MODIFIED ß-GALACTOSIDASE

The usefulness of β-galactosidases derived from Bacillus circulans is further enhanced so that they can be applied to new applications. The present invention provides a modified β-galactosidase in which one or more amino acids selected from the group consisting of proline at position 182 (P182), tyrosine at position 187 (Y187), serine at position 188 (S188), tryptophan at position 405 (W405), alanine at position 406 (A406), glutamine at position 407 (Q407), tyrosine at position 449 (Y449), threonine at position 483 (T483), serine at position 512 (S512), serine at position 531 (S531), serine at position 533 (S533), serine at position 534 (S534), asparagine at position 550 (N550), glutamine at position 551 (Q551), tryptophan at position 593 (W593), tyrosine at position 598 (Y598), proline at position 602 (P602), proline at position 604 (P604), tyrosine at position 609 (Y609), lysine at position 612 (K612), and tyrosine at position 615 (Y615), or an amino acid(s) corresponding thereto, has/have been substituted by other amino acid in a β-galactosidase consisting of the amino acid sequence of any of SEQ ID NOs. 1 to 4 or an amino acid sequence having 90% or more identity to the amino acid sequence set forth in any of SEQ ID NOs. 1 to 4.