Silkworm expression system as a platform technology in life science

Many recombinant proteins have been successfully produced in silkworm larvae or pupae and used for academic and industrial purposes. Several recombinant proteins produced by silkworms have already been commercialized. However, construction of a recombinant baculovirus containing a gene of interest requires tedious and troublesome steps and takes a long time (3–6 months). The recent development of a bacmid, Escherichia coli and Bombyx mori shuttle vector, has eliminated the conventional tedious procedures required to identify and isolate recombinant viruses. Several technical improvements, including a cysteine protease or chitinase deletion bacmid and chaperone-assisted expression and coexpression, have led to significantly increased protein yields and reduced costs for large-scale production. Terminal N-acetyl glucosamine and galactose residues were found in the N-glycan structures produced by silkworms, which are different from those generated by insect cells. Genomic elucidation of silkworm has opened a new chapter in utilization of silkworm. Transgenic silkworm technology provides a stable production of recombinant protein. Baculovirus surface display expression is one of the low-cost approaches toward silkworm larvae-derived recombinant subunit vaccines. The expression of pharmaceutically relevant proteins, including cell/viral surface proteins, membrane proteins, and guanine nucleotide-binding protein (G protein) coupled receptors, using silkworm larvae or cocoons has become very attractive. Silkworm biotechnology is an innovative and easy approach to achieve high protein expression levels and is a very promising platform technology in the field of life science. Like the “Silkroad,” we expect that the “Bioroad” from Asia to Europe will be established by the silkworm expression system

TiCrVMo alloys with high dissociation pressure for high-pressure MH tank

High-pressure metal hydride (MH) tank is a possible hydrogen storage system for fuel cell vehicles. The merit of the high-pressure MH tank system is improved by the use of a metal hydride with high dissociation pressure. In this study, TiCrV and TiCrVMo alloys with BCC structure has been developed for the high-pressure MH tank system. The developed TiCrVMo alloy shows 2.4 mass% of effective hydrogen capacity between 0.1 MPa and 33 MPa at 298 K, which has a dissociation pressure of 2.3 MPa at 298 K. By investigating the dissociation pressures of the synthesized metal hydrides, it is found that Mo has a special effect to increase dissociation pressure of the metal hydrides. This effect is probably attributed to the large bulk modulus of Mo compared to other elements