| abstract |
This invention relates to dipeptidase of lactic acid bacteria in isolated form, characterized by a molecular weight of 55 kD ± 5 kD; an isoelectric point of 4.4 ± 0.4; a substrate range including the dipeptides leu-leu, leu-met, leu-val, leu-gly, val-leu, phe-leu and ala-ala, but not the dipeptides his-leu, γ-glu-leu, gly-leu, α-glu-ala and peptides of 3 or more amino acid residues; and a hydrolyzing activity with a temperature optimum at 50°C ± 10°C, a pH optimum at 8 ± 1, and sensitivity to the metal chelating EDTA and to the reducing agents dithiotreitol and mercaptoethanol. The invention also relates to a process for isolating the dipeptidase from lactic acid bacteria; to the use of the dipeptidsae for preparing polyclonal or monoclonal antibodies having an affinity to, and/or specificity for, the dipeptidase; to polyclonal and monoclonal antibodies having an affinity to, and/or specificity for, the dipeptidase; to the use of polyclonal or monoclonal antibodies for detecting the dipeptidase in, or removing or isolating it from, a mixture containing the dipeptidase; to the use of the dipeptidase in the production of food products, and to food products produced using the dipeptidase. |