As one of the world’s most trusted suppliers of custom peptides, AnaSpec has a well-earned reputation for expertise in the field of peptide chemistry.  We are pleased to introduce two novel amino acids that offer additional tools and functionality for peptide chemists like ourselves. 

Fmoc-TOAC-OH
                               

TOAC (2,2,6,6-tetramethylpiperidine-1oxyl-4-amino-4-carboxylic acid) is a nitroxide spin-label used in electron spin resonance, ESR (also known as electron paramagnetic resonance, EPR) studies.^1,2 This C^a-tetrasubstituted cyclic structure unnatural amino acid is an excellent and relatively rigid ESR probe, making it a useful tool in the study of peptide backbone conformational properties.²  TOAC has been shown to be an effective ß-turn and 3₁₀/a-helix promoter in peptides as well as a fluorescence quencher. Publications have reported the use of Fmoc-TOAC-OH in the synthesis of internally containing spin probe peptide sequence,^3,4 which was previously not possible with BOC protected TOAC.   The incorporation of this amino acid has also been reported in the synthesis of a biologically active hormone.² 

 
Fmoc-Lys(Nvoc)-OH
                                     

4, 5-dimethoxy-2-nitrobenzyloxycarbonyl (Nvoc) is a photocleavable protecting group used for side-chain amine protection or for a-amine blocking. Compared with another photocleavable protecting group Z(2-NO₂), Nvoc deprotection gave a higher yield under similar condition. Fmoc-Lys(Nvoc)-OH has been used in the solid phase peptide synthesis of selectively functionalized HIV and caged peptides.^5,6 The removal of the Nvoc group, from the protected peptide, is compatible with the presence of a reactive maleimide linker which is useful for conjugation of peptides to proteins containing thiol groups.⁵

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Product	Size	Catalog #
Fmoc - TOAC - OH  NEW	5 mg	62658
"Fmoc-Lys(4,5-dimethoxy-2-nitro-benzyloxycarbonyl)-OH" NEW Fmoc-Lys(Nvoc)-OH	1 g	62574-1000
"Fmoc-Lys(4,5-dimethoxy-2-nitro-benzyloxycarbonyl)-OH" NEW Fmoc-Lys(Nvoc)-OH	0.5 g	62574-500

Heavy Isotope Labeled Resins and Amino Acids:

Product	Size	Catalog #
Fmoc-Lys(Boc)-HMP Resin, U-13C6, U-15N2 Labeled NEW	0.1 g	62659
Fmoc-Arg(Pbf)-HMP Resin, U-13C6, U-15N4 Labeled NEW	0.1 g	62660
Fmoc - Lys(Boc) - OH (1 – 13C)  NEW	0.1 g 0.25 g	61562-01 61562-025
Fmoc - Lys(Boc) - OH (Alpha - 15N)  NEW	0.1 g 0.25 g	61560-01 61560-025

Related Services:

Custom Peptide Synthesis with Unusual Amino Acids

References:

1. Rassat, A. and P. Rey. Bull. Soc. Chim. Fr. 3, 815 (1967).
2. Barbosa, SR. et al. FEBS Lett. 446, 45 (1999).
3. Marchetto, R. et al. J. Am. Chem. Soc. 115, 11042 (1993).
4. Martin, L. et al. J. Pept. Res. 58, 424 (2001).
5. Rusiecki, VK. & SA. Warne Bioorg. Med. Chem. Lett., 3, 707 (1993).
6. Tatsu, Y. et al. In “Dynamic Studies in Biology: Phototriggers, Photoswitches and Caged. Wiley-VCH (2005)