Recombinant beta-galactosidase derived from Streptococcus pneumaniae

Abstract

The present invention relates to a novel beta-galactosidase derived from Streptococcus pneumoniae , a BgaC protein exhibiting the enzyme activity, and a method for using the same. The protein can be used in the modification and analysis of sugar chain and used as an anti-cancer agent.

1 . A protein exhibiting beta-galactosidase enzyme activity, which has an amino acid sequence represented by SEQ ID NO: 2, or an amino acid sequence having at least 90% homology therewith. 
     
     
         2 . The protein according to  claim 1 , wherein the beta-galactosidase selectively hydrolyzes the galactose in the structure of galactose-β1, 3-N-acetylglucosamine. 
     
     
         3 . The protein according to  claim 1 , which has the following characteristics of (a) to (d):
 (a) maximum activity in the temperature range of 20 to 40° C.;   (b) maximum activity at a pH range of 5.0 to 8.0;   (c) a molecular weight of 50 to 100 kDa; and   (d) more reactivity and higher substrate specificity to PNPG than to ONPG.   
     
     
         4 . An isolated nucleic acid molecule encoding the protein of  claim 1 . 
     
     
         5 . An expression vector comprising the nucleic acid molecule of  claim 4 . 
     
     
         6 . The expression vector according to  claim 5 , shown in  FIG. 1B . 
     
     
         7 . A transformant transformed by the expression vector of  claim 6 . 
     
     
         8 . The transformant according to  claim 7 , which has a deposit number of KCTC10956BP. 
     
     
         9 . A method for linkage-specifically cleaving the galactose and modified sugar chain in the structure of galactose-beta 1,3-N-acetylglucosamine using the protein according to any one of  claims 1  to  3 . 
     
     
         10 . A method for linkage-specifically analyzing the structure of a sugar chain by treating with the protein according to any one of  claims 1  to  3 . 
     
     
         11 . A composition for inhibiting tumor, comprising the protein according to any one of  claims 1  to  3  as an active ingredient.