Agilent 1100 series lc msd high performance ion trap mass spectrometer

C70PLY4 was synthesized via a solid phase method using an automated peptide synthesizer (model PS-3 from Protein Technologies, Inc.), employing the fluorenylmethoxycarbonyl (Fmoc) group for α-amino group protection. The resin used was derived from a NovaSyn TGR resin with the modified Rink linker (Merck, Darmstadt, Germany). Tryptophan and lysine residues were protected with tert-butoxycarbonyl (tBoc), and arginine residues were protected with the 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl (Pbf) group. The final de-blocking step was performed with a mixture of TFA/triisopropylsilane/water (94:3:3). The crude peptides were recovered by precipitation with diethyl ether as the non-solvent and then characterized using analytical reversed-phase HPLC. Mass spectrometry analyses were performed on an Agilent 1100 Series LC/MSD high-performance ion trap mass spectrometer to ensure that the target peptide was obtained. C70PLY4 was synthesized by Almac Sciences, UK.

Overlapping 15-mer synthetic peptides corresponding to the matured sequence of sNTX (accession: P60770) and CTX A3 (accession: P60301) were synthesized by the solid-phase method using a Prelude automated peptide synthesizer (Protein Technologies, Inc., Tucson, AZ, USA). In the process, α-amino groups were protected by the fluorenylmethoxycarbonyl group and the final de-blocking step was carried out with a mixture of TFA/triisopropylsilane/phenol/water/1,2-ethanedithiol. The crude peptide was precipitated with ether and further purified by reverse-phase HPLC. Purity was ensured to be higher than 90% by optical detector (UV 214 nm) performed on an Agilent 1100 Series LC/MSD high-performance ion-trap mass spectrometer.