1. Synthesis of human proinsulin sequence 71-86, II: Improved synthesis of the fragment
N A Sasaki Hoppe Seylers Z Physiol Chem. 1979 Jun;360(6):761-4. doi: 10.1515/bchm2.1979.360.1.761.
An improved synthesis of a fully protected hexadecapeptide Bpoc-Cys(Trt)-Cys-(Trt)-Thr(But)-Ser(But)-Ile-Cys(Trt)-Ser(But)-Leu-Tyr(But)-Gln-Leu-Glu(OBut)-Asn-Tyr(But)-Cys(Trt)-Asn-OBut, which corresponds to the amino acid sequence 71-86 of human proinsulin, is described. The final product was obtained by the condensation of three fragments 71-74, 75-77 and 78-86.
2. Human proinsulin VI. Synthesis of protected segment 46-70 of prohormone
V K Naithani, E Schwertner Hoppe Seylers Z Physiol Chem. 1983 Nov;364(11):1603-13. doi: 10.1515/bchm2.1983.364.2.1603.
The synthesis of the protected pentacosapeptide Trt-Gly-Gly-Pro-Gly-Ala-Gly-Ser-(But)-Leu-Gln-Pro-Leu-Ala-Leu-Glu( OBut)-Gly-Ser (But)-Leu-Gln-Lys(Boc)-Arg-Gly-Ile-Val-Glu-(OBut)-Gln-OH (Pos. 46-70) of human proinsulin is described. This segment was prepared by the mixed anhydride condensation of the trityl-protected peptides (46-64) or (46-59) with the fragments 65-70 and 60-70, respectively. In both the cases the purification was effected by counter current distribution in a yield of 25% and 24%, respectively.
3. Human proinsulin, V: synthesis of a protected peptide fragment corresponding to the sequence 24-45 of the prohormone
J Föhles, W Danho Hoppe Seylers Z Physiol Chem. 1980;361(6):849-56. doi: 10.1515/bchm2.1980.361.1.849.
The protected peptide fragment 24-45 of human proinsulin, Bpoc-Phe-Phe-Tyr(But)-Thr-(But)-Pro-Lys(Boc)-Thr(But)-Arg(H2SO4)-Arg-(H2SO4)-Gl u(OBut)-Ala-Glu(OBut)-Asp(OBut)-Leu-Gln-Val-Gly-Gin-Val-Glu(OBut)-Leu-Gly-Oh, was synthesized from the two intermediate fragments 24--33 and 34--45, and purified by countercurrent distribution in the carbon tetrachloride system (K = 2.5).
