National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2013

20. Molecular cloning and expression of the α-glucosidase II from Bombyx mori.

Japanese

Bombyx mori is used as a bioreactor for the production of heterologous recombinant proteins because it offers distinct advantages such as high yield of protein production and post-translational modifications similar to those in vertebrates. The α-glucosidase II (GII) is a heterodimer of α- and β-subunits and important for N-glycosylation processing and quality control of nascent glycoproteins. However, the genes for B. mori GII subunits have not yet been identified, and the protein has not been characterised. Therefore, we first isolated the GII α- and β-subunit genes and produced recombinant GII subunits using the baculovirus expression system, and then identified the characteristics of the enzyme. The recombinant GII α-subunit hydrolysed p-nitrophenyl α-D-glucopyranoside (pNP-αGlc) but was inactive toward N-glycan. Although the B. mori GII β-subunit was not required for the hydrolysis of pNP-αGlc, a B. mori GII complex of the α- and β-subunits was required for N-glycan cleavage. Our results may aid in better understanding the role of GII in N-glycosylation processing in B. mori.
(Pathology and Pathophysiology Research Division)

References:

Watanabe S. et al (2013) Insect Biochem. Mol. Biol. 43:319-327

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