S-methyl-L-cysteine sulfoxide (SMCO) is a non-protein sulfur-containing amino acid with a variety of functions. There are few reports on the enzymes catalyzing the biosynthesis of SMCO from S-methyl-L-cysteine (SMC). In this study, the flavin-containing monooxygenase gene derived from Schizosaccharomyces pombe (spfmo) was heterologously expressed in Escherichia coli BL21(DE3) and the enzymatic properties of the expressed protein were analyzed. The optimum catalytic conditions of the recombinant SpFMO were 30 ℃ and pH 8.0, under which the enzyme activity reached 72.77 U/g. An appropriate amount of Mg²⁺ improved the enzyme activity. The enzyme kinetic analysis showed that the K_m and k_cat/K_m of SpFMO on the substrate SMC were 23.89 μmol/L and 61.71 L/(min·mmol), respectively. Under the optimal reaction conditions, the yield of SMCO synthesized from SMC catalyzed by SpFMO was 12.31% within 9 h. This study provides reference for the enzymatic synthesis of SMCO.
Schizosaccharomyces/genetics* ; Escherichia coli/metabolism* ; Recombinant Proteins/metabolism* ; Cysteine/biosynthesis* ; Mixed Function Oxygenases/metabolism* ; Schizosaccharomyces pombe Proteins/metabolism* ; Oxygenases/metabolism* ; Kinetics

Objective To compare and analyze the differences in CD8+naive,effector,memory,exhausted and regulatory T cells in order to investigate the impact of gender on the differentiation fate of CD8+T cells in the context of type 1 diabetes (T1D)based on female and male non-obese diabetic (NOD)mice and healthy Institute for Cancer Research (ICR)mice.Methods The frequencies and phenotypes of CD8+T cell differentiation subsets including naive T cells (TN),central memory T cells (TCM),effector T cells(TEFF),effector precursor T cells (TEP),exhausted T cells (TEX),precursor exhausted T cells (TPEX)and regulatory T cells (Tregs)in the spleen,pancreatic draining lymph nodes (pLN)and pancreas infiltrating lymphocytes (PIL)of male and female NOD mice were detected by flow cytometry.Results The frequencies of IFN-γ+,CD107a+and CCL5+CD8+TEFF in pLN and PIL of female NOD mice were significantly higher than those of male NOD mice.However,the frequencies of CD8+TN,CD8+TCM,CD8+TEX,CD8+TPEX and CD122+CD8+Tregs subsets in the spleen were significantly decreased.While there were no significant differences in the above CD8+T cell subsets except CD8+Tregs between female and male ICR mice. Conclusion Androgen may inhibit the differentiation of memory T cells into effector T cells and promote the exhaustion of effector T cells,leading to the difference in morbidity between the male and female mice.

Uncovering the risk factors of pulmonary hypertension and its mechanisms is crucial for the prevention and treatment of the disease.In the current study,we showed that experimental periodontitis,which was established by ligation of molars followed by orally smearing subgingival plaques from patients with periodontitis,exacerbated hypoxia-induced pulmonary hypertension in mice.Mechanistically,periodontitis dysregulated the pulmonary microbiota by promoting ectopic colonization and enrichment of oral bacteria in the lungs,contributing to pulmonary infiltration of interferon gamma positive(IFNγ+)T cells and aggravating the progression of pulmonary hypertension.In addition,we identified Prevotella zoogleoformans as the critical periodontitis-associated bacterium driving the exacerbation of pulmonary hypertension by periodontitis,and the exacerbation was potently ameliorated by both cervical lymph node excision and IFNγ neutralizing antibodies.Our study suggests a proof of concept that the combined prevention and treatment of periodontitis and pulmonary hypertension are necessary.

Objective To explore a best therapy regimen for conservative treatment of ectopic pregnancy.Methods Total of 124 cases of ectopic pregnancy underwent medicine therapy. They were divided into 4 groups: A group with MTX orly,B group with mifepristone only,C group with MTX and mifepristone comblnation,and D group with combined MTX, mifepristone and Traditional Chinese medicine (TCM). Results The curative rate was 80.65% ,61.29% ,87.10% and 90.32% in group A,group B,group C,and group D. The curative rate of group D is higher than other groups (P<0.05, P<0.01 ). Conclusion Combined MTX, mifepfistone and TCM has better effect on ectopic pregnany and has less side effects.