Heterologous Expression and Characterization of an N-Acetyl-beta-D-hexosaminidase from Lactococcus lactis ssp. lactis IL1403

0377491 - MBÚ 2013 RIV US eng J - Journal Article
Nguyen, A. H. - Nguyen, T.-H. - Křen, Vladimír - Eijsink, V. G. H. - Haltrich, D. - Peterbauer, C.
Heterologous Expression and Characterization of an N-Acetyl-beta-D-hexosaminidase from Lactococcus lactis ssp. lactis IL1403.
Journal of Agricultural and Food Chemistry. Roč. 60, č. 12 (2012), s. 3275-3281. ISSN 0021-8561. E-ISSN 1520-5118
R&D Projects: GA ČR(CZ) GAP207/11/0629
Keywords : N-acetyl-beta-D-hexosaminidase * Lactococcus lactis ssp lactis IL1403 * pNP-GlcNAc
Subject RIV: CE - Biochemistry
Impact factor: 2.906, year: 2012

The lnbA gene of Lactococcus lactis ssp. lactis IL1403 encodes a polypeptide with similarity to lacto-N-biosidases and N-acetyl-beta-D-hexosaminidases. The gene was cloned into the expression vector pET-21d and overexpressed in Escherichia coli BL21* (DE3). The recombinant purified enzyme (LnbA) was a monomer with a molecular weight of approximately 37 kDa. Studies with chromogenic substrates including p-nitrophenyl N-acetyl-beta-D-glucosamine (pNP-GlcNAc) and p-nitrophenyl N-acetyl-beta-D-galactosamine (pNP-GalNAc) showed that the enzyme had both N-acetyl-beta-D-glucosaminidase and N-acetyl-beta-D-galactosaminidase activity, thus indicating that the enzyme is an N-acetyl-beta-D-hexosaminidase. K-m and k(cat) for pNP-GlcNAc were 2.56 mM and 26.7 s(-1), respectively, whereas kinetic parameters for pNP-GalNAc could not be determined due to the Km being very high (>10 mM)
Permanent Link: http://hdl.handle.net/11104/0209635