Orthogonal F-Labeling for Solid-State NMR Spectroscopy Reveals the Conformation and Orientation of Short Peptaibols in Membranes.

Peptaibols are promising drug candidates in view of their interference with cellular membranes. Knowledge of their lipid interactions and membrane-bound structure is needed to understand their activity and should be, in principle, accessible by solid-state NMR spectroscopy. However, their unusual amino acid composition and noncanonical conformations make it very challenging to find suitable labels for NMR spectroscopy.

Divergent and convergent synthesis of polymannosylated dibranched antigenic peptide of the immunodominant epitope MBP(83-99).

Multiple antigenic peptide (MAP) systems are dendrimeric structures bearing multiple copies of identical or different peptide epitopes, and they have been demonstrated to show enhanced immunogenicity. Herein, we report the direct (divergent) and indirect (convergent) synthesis, using contemporary synthetic approaches, of a di-branched antigenic peptide (di-BAP) containing the immunodominant epitope MBP(83-99), which is implicated in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). The direct synthesis (di-BAP 1) was performed using microwave irradiation.

Conventional and microwave-assisted SPPS approach: a comparative synthesis of PTHrP(1-34)NH(2).

Attracted by the possibility to optimize time and yield of the synthesis of difficult peptide sequences by MW irradiation, we compared Fmoc/tBu MW-assisted SPPS of 1-34 N-terminal fragment of parathyroid hormone-related peptide (PTHrP) with its conventional SPPS carried out at RT. MWs were applied in both coupling and deprotection steps of SPPS protocol. During the stepwise elongation of the resin-bound peptide, monitoring was conducted by performing MW-assisted mini-cleavages and analyzing them by UPLC-ESI-MS.