Peptide Synthesis and Characterization

The peptides PSELT (H-Phe-Gln-Ile-Cys-Val-Ser-Sec-Gly-Tyr-Arg-OH), [Ser46,49] PSELT [called inert PSELT (I-PSELT) as a control], and PSELT-dansyl were synthesized by Fmoc solid phase methodology on an automated peptide synthesizer (CEM, Saclay, France) as previously described [19 (link)]. KCl, NaCl, NaHCO₃, CaCl₂, MgSO₄, KH₂PO₄, NaH₂PO₄, Na₂HPO₄, mannitol, glucose, Na-pyruvate, β-nicotinamide adenine dinucleotide (NADH), reduced disodium salt hydrate, 2,4 dinitrophenylhydrazine (DNPH), 2-thiobarbituric acid (TBA), bovine serum albumin (BSA), butylated hydroxyanisole, diethyl ether, ethylenediaminetetraacetic acid (disodium salt), diethylenetriamine pentaacetic acid, pyrogallol, streptomycin sulfate, tween-20, hydrogen peroxide (H₂O₂), and urea were purchased from Sigma Aldrich (St. Louis, MO, USA). Tunicamycin (TM) was from Cayman Chemical (Ann Arbor, MI, USA), Dulbecco’s Modified Eagle Medium/Nutrient Mixture F-12 (DMEM/F-12), penicillin/streptomycin and fetal bovine serum (FBS) were provided by Thermo Fisher Scientific (Waltham, MA, USA). All the solutions were freshly prepared before starting the experiments. Absolute ethanol, ethyl acetate, hydrochloric acid, methanol, and trichloroacetic acid (TCA) were from Carlo Erba Reagents (Cornaredo, Milano, Italy).