces the alternative beta -amino acid 2,2,5,5-tetramethylpyrrolidine-N-oxyl-3-amino-4-carboxylic acid (POAC), potentially useful in peptide and protein chemistry. Investigations aimed at addressing the stereochemistry of this cyclic molecule through X-ray diffraction measurements of crystalline and bulk samples revealed that it consists only of the trans conformer. the 9-fluorenylmethyloxyearbonyl group (Fmoc) was chosen for temporary protection of the POAC amine function, allowing insertion of the probe at any position in a peptide sequence. the vasoactive octapeptide angiotensin II (AII, DRVYIHPF) was synthesized by replacing Pro(7) with POAC. the reaction of Fmoc-POAC with the peptidyl-resin occurred smoothly, and the coupling of the subsequent amino acid showed a much faster reaction when compared with TOAC. POAC(7)-AII was obtained in good yield, demonstrating that, in addition to TOAC, POAC is a convenient amino acid for the synthesis of spin labeled peptide analogues. the present findings open the possibility of a wide range of chemical and biological applications for this novel beta -amino acid derivative, including structural investigations involving its differentiated bend-inducing characteristics.
URI: http://repositorio.unifesp.br/handle/11600/26596
ISSN: 0009-2363
Other Identifiers: http://dx.doi.org/10.1248/cpb.49.1027
Appears in Collections:Em verificação - Geral

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