1 hydroxybenzotriazole hobt

Fmoc-propargylglycine (Fmoc-D-Pra-OH) was purchased from Anaspec, USA. Fmoc-Gly and Wang resin was procured from Novabiochem, USA. 1-Hydroxybenzotriazole (HOBt) was purchased from GL Biochem, China. Oligonucleotide Primers were custom synthesized from Sigma-Aldrich, USA. PCR reagents, Taq Polymerase (Platinum HiFi) was obtained from Invitrogen, USA, Plasmid Miniprep kits, Gel extraction buffers, PCR purification kits, Ni-NTA beads, were obtained from Qaigen,USA. pET23b plasmid, T7 promoter /terminator primer was supplied by Novagen Inc., USA. All other chemicals and solvents used in the study were obtained from Sigma-Aldrich, USA.

N^α-Fmoc-protected amino acids, Fmoc-Phe, Fmoc-Val, Fmoc-Pro and Fmoc-DPro, Fmoc-Trp(Boc) and Fmoc-DTrp(Boc), Fmoc-Ser(tBu), Fmoc-Lys(Boc) and Fmoc-DLys(Boc), Fmoc-Leu and Fmoc-DLeu, Fmoc-Gly, Fmoc-Arg(Pbf), Fmoc-Nle and Fmoc-DNle, all were purchased from GL Biochem Ltd. (Shanghai, China). Other unconventional N^α-Fmoc-amino acids, namely Fmoc-Hyp(tBu) and Fmoc-DHyp(tBu), were purchased from Sigma-Aldrich (St. Louis, MO, USA), and Fmoc-Aic was acquired by Chem-Impex International (Wood Dale, IL, USA). Undecanoic, Tridecanoic, Pentadecanoic and Palmitic acids were purchased from Sigma-Aldrich. Cholesterol-PEG4 was obtained by following the synthetic procedures elsewhere reported [66 (link)]. Coupling reagents such as N,N,N′,N′-tetramethyl-O-(1H-benzo-triazol-1-yl)uronium hexafluorophosphate (HBTU) and 1-hydroxybenzotriazole (HOBt), as well as the Rink amide resin used, all were commercially obtained by GL Biochem Ltd. (Shanghai, China). N,N-diisopropylethylamine (DIEA), piperidine, and tri-fluoroacetic acid (TFA) were purchased from Iris-Biotech GMBH. Peptide synthesis solvents and reagents, such as N,N-dimethylformamide (DMF), dichloromethane (DCM), diethyl ether (Et2O), water and acetonitrile (MeCN) for HPLC, were reagent grade acquired from commercial sources (Sigma-Aldrich and VWR) and used without further purification.