Influence of low-molecular-weight aggregates on aggregate growth kinetics and physical properties of solid-state proteins during storage.

Low-molecular-weight (LMW) aggregate is a critical determinant of subsequent protein aggregation, but the aggregate growth kinetics of solid proteins have not been fully characterized. In this study, the high-molecular weight (HMW) aggregate formation process for solid-state proteins and the relationship between aggregation and physical properties of tablets were evaluated using proteins with various initial aggregate ratios. Quantitative changes in monomers, LMW aggregates, and HMW aggregates during storage were measured.

Characterization of KfrA proteins encoded by a plasmid of Paenibacillus popilliae ATCC 14706(T).

A scaffold obtained from whole-genome shotgun sequencing of Paenibacillus popilliae ATCC 14706(T) shares partial homology with plasmids found in other strains of P. popilliae. PCR and sequencing for gap enclosure indicated that the scaffold originated from a 15,929-bp circular DNA.

Mass Production of an Active Peptide-N-Glycosidase F Using Silkworm-Baculovirus Expression System.

The peptide-N (4)-(N-acetyl-β-D-glucosaminyl) asparagine amidase F (PNGase F) catalyzes the cleavage of N-linked oligosaccharides between the innermost GlcNAc and asparagine residues of high mannose, hybrid and complex oligosaccharides from glycoproteins. The PNGase F has broad substrate specificity and thus is extensively used for the structural and functional studies of the glycoproteins. In this study, we tried to produce active recombinant PNGase F as secreted and intracellular-expressed forms using baculovirus expression vector system (BEVS) through silkworm larvae or cultured cells.

Biochemical characterization of maintenance DNA methyltransferase DNMT-1 from silkworm, Bombyx mori.

DNA methylation is an important epigenetic mechanism involved in gene expression of vertebrates and invertebrates. In general, DNA methylation profile is established by de novo DNA methyltransferases (DNMT-3A, -3B) and maintainance DNA methyltransferase (DNMT-1). DNMT-1 has a strong substrate preference for hemimethylated DNA over the unmethylated one.

Expression, purification, and characterization of endo-β-N-acetylglucosaminidase H using baculovirus-mediated silkworm protein expression system.

Endo-β-N-acetylglucosaminidase (Endo H) from Streptomyces plicatus hydrolyzes the core di-GlcNAc units of asparagine-linked oligosaccharides and is regarded as an important tool for glycobiology research. In the present study, we established a large-scale system to produce secreted Endo H using a silkworm-baculovirus expression system (silkworm-BES). The recombinant Endo H purified from silkworm hemolymph had activity comparable to that from recombinant Escherichia coli.

Establishment of a soaking RNA interference and Bombyx mori nucleopolyhedrovirus (BmNPV)-hypersensitive cell line using Bme21 cell.

The double-stranded RNA (dsRNA) mediated RNA interference (RNAi) is widely employed in silkworm and its tissue-derived cell lines for gene function analysis. Baculovirus expression vector system (BEVS) has an advantage for large-scale protein expression. Previously, combining these useful tools, we improved traditional AcMNPV-Sf9 BEVS to produce modified target glycoproteins, where the ectopic expression of Caenorhabditis elegans systemic RNAi defective-1 (SID-1) was found to be valuable for soaking RNAi.