Laboratory Detection and Diagnosis of Filoviruses / 中国病毒学·英文版

Ebola virus(EBOV)and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.

Fusion Immunotoxin Anti-HER-2-scFv-SEC2 Expressed in E.coli With an Improved Expression Vector pASK75-EX: Its Construction and Functioning / 生物化学与生物物理进展

A tumor-targeting recombinant fusion immunotoxin B-L-SEC2 was constructed by fusing staphylococcal enterotoxin C2 (SEC2) and an anti-HER-2 single-chain Fv B1 through a peptide linker, and expressed in E. coli strain BL21 (DE3) with an improved expression vector pASK75-EX as inclusion body. The denatured inclusion body was purified with Ni-NTA chelate agarose, and then re-natured by dialysis. FACS and MTT assays indicated that the re-natured fusion immunotoxin B-L-SEC2 could target the HER-2 over-expressing breast tumor cell SK-Br-3 in vitro, and inhibit the growth of SK-Br-3.

Observation of The Interaction Between MutS and MutL Mismatch Repair Proteins by Fusion Protein Systems / 生物化学与生物物理进展

MutL and MutS or their homologues are two crucial proteins of DNA mismatch repair (MMR) system. A new method was described for observation of the interaction between MutS and MutL which is based on the fusion gene/fusion protein technique. Three fusion proteins, MutL-GFP fusion (Trx-His6-GFP-(Ser-Gly)6-MutL), MutL-Strep tag Ⅱ fusion (Trx-His6-(Ser-Gly)6-Strep tagⅡ-(Ser-Gly)6-MutL) and MutS fusion (Trx-His6-(Ser-Gly)6-MutS), were constructed and expressed in E. coli AD494 (DE3). Interaction assay between MutS and MutL was performed in a 96-well microtiter plate.MutS fusion protein was immobilized on the wells and provided a surface for the interaction between MutS and MutL.Results showed that only after binding of MutS to the mismatched DNA, there was an interaction between MutS and MutL.The binding events could be indicated by GFP signal or the signal generated from alkaline phosphatase and its substrate. In addition, the method based on fusion molecular system also serve as a model for studies on the interactions among other proteins or biomolecules.