Total synthesis of bovine pancreatic ribonuclease A. Part 3. Synthesis of the protected hexapentacontapeptide ester (positions 69–124)

1 January 1981

journal article
research article
Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 1

No. 3,p. 804-810
https://doi.org/10.1039/p19810000804

Abstract

Commencing with the protected hexatriacontapeptide, corresponding to the sequence of bovine pancreatic RNase A, Z(OMe)-(RNase 89–124)-OBzl, chain elongation was carried out to the hexapentacontapeptide stage, Z(OMe)-(RNase 69–124)-OBzl, by six successive azide condensations of the peptide fragments Z(OMe)-Asp-(OBzl)-Cys(MBzl)-Arg(MBS)-Glu(OBzl)-Thr-Gly-NHNH-Troc (10), Z(OMe)-Ser-Ile-Thr-NHNH₂(11), Z(OMe)-Ser-Thr-Met(O)-NHNH₂(12), Z(OMe)-Gln-Ser-Tyr-NHNH₂(13), Z(OMe)-Asn-Cys(MBzl)-Tyr-NHNH₂(14), and Z(OMe)-Gln-Thr-NHNH₂(15). The Troc group was removed from fragment (10) by treatment with Zn prior to condensation. With N-methylpyrrolidone-5% H₂O as eluant, gel-filtration on Sephacryl S-200 was employed for purification of Z(OMe)-(RNase 69–124)-OBzl which was contaminated with the acyl component used in excess during the coupling.