Objective To construct expression vectors of calmodulin(CaM)mutants N2 and C2,and to express,purify,and identify the mutant proteins,in order to study the interactions between CaM and calcium channels. Methods The cDNA of N?lobe and C?lobe of CaM were used to prepare the cDNA of N2 and C2. Next,the recombinant cDNAs were cloned into a pGEX?6p?3 plasmid,and the recombinant plasmids were trans?ferred into E.coli BL21 cells. The transfected BL21 cells were stimulated with IPTG. The fusion proteins were extracted by ultrasonication and puri?fied by using GS?4B beads. Finally,protein activity was identified by the pull?down assay. Results Both the restriction digestion map and the DNA sequence identification results confirmed that the recombinant plasmids were successfully constructed. SDS?PAGE results showed high purity and concentration of N2 and C2 proteins. Their activities and binding abilities with the calcium channel fragment were confirmed by the pull?down assay.Conclusion In this study,expression vectors of N2 and C2 are successfully constructed,and physiologically active N2 and C2 CaM mutant proteins are obtained.

Thirteen compounds were isolated from the stem bark of Bombax ceiba L. by silica gel, and Sephadex LH-20 column chromatography. Their structures were identified by spectroscopic analysis as: lupeol(1), lupeone(2), betulinic acid(3), zeorin(4), oleanolic acid(5), 3-oxooleanolic acid(6), cleomiscosin A(7), (±)-lyoniresinol(8), desmosterol(9), stigma-3, 6-dione(10), (+)-lasiodiploidin(11), aurantiamide acetate(12), and(2S, 3S, 4R, 10E)-2-［(2R)-2-hydroxytetracosanoylamino］-10-octadecene-1, 3, 4-triol(13). Among them, compounds 3, 4, 6, 7-13 were isolated from this plant for the first time.

Objective:To explore the expression and predictive value of serum CD36 level in cardio-vascular risk in patients with rheumatoid arthritis (RA) and to provide a new theoretical basis for clinical iden-tification and prediction of patients at moderate and high cardiovascular risk in RA patients.Methods:Eighty-four RA patients hospitalized to the Department of Rheumatology and Immunology of the second hospital of Lanzhou University in Gansu Province were selected as the study subjects, and 34 healthy people were selected as the controls. All RA patients were divided into low cardiovascular risk groups and medium and high cardiovascular risk groups according to prediction for ASCVD risk in China (China-PAR) cardiovascular risk assessment. At the same time, they were tested for serological indicators at admission. Statistical Product and Service Solutions (SPSS)) 26.0 software was used for the statistical data analysis. T-test and nonparametric test were used for comparison of the measurement data. The Chi-square test and Fisher's exact test were used for the comparison of classified data. Variables with P<0.05 in univariate analysis were included into the Logistic regression model. Results:Compared with the healthy control group, the number of patients with medium and high cardiovascular risk in RA[8 cases (23.5)% and 38 cases (45.2)%, χ2=4.80, P=0.029] was significantly higher and was negatively correlated with serum CD36 ( r=-0.27, P<0.05). Logistic regression analysis showed that age [ OR(95% CI)=1.654(1.157, 2.365), P=0.006] and diastolic blood pressure [ OR(95% CI)=1.225(1.040, 1.442) , P=0.015] were independent risk factors for medium and high cardiovascular risk in RA patients, and serum CD36 level [ OR(95% CI)=0.569(0.352, 0.922) , P=0.022] was the protective factor of medium and high cardiovascular risk in RA patients according to the results of Logistic regression analysis. The area under the receiver operating characteristic (ROC) area under the curve (AUC) was 0.691, the cut-off value was 4.27 pg/ml, and the sensitivity and specificity were 89.7% and 41.0% respectively. Conclusion:The serum CD36 level decreases with the increase of cardiovascular risk in RA patients. A higher serum CD36 level is a protective factor of cardiovascular risk in RA patients, and CD36 has a certain predictive value for cardiovascular risk in RA patients and is a potential predictor.