Day: 30. July 2018

The group of CAO Yu used the capsid protein (HaCP) of Baculovirus expressed by E. coli and found by cryo-electron microscopy that a variety of exogenous proteins expressed at the N-terminus of HaCP could be directly fused and displayed on the outer surface. HaCP had two forms of assembly in vitro: one with a small diameter named N-tube, and another with a relatively large diameter, named W-tube. The N-tube is a helical structure similar to the TMV capsid, with 111/3 protein subunits arranged in a spiral along each circle. The W-tube is a stack of disc structures consisting of 12 protein subunits with a 11.25° rotation between adjacent discs. The interaction between the HaCP nanotube subunits was tunable, leading to high flexibility of the resulting nanotubes. HaCP nanotubes thus allow to accommodate larger guest compounds compared to assembled subunits of TMVs and thus might be  evolved into nanoscale functional molecules. CAS news release, July 30, 2018

LIU Feng and WANG Chao of the CAS Institute of Mechanics propose a theoretical framework to make use of electrical conductivity of 3D graphene foams. They combined a model of conductance between graphene sheets with a second model of the network structure of 3D graphene foams as studied by molecular dynamics simulation, and extracted geometric features such as average contact areas and contact densities. They found that as the number of layers of graphene sheets increases, the conductivity first increases and then decreases, an observation which now will be exploited experimentally. CAS news release, July 30, 2018