Solid-phase peptide synthesis and solid state NMR analysis of GRF(1-29)

Solid-phase peptide synthesis (SPPS) has been proven to be a reliable technique for research purposes and pharmaceutical drug production. SPPS is known to give high synthesis yields for short peptides, but the yield drastically drops for peptides with longer amino acid sequences (>40 residues). This issue has been hypothesized to be caused by the incomplete coupling reactions of amino acid residues to the terminal of a peptide sequence during SPPS.  However, the details of this process are largely unknown as structural analysis for proteins and peptides in SPPS is limited due to the solid support used in the synthesis. A legit approach to this problem can be achieved by using a novel solid state NMR (SSNMR), which is capable of identifying protein/peptide structures by SPPS method. In this study we focused on the optimization of synthesis for a 29-residue fragment of hypothalamic Growth Hormone Releasing Factor, GRF(1-29). Based on mass spectroscopy results of the synthesized GRF(1-29), pure peptide samples were achieved. Our preliminary SSNMR analysis indicated that structural analysis of GRF(1-29) is feasible.  Such synthesis and structural analysis has promising research on the study of a variety of peptides to work with in the future to come.