ABSTRACT
1H-Benzotriazolium 1-[bis(dimethyl-amino)methylene]-5-chloro-hexafluorophosphate (1-),3-oxide (HCTU) is a nontoxic, nonirritating and noncorrosive coupling reagent. Seven biologically active peptides (GHRP-6, (65-74)ACP, oxytocin, G-LHRH, C-peptide, hAmylin(1-37), and beta-amyloid(1-42)) were synthesized with reaction times reduced to deprotection times of 3 min or less and coupling times of 5 min or less using HCTU as the coupling reagent. Expensive coupling reagents or special techniques were not used. Total peptide synthesis times were dramatically reduced by as much as 42.5 h (1.8 days) without reducing the crude peptide purities. It was shown that HCTU can be used as an affordable, efficient coupling reagent for fast Fmoc solid-phase peptide synthesis.
Subject(s)
Amyloid/chemistry , Peptide Biosynthesis , Peptides/chemical synthesis , Triazoles/chemistry , Amino Acid Sequence , Amyloid beta-Peptides/chemistry , Chromatography, High Pressure Liquid/methods , Gonadotropin-Releasing Hormone/chemistry , Humans , Islet Amyloid Polypeptide , Molecular Sequence Data , Oxytocin/chemistry , Peptides/chemistry , Time FactorsABSTRACT
Human amylin (1-37) and the (1-13) fragment were synthesized with and without pseudoproline dipeptides. Thallium (III) trifluoroacetate, a mild oxidant, was used to cyclize the peptides by forming a disulfide bridge from C(2) to C(7). On the basis of our model studies, incorporation of a pseudoproline dipeptide decreases the amount of time necessary for the crude linear amylin (1-13) to cyclize on the resin. Without pseudoproline dipeptides, the 1-37 crude linear amylin was not pure enough to undergo the cyclization reaction. Following the cyclization studies, the synthesis time of the linear human amylin (1-37) was systematically reduced from 58 h to 8.5 h by shortening the reaction times. Cyclization and cleavage times were also reduced to 1.5 h.
