1.Expression and kinetic analysis of catalytic domain of protein tyrosine phosphatases SHP-1/SHP-2.
Yi MO ; Wei WANG ; Fangfang LIANG ; Guanyuan FU ; Hesheng JIANG ; Wayne ZHOU
Chinese Journal of Biotechnology 2009;25(2):274-278
In order to express and purify the catalytic domain of SHP-1/SHP-2 (named as D1C and D2C respectively) and determine their kinetics, the constructed D1C and D2C plasmids were transformed into Escherichia coli BL21 and the expression was induced with IPTG. The harvested cells were suspended in extraction buffer. After sonication, the solution was applied to HPLC and the results were confirmed by SDS-PAGE. The purified peptides were further subjected to kinetic specificity study using synthetic phosphotyrosine (pY) as substrate by malachite green method and analyzed by Lineweaver-Burk plot calculation. From this study, we found D1C and D2C were expressed successfully in soluble state in Escherichia coli BL21 and purified efficiently with HPLC system. The molecular weight of D1C was 34.6 kD, and its Michaelis constant (K(m)) was 2.04 mmol catalytic constant (K(cat)) was 44.98 s(-1), specific constant (K(cat)/K(m)) was 22.05 L/(mmol x s); the molecular weigh of D2C was 35.3 kD, and its Michaelis constant (K(m)) was 2.47 mmol, catalytic constant (K(cat)) was 27.45 s(-1), specific constant (K(cat)/K(m)) was L/(mmol x s). The enzyme activity of D1C is stronger than that of D2C.
Catalytic Domain
;
Chromatography, High Pressure Liquid
;
Escherichia coli
;
genetics
;
metabolism
;
Kinetics
;
Plasmids
;
Protein Tyrosine Phosphatase, Non-Receptor Type 11
;
genetics
;
metabolism
;
Protein Tyrosine Phosphatase, Non-Receptor Type 6
;
genetics
;
metabolism
;
Recombinant Proteins
;
genetics
;
metabolism
2.Advances in clinical application of quantitative susceptibility mapping in central nervous system.
Zhixue ZHANG ; Jun LIU ; Shunke ZHOU ; Zhifeng KOU
Journal of Central South University(Medical Sciences) 2015;40(7):816-819
Susceptibility weighted imaging (SWI) is a magnetic resonance technology with a high resolution, three-dimensional gradient echo and fully velocity compensated sequence. It is also sensitive to substance with different magnetisability. Based on the quantitative reconstruction of SWI, quantitative susceptibility mapping (QSM) has been used in monitoring the change of intravenous iron, calcium, microbleeds and oxygen content. This article summarizes principle of QSM and the latest progress of QSM application in the diseases of central nervous system.
Calcium
;
chemistry
;
Central Nervous System
;
Humans
;
Iron
;
chemistry
;
Magnetic Resonance Imaging
;
Oxygen
;
chemistry
3.Human Serum-derived Extracellular Vesicles Protect A549 from PM
Qiu Lian ZHOU ; Yu Zheng BAI ; Juan GAO ; Yi DUAN ; Yi Cheng LYU ; Long Fei GUAN ; Kenneth ELKIN ; Yu Ling XIE ; Zheng JIAO ; Hong Yun WANG
Biomedical and Environmental Sciences 2021;34(1):40-49
Objective:
Epidemiological studies reveal that exposure to fine particulate matter (aerodynamic diameter ≤ 2.5 μm, PM
Methods:
EVs were isolated from the serum of healthy subjects, quantified
Results:
PM
Conclusions
EVs treatment promotes cell survival and attenuates PM
A549 Cells
;
Air Pollutants/toxicity*
;
Apoptosis/drug effects*
;
Cell Survival/drug effects*
;
Extracellular Vesicles
;
Humans
;
Male
;
Middle Aged
;
Particulate Matter/toxicity*
;
Protective Agents/pharmacology*
;
Proto-Oncogene Proteins c-akt/metabolism*
;
Serum