Mapping the interaction site of prion protein and Sho.

The cellular prion protein (PrP(C)) is a highly conserved protein among mammals and is considered to have important cellular functions. Despite decades of intensive research, however, the physiological function of PrP(C) remains unclear. Sho (Shadoo, shadow of prion protein) and PrP(C) have similar N-terminals, which suggests that the two proteins share biological functions. Using truncation mutants of both proteins and yeast two-hybrid analysis, with validation by co-immunoprecipitation and surface plasmon resonance (SPR), we have identified an interaction between Sho 61-77 and PrP(C) 108-126 domains. This indicates that Sho may play a role in the physiological function of PrP(C) and prion pathogenesis.

A rapid method for detection of PrP by surface plasmon resonance (SPR).

Surface plasmon resonance was used to develop a rapid, label-free and sensitive immunoassay for detection of Prion protein (PrP). Anti-PrP monoclonal antibodies immobilized on the biosensor surface were allowed to bind various concentrations of cellular prion protein (PrP(C)), followed by a pulse with additional soluble anti-PrP polyclonal antibodies to intensify the signal. The interaction of antibody with antigen was monitored in real time. With this method, it was possible to detect PrP(C) with a limit of 31.7 ng/ml in serum and 13.1 ng/ml in HEPES-saline, requiring 1 h for a single sample measurement. The assay also detected misfolded prion protein (PrP(Sc)) in spiked serum and PrP(Sc) in scrapie-infected mouse brains. This is a rapid and sensitive assay for the detection of PrP in serum that could be developed into a platform for a serum-based TSE test.

Study on the production efficiency of platelet components in 24 prefecture-level blood stations in China / 中国输血杂志

【Objective】 To learn the production efficient of platelet components among prefecture-level blood stations in China, to provide supporting data for those blood stations to optimize the production mode of platelet components and continuously improve production efficiency and supply capacity. 【Methods】 The data from 2017 to 2020 was obtained from 24 prefecture-level blood stations who were the members of the practice comparison network for blood institutes in China. The collection units of apheresis platelets, the number of dual-collections of apheresis platelets and plasma, the average apheresis units of one platelet apheresis procedure, the discarded rate of apheresis platelets, the amount of expired apheresis platelets and the amount of apheresis platelets issued were collected. For concentrated platelets, the prepared amount of platelet concentrates and the amount of expired platelet concentrates were collected; both the quantity of qualified and issued concentrated platelets were submitted for statistical analysis.The total output and efficiency of platelet components were calculated based on the collected data. 【Results】 The average annual growth rate of apheresis platelets collection in 24 prefecture-level blood stations was 12.23%, accounting for 99.80% of the total platelet output; the average collection unit of one platelets apheresis procedure was 1.75; from 2019 to 2020, only 5 blood stations performed dual-collection of platelet and plasma during one apheresis procedure; the discarded rate of apheresis platelets was 0.28%, of which 0.007% was due to expiration. A total of 1 621.2 therapeutic units of concentrated platelets were prepared, and 13.03% of them was discarded due to the expiration. The production efficiency of platelet components was 97.56%, of which the production efficiency of apheresis platelets was 97.61% and the production efficiency of concentrated platelets was 74.43%. 【Conclusion】 There are large regional differences in the supply capacity of platelet components in prefecture-level blood stations. Apheresis platelets are the main resource of platelet components product, and the collection capacity is increasing over the years with the characteristics of high production efficiency and low expiration scrapping rate. However, the preparation of concentrated platelets are still limited with relatively low production and high expiration discarded rate.

Toxic effect of oral ricin on the mouse intestinal tract and immune organs / 中国兽医学报

The experiment aimed to study the toxic effect of oral ricin on gastrointestinal tract and immune organs of mice with the dose of 1/5 LD50.In early days of intoxication,there was an obviously decrease in daffy weight and relative weight of thymus and spleen,fllowing the excretion of toxin,they had a trend of recovering to the normal state.Also,results of pathological section,scanning electron microscope and transmission electron microscope showed that ricin would induce a series of pathological reaction in intestines,meanwhile,the splenocytes displayed significant symptom of apoptosis and necrosis.

Cloning of PTD-NPY fusion gene and its secretory expression in Pichia pastoris / 生物工程学报

The PTD-NPY fusion gene derived from HIV-1 TAT protein transduction domain and rat neuropeptide Y was amplified by overlap extension PCR, digested and subcloned into yeast expression vector pPICZ alpha A to construct recombinant expression plasmid pPICZ alpha-PTD-NPY. The cloned PTD-NPY fusion gene was identified by PCR and restriction enzyme digestion and sequenced. The exact recombinant plasmid was linearized by Sac I and integrated by electrotransformation into the genome of Pichia pastoris GS115 cells. Then, these positive recombinant yeast cells were induced by 10 mL/L methanol to express soluble PTD-NPY fusion protein. After 120 h of methanol induction, the SDS-PAGE electrophoresis result indicated PTD-NPY fusion protein was efficiently secreted into the medium. Western blotting analysis proved that the expressed fusion protein had specific NPY binding activity. The successful expression of PTD-NPY fusion protein in Pichia pastoris provided basis for its further application study.