Exogenous ß-galactosidase decreased lactose in caprine mammary epithelial cells

Abstract

This study was conducted to express exogenous ß-galactosidase and make lactose hydrolyzed in mammary epithelial
cells which could provide a valuable way for obviate lactose intolerance.
PCR was used to get the 5' flanking regulatory region of bovine alpha S1 casein gene (1.2kb) from the genomic DNA and
construct the vector. ß-galactosidase was expressed under the control of 5' flanking regulatory regions of bovine alpha S1
casein gene (1.2kb) in caprine mammary epithelial cells (CMECs). LacZ gene expression specificity was detected by
5bromo-4-chloro–3-indolyl-ß-D-galactoside (X-gal) staining of the ß-galactosidase activity. In the cell culture supernatant
and cell extracts, ß-galactosidase was detected within 24 to 144 h after transfection. ß-galactosidase of the cell extracts
had a gradually decrease tendency in 24 to 72 h. In contrast, ß-galactosidase of cell culture supernatant had a gradual
increase tendency. In the cell extracts, ß-galactosidase could be detected in 1 to 3 generation. HPLC showed that the
lactose concentration of CMECs was reduced by ß-galactosidase and the effects held significantly in 24 to 144 h posttransfection.
ß-galactosidase could express in CMECs and significantly reduced the lactose concentration of CMECs,
these findings would provide an available way for obviate lactose intolerance.