title: Thermolysin as a catalyst in enzymatic synthesis of asparagine-containing peptides II.
abstract: Thermolysin was used as a catalyst to obtain the following protected di- and tripeptide esters: Z-Asn-Leu-OEt, Z-Asn-Phe-OEt, Moz-Asn-Leu-Gly-OEt, Boc-Asn-Leu-Gly-OEt, Z-Asn-Leu-Gly-OEt, Moz-Asn-Leu-Gly-OBzl, Moz-Asn-Leu-Gly-OtBu, Moz-Gln-Leu-Gly-OEt, Moz-Asn-Ile-Gly-OEt, and Moz-Asn-Leu-Ala-OEt. These compounds were obtained in pure form and the yields exceeded 50%, except for Moz-Asn-Leu-Gly-OtBu and Boc-Asn-Leu-Gly-OEt. H-Cys(Bzl)-OtBu and H-Cys(Bzl)-Pro-Leu-Gly-NH2 were both inadequate as amino components for obtaining Moz-Asn-Cys(Bzl)-OtBu, Z-Asn-Cys(Bzl)-OtBu and Moz-Asn-Cys(Bzl)-Pro-Leu-Gly-NH2 in the thermolysin-catalyzed reactions. In the attempted synthesis of the protected pentapeptide amide, this protease cleaved the Pro-Leu bond of the amino component H-Cys(Bzl)-Pro-Leu-Gly-NH2 and catalyzed the coupling between the resulting dipeptide amide and Moz-Asn-OH, thus yielding Moz-Asn-Leu-Gly-NH2 as the main product.
authors.affiliation: Department of Biochemistry, University of São Paulo, Brazil.
authors.forename: M T
authors.initials: MT
authors.lastname: Miranda
authors.forename: M
authors.initials: M
authors.lastname: Tominaga
mesh_terms: D000595:Amino Acid Sequence; D001216:Asparagine; D002384:Catalysis; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000096:biosynthesis*; D013820:Thermolysin / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D001216:Asparagine; D013820:Thermolysin