Patent GB-1210557-A (GB)
Title: Synthesis of polypeptides containing cysteine
Inventor: ZAHN HELMUT
IPC: C07K5/103
Filed: 1968-04-01
Abstract: 1,210,557. Disulphide peptides. FARBENFABRIKEN BAYER A.G. 1 April, 1968 [1 April, 1967; 5 Jan., 1968], No. 15469/68. Heading C2C. Single chain polypeptides with at least one cysteine residue are prepared by (1) synthesis of a first symmetrical cystinyl peptide consisting of 2 identical amino acid sequences corresponding to one portion of the desired single chain peptide linked by at least one -S-S- bond by incorporating a cystine residue at at least one point where the cysteine residue occurs in the desired peptide; (2) preparing a di- or polymeric intermediate consisting of two or more of the desired polypeptide chains linked by at least one cistinyl -S-S- bond by (a) coupling a second symmetrical cystinyl peptide consisting of 2 amino acid sequences corresponding to the remaining portion of the desired single chain polypeptide with the first symmetrical peptide to give a polymeric intermediate consisting of a number of the desired polypeptide chains linked by cystinyl -S-S- bands; or (b) coupling a single chain consisting of an amino acid sequence corresponding to the remaining portion of the desired single chain polypeptide with the first symmetrical peptide to give a dimeric intermediate consisting of 2 of the desired polypeptide chains linked by at least one cystinyl -S-S- bond; and (3) splitting the -S-S- bonds of the intermediate. The synthesis of insulin by the above method is described and intermediates isolated are (Z - Cys - Gly - OMe) 2 ; (Z - Leu - Cys - Gly- OMe) 2 ; (Z - His - Leu - Cys - Gly - OMe) 2 ; (Z - Gln - His - Leu - Cys - Gly - OMe) 2 ; (ZAsn - Gln - His - Leu - Cys- Gly - OMe)2; (Z - Val - Asn - Gln - His - Leu - Cys - Gly- OMe) 4 ; (Z - Phe - Val - Asn - Gln - His - Leu- Cys - Gly OMe) 2 ; (Z - Phe - Val - Asn - Gln- His - Leu - Cys - Gly - N 2 H 3 ) 2 ; Z - Ser(But)- His - Leu - Val - Glu(OBut) - N 2 H 3 ; Z - Ser (But) - His - Leu - Val - Glu(OBut) - Ala - Leu- Tyr(But) - OMe; (Z - Val - Cys - Gly - OMe) 2 ; (Z - Leu - Val - Cys - Gly - OMe) 2 ; (Tri - Leu- Val - Cys - Gly - OMe) 2 ; (Tri - Leu - Val - Cys- Gly - OH) 2 ; (Tri - Leu - Val - Cys - Gly- N 2 H 3 ) 2 ; (Tri - Leu - Val - Cys - Gly - Glu (OBut) - Arg - Gly - OH) 2 ; (Tri - Leu - Val- Cys - Gly - Glu(OBut) - Arg - Gly - Phe - Phe- Tyr(But) - Thr(But) - Pro - Lys(BOC) - Ala- OBut) 2 ; (Z - Phe - Val - Asn - Gln - His Leu- Cys - Gly - Ser(But) - His - Leu - Val - Glu (OBut) - Ala - Leu - Tyr(But) - OMe) 2 ; (Z - Cys- Ala - Gly - OMe) 2 ; (BOC - Cys(TR1) - Cys- Ala - Gly - OMe) 2 ; (BOC - Gln - Cys(TR1) - Cys- Ala - Gly - OMe) 2 ; (BOC - Gly - Ile - Val- Glu(OBut) - Gln - Cys(TRl) - Cys - Ala - Gly- OMe) 2 ; (BOC - Gly - Ile - Val - Glu(OBut). Gin - Cys(TRl) - Cys - Ala - Gly - N 2 H 3 ) 2  (BOC - Cys - ONp) 2 ; (BOC - Cys - Asn - OBz) 2 ; (BOC - Tyr(Bz) - Cys - Asn - OBz) 2 ; (BOCAsn - Tyr(Bz) - Cys - Asn - OBz) 2 ; (BOCGlu(OBz) - Asn - Tyr(Bz) - Cys - Asn - OBz) 2 ; (Trl - Leu - Tyr(But) - Gln - Leu - Glu(OBz)- Asn - Tyr(Bz) - Cys - Asn - OBz) 2 ; and (TR1- Val - Cys(TR1) - Ser- Leu - Tyr - Gln - Leu- Glu(OBz) - Asn - Tyr(Bz) - Cys - Asn - OBz) 2 .