1. The use of Fmoc-Lys(Pac)-OH and penicillin G acylase in the preparation of novel semisynthetic insulin analogs
Lenka Záková, Daniel Zyka, Jan Jezek, Ivona Hanclová, Miloslav Sanda, Andrzej M Brzozowski, Jirí Jirácek J Pept Sci. 2007 May;13(5):334-41. doi: 10.1002/psc.847.
In this paper, we present the detailed synthetic protocol and characterization of Fmoc-Lys(Pac)-OH, its use for the preparation of octapeptides H-Gly-Phe-Tyr-N-MePhe-Thr-Lys(Pac)-Pro-Thr-OH and H-Gly-Phe-Phe-His-Thr-Pro-Lys(Pac)-Thr-OH by solid-phase synthesis, trypsin-catalyzed condensation of these octapeptides with desoctapeptide(B23-B30)-insulin, and penicillin G acylase catalyzed cleavage of phenylacetyl (Pac) group from Nepsilon-amino group of lysine to give novel insulin analogs [TyrB25, N-MePheB26,LysB28,ProB29]-insulin and [HisB26]-insulin. These new analogs display 4 and 78% binding affinity respectively to insulin receptor in rat adipose membranes.
2. Solid-phase peptide synthesis on proteins
P R Hansen, A Holm, G Houen Int J Pept Protein Res. 1993 Mar;41(3):237-45. doi: 10.1111/j.1399-3011.1993.tb00331.x.
A new method for solid-phase peptide synthesis in which a protein is used as the solid support has been developed. Two aspects of the method have been demonstrated. The peptides H-Phe-Leu-Glu-Glu-Val-OH (1) and H-Leu-Leu-Ala-Gly-Val-OH (2), respectively, were synthesized on the amino groups of BSA via a cleavable linker, using the Fmoc group protecting scheme. The free peptides were obtained by cleavage from the protein with 95% TFA, precipitation in diethyl ether and additional work-up by either dialysis or centrifugation through a membrane followed by gel filtration. The identity of the products was determined by amino acid analysis and HPLC. The peptide-protein conjugates, H-Ser-Met-Asp-Thr-Ser-Asn-Lys-Glu-Glu-Lys-BSA (3) and H-Thr-Val-Leu-BTG (4), were obtained in the same manner, omitting the cleavable linker group. It was found that 35-50 peptide chains were conjugated per molecule BSA and BTG, respectively. Immunization of rabbits with conjugate 3 gave rise to peptide specific antibodies. This method will be useful for generation of sequence specific antibodies, since the peptide is conjugated to the carrier protein exclusively via its C-terminus, and will allow synthesis of highly specific peptide-protein conjugates.
3. Asymmetric synthesis of (2S,3S)-3-Me-glutamine and (R)-allo-threonine derivatives proper for solid-phase peptide coupling
Yoshinori Tokairin, Vadim A Soloshonok, Hiroki Moriwaki, Hiroyuki Konno Amino Acids. 2019 Mar;51(3):419-432. doi: 10.1007/s00726-018-2677-5. Epub 2018 Nov 17.
Practical new routes for preparation of (2S,3S)-3-Me-glutamine and (R)-allo-threonine derivatives, the key structural components of cytotoxic marine peptides callipeltin O and Q, suitable for the Fmoc-SPPS, were developed. (2S,3S)-Fmoc-3-Me-Gln(Xan)-OH was synthesized via Michael addition reactions of Ni (II) complex of chiral Gly-Schiff base; while Fmoc-(R)-allo-Thr-OH was prepared using chiral Ni (II) complex-assisted α-epimerization methodology, starting form (S)-Thr(tBu)-OH.
