Enzymatic formation of Glu-Xaa and Asp-Xaa bonds using Glu/Asp-specific endopeptidase from Bacillus licheniformis in frozen aqueous systems

The capability of Glu/Asp-specific endopeptidase from Bacillus licheniformi s to form Glu/Asp-Xaa bonds in frozen aqueous systems was investigated. Und er frozen state conditions, the enzyme was able to catalyse peptide bond fo rmation more effectively than in liquid reaction mixtures. The acceptance o f amino components which were completely inefficient nucleophiles at room t emperature Indicates a changed specificity of Glu/Asp-specific endopeptidas e under frozen state conditions. Protease-catalysed coupling of two acidic amino acids was demonstrated for the first time. The utilization of Glu/Asp -specific endopeptidase from Bacillus licheniformis in frozen aqueous syste ms offers new possibilities in enzyme-catalysed peptide synthesis. Copyrigh t (C) 2000 European Peptide Society and John Wiley & Sons, Ltd.