Patent ID: 6465209
Filing Date: 2002-10-15
Classification: A21D,A23J,A23L,C12N,C12P

Abstract:
A method of producing a protein hydrolysate, comprising adding to a proteinaceous material one or more polypeptides having glycine-releasing activity and one or more additional proteases wherein the amount of glycine produced is greater than the amount of glycine produced by the one or more additional proteases alone under the same conditions. wherein the one or more polypeptides having glycine-releasing activity are obtained from an Aspergillus and/or Sphingomonas strain selected from the group consisting of:(a) a polypeptide having an amino acid sequence which has at least 90% identity with SEQ ID NO. 2 or SEQ ID NO. 11; (b) a polypeptide encoded by a nucleic acid sequence which hybridizes under medium stringency conditions with (i) the nucleic acid sequence of SEQ ID NO. 1 or SEQ ID NO. 10, or (ii) its complementary strand, wherein medium stringency conditions are defined as prehybridization and hybridization at 42Â° C. in 5Ã—SSPE, 0.3% SDS, 200 &mgr;g/ml sheared and denatured salmon sperm DNA, and 35% formamide; (c) a fragment of (a) or (b), wherein the fragment has aminopeptidase activity; (d) a polypeptide having aminopeptidase activity with physicochemical properties of (i) a pH optimum in the range of about pH 7.27 to about pH 10.95 determined at ambient temperature in the presence of Ala-para-nitroanilide; (ii) a temperature stability of 90% or more, relative to initial activity, at pH 7.5 determined after incubation for 20 minutes at 60Â° C. in the absence of substrate; and (iii) aminopeptidase activity against Xaa-para-nitroanilide wherein Xaa is selected from the group consisting of Leu, Glu, Gly, Ala, and Pro; and (e) a polypeptide having aminopeptidase activity with physicochemical properties of (i) a pH optimum in the range of about pH 5.0 to about 8.5 measured at 37Â° C., (ii) an isoelectric point in the range of 7.4-8.5; (iii) has aminopeptidase activity in the temperature range of 20-55Â° C., measured at pH 7.5 using Gly-pNA in Tris-HCl buffer; (iv) hydrolyzes Ala-pNA, Gly-pNA, Leu-pNA, Glu-pNA, Asp-pNA, Lys-pNA, Ile-pNA and Val-pNA; (e) does not hydrolyze Phe-pNA or Pro-pNA; and (v) is not inhibited by phenylmethanesulfonyl fluoride, and completely inhibited by o-phenanthroline.