Abstract
Genomic vectors containing mutant bovine β-casein with putative glycosylation sites were constructed to study the functional properties of glycosylated β-casein and its possible effects in milk. The mutation was performed by PCR-based site-directed mutagenesis. The tripeptide sequence, Asn-X-Ser, was generated between Asn 68 and Asn 73 in mature β-casein. The resulting β-casein mutants were designated pCJB68 and pCJB6873. pCJB68 carries a substitution of Ser 70 for Leu 70 (Asn 68 -Ser 69 -Ser 70 -Pro 71 ), and pCJB6873 carries a substitution of Ser 70 -Ser 71 for Leu 70 -Pro 71 (Asn 68 Ser 69 -Ser 70 -Ser 71 ). The two mutated genomic constructs were placed under control of the bovine α-lactalbumin promoter, and lines of mice expressing the pCJB68 and pCJB6873 have been established. The milk from transgenic mice contained bovine β-casein at levels up to 2-3 mg/mL. N-Linked glycosylation of bovine β-casein in the pCJB6873 line was confirmed by peptide-N-glycosidase F treatment, but glycosylation of bovine β-casein did not occur in pCJB68 mice. In addition, mouse casein micelles containing glycosylated bovine β-casein showed the largest median diameter and rough outer surface, compared to normal mouse casein micelles and micelles from transgenic milk containing bovine β-casein.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
