The invention relates to a method for preparing a coupling product having the sequence Pq-Wv-His-X-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Y-Glu-Phe-Ile-Ala-Trp-Leu-Val-Z-Gly-Arg-Gly. The method includes enzymatically coupling
(a) a peptide C-terminal ester or thioester having a first peptide fragment represented by the formula Pq-Wv-His-X-Glu-(thio)ester; and
(b) a peptide nucleophile having an N-terminally unprotected amine having a second peptide fragment with the sequence H-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Y-Glu-Phe-Ile-Ala-Trp-Leu-Val-Z-Gly-Arg-Gly
wherein
P represents a protective group at the N-terminal α-amino function of the peptide C-terminal ester or thioester and q is an integer having a value of 1 or 0;
W represents one or more amino acid residues, which may be the same or different and v is an integer having a value of 1 or more representing the number of amino acid residues W;
X is Ala or an α-amino-isobutyric acid unit (Aib);
Y is Lys, which Lys has a free side-chain ε-amino group or a side-chain ε-amino group that is protected with a protective group or a side-chain ε-amino group that is functionalized with an amino acid or another functional group; and
Z is Arg or Lys.
本发明涉及一种制备具有 Pq-Wv-His-X-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Y-Glu-Phe-Ile-Ala-Trp-Leu-Val-Z-Gly-Arg-Gly 序列的偶联产物的方法。该方法包括将
(a) 具有由式 Pq-Wv-His-X-Glu-(thio)ester 代表的第一肽片段的肽 C 端酯或
硫酯;和
(b) 具有 N 端未受保护的胺的肽亲核体,其第二肽片段的序列为 H-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Y-Glu-Phe-Ile-Ala-Trp-Leu-Val-Z-Gly-Arg-Gly
其中
P 代表肽 C 端酯或
硫酯的 N 端 α-
氨基官能团的保护基团,q 是数值为 1 或 0 的整数;
W 代表一个或多个
氨基酸残基,它们可以相同或不同,v 是一个数值为 1 或以上的整数,代表
氨基酸残基 W 的数目;
X 是 Ala 或 α-
氨基
异丁酸单元(Aib);
Y 是 Lys,其中 Lys 具有一个游离侧链 ε-
氨基基团,或一个用保护基团保护的侧链 ε-
氨基基团,或一个用
氨基酸或其他官能团官能化的侧链 ε-
氨基基团;和
Z 是 Arg 或 Lys。