Subtilisin 72 serine protease (EC 3.4.21.14) immobilized on a poly(vinyl alcohol) cryogel was used as a catalyst in the syntheses of N-protected peptide p-nitroanilides of the general formulas Z(or Boc)-Xaa-Phe-pNA (Xaa = Leu or Ala), Z-Ala-Xaa-Yaa-pNA (Xaa = Leu or Ala; Yaa = Leu or Phe), and Z-Ala-Ala-Xaa-Yaa-pNA (Xaa = Leu, Arg, or Gly; Yaa = Phe, Leu, Gly, Asp, or Glu). The syntheses were carried out in DMF-acetonitrile mixtures. A number of protected di-, tri-, and tetrapeptides were prepared in yields up to 99%. The syntheses were found to retain stereoselectivity under the conditions studied. The activation of carboxyl group of the acylating component was shown to have a positive effect upon the coupling rate.
将固定于聚
乙烯醇冻胶上的72
丝氨酸蛋白酶(
EC 3.4.21.14)用作合成N-保护肽对
硝基苯胺的
催化剂,其通式为Z(或Boc)-Xaa-Phe-pNA(Xaa=亮
氨酸或丙
氨酸)、Z-Ala-Xaa-Yaa-pNA(Xaa=亮
氨酸或丙
氨酸;Yaa=亮
氨酸或
苯丙
氨酸)和Z-Ala-Ala-Xaa-Yaa-pNA(Xaa=亮
氨酸、精
氨酸或甘
氨酸;Yaa=
苯丙
氨酸、亮
氨酸、甘
氨酸、
天冬氨酸或谷
氨酸)。合成在
DMF-
乙腈混合物中进行。制备了一系列二肽、三肽和四肽保护物,收率高达99%。研究发现,在所研究的条件下,合成保留了立体选择性。酰化成分羧基的活化对偶联率有积极影响。