Objective: To study a new purification method of Polysaccharide Peptide of Coriolus versicolor in affinity chromatography. Methods: Isotherm and kinetics in absorption and the optimal conditions of absorption and elution were studied through static experiments. The static absorption capacity q m and absorption constant K d were calculated according to Chase model. Results: q m =55.57mg/g wet resin, K d =5.312g/L, the dynamic absorption capacity is 43.1mg, polysaccharide/g wet resin and 10.3mg protein/g wet resin.Conclusion: Affinity chromatography can be used to purify PSP preliminarily.

Objective To assess the vaIue of speckle tracking imaging (STI) in quantifying the regional myocardial strain in systemic lupus erythematosus (SLE) group.Methods ① Sixty subjects were divided into SLE group and normal group.High frame rate two-dimensional images were recorded from the apical two-chamber view,long-axis view and four-chamber view of the left ventricle (LV).Peak systolic strain of each view of 18 segments were measured by automated functional imaging (AFI) software of 2-DSE.All parameters were compared between the two groups.② Twenty cases were randomly taken from the normal group.The same observer at different times and two observers measure the strain of left ventricular respectively.The results of the measurement between the two groups were compared with unpaired t test and its relevance was analyzed using Pearson's correlation analysis.ResultsLeft ventricular two-dimensional longitudinal strain gradually increased from the base to apex in the normal group.There were statistically differences between the apical segments and the basal,middle segments of every left ventricular wall (P＜0.05).The same wall segment time to peak myocardial systolic peak strain was consistent.Left ventricular two-dimensional longitudinal strain gradually increased from the base to apex in the SLE group,except for the anterio-septal and anterior wall [ (-18.7±4.2)％,(-16.3±9.4)％,(-18.1±10.5)％ vs (-19.0±9.0)％,(-18.6±7.9)％,(-17.7±1.4)％ ].There was no statistically significant difference between the apical segments and the basal,middle segments of every left ventricular wall(P＞0.05).All parameters of S were significantly higher in the normal group than those of the SLE group.The difference was statistically signoficant (P＜0.05).The time to peak systolic peak strain of every segments was not consistent.The results from the same observer at different times and peak systolic myocardial strain measurements by the two observers were correlated well(P＜0.01).Conclusion The myocardial function assessment by STI technology in the SLE patients is significantly different from that of the normal control:SLE patients with left ventricular myocardial damage can be manifested as reduced regional myocardial systolic peak strain.

Glutamate decarboxylase (GAD) can catalyze the decarboxylation of glutamate into γ-aminobutyrate (GABA) and is the only enzyme of GABA biosynthesis. Improving GAD activity and thermostability will be helpful for the highly efficient biosynthesis of GABA. According to the Ramachandran plot information of GAD 1407 three-dimensional structure from Lactobacillus brevis CGMCC No. 1306, we identified the unstable site K413 as the mutation target, constructed the mutant GAD by site-directed mutagenesis and measured the thermostability and activity of the wide type and mutant GAD. Mutant K413A led to a remarkably slower inactivation rate, and its half-life at 50 °C reached 105 min which was 2.1-fold higher than the wild type GAD1407. Moreover, mutant K413I exhibited 1.6-fold higher activity in comparison with the wide type GAD1407, although it had little improvement in thermostability of GAD. Ramachandran plot can be considered as a potential approach to increase GAD thermostability and activity.
Glutamate Decarboxylase ; metabolism ; Half-Life ; Industrial Microbiology ; Lactobacillus brevis ; enzymology ; Mutagenesis, Site-Directed ; Mutation ; Temperature