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The Effects of Treponema pallidum on Human Dendritic Cells
신종란,정기양,강진문,이태형,이민걸 연세대학교의과대학 2004 Yonsei medical journal Vol.45 No.SUP
Cell mediated immune responses play a prominent role in syphilis, which is caused by Treponema pallidum. The role of dendritic cells (DC) in the syphilitic infection is not well understood in human. In the present study, we studied interaction of T. pallidum with DC, generated from human peripheral blood mononuclear cells with GM-CSF and IL-4. After adding T. pallidum for 16 hours to immature DC at culture day 7, the change of surface antigens on DC was monitored by flow cytometry, the amount of IL-12 in culture supernatant of DC was measured by ELISA and T cell stimulatory capacity of DC was checked in mixed lymphocyte reaction (MLR). We have observed an efficient phagocytosis of T. pallidum by electron microscopy as early as 2 hours after addition of T. pallidum to DC. Interaction of DC with T. pallidum resulted in increased surface expression of CD83 which was proportionally increased according to the number of T. pallidum. Expressions of CD80, CD86 and HLA-DR on DC were slightly increased. The amount of IL-12 in the culture supernatant of DC was increased (1,099pg/ml) after the addition of T. pallidum. T. pallidum-infected DC also displayed enhanced T cell stimulatory capacity in MLR. As seen from the above, we observed phagocytosis of T. pallidum by DC as early as 2 hours after addition of T. pallidum to DC and found that T. pallidum can stimulate DC maturation which mean that DC modulate an protective immune response during T. pallidum infection.
Serratia marcescens Purine Nucleoside Phosphorylase의 생합성에 대한 글리옥실산의 대사적 역할
신종란,방선권,최병범 한국식품영양학회 1999 韓國食品營養學會誌 Vol.12 No.1
최소 배지에 여러 퓨린 분해 대사 산물을 첨가하여 배양시킨 Serratia marcescens ATTC 25419 세포 추출물에서 purine nucleoside phosphorylase(PNP)의 활성을 조사한 결과, 구아노신은 대조군에 비해 효소의 활성을 5∼15mM에서 60% 이상 감소시켰고, 이노신은 7∼15mM에서 30% 정도 감소시켰으나 0.1∼1mM에서 효소의 활성을 원래대로 회복시켰다. 아데노신, 히포크산틴 및 크산틴도 5∼15mM에서 효소의 활성을 40∼50%정도 감소시켰으나 0.1∼0.5mM에서는 원래대로 회복시켰다. 한편, 요산은 효소의 활성을 0.5mM에서 20% 증가시킨 반면 15mM에서 80% 감소시켰다. 요산의 최종 분해 산물인 글리옥실산도 효소의 활성을 0.5mM에서 20% 증가시킨 반면 3∼15mM에서 30∼50% 정도 감소시켰다. 5mM 농도의 이노신, 히포크산틴 및 요산을 동시에 첨가했을 경우 효소의 활성을 20% 정도 감소된 반면, 이노신과 요산, 세 퓨린 분해 대사 산물은 각각 0.5mM씩 동시 첨가했을 경우는 각각 22, 33%씩 증가시켰다. 이 결과는 낮은 농도 (0.5mM)의 글리옥실산이 S. marcescens purine nucleoside phosphorylase (PNP)의 활성을 증가시키고 고 농도의 글리옥실산은 감소시키는 것을 나타내기 때문에 퓨린 분해 대사 과정에서 글리옥실산이 PNP 생합성의 조절 역할을 하는 것으로 분석된다. The effects of purine catabolites in growth media on the Serratia marcescens purine nucleoside phosphorylase activity were examined. The enzyme activity was decreased above 60% by guanosine (5 to 15mM). The enzyme activity was decreased approximately by 30% in the presence of high concentrations of inosine (7∼15mM), but was not affected at low concentration of inosine (0.1∼1mM). The enzyme activity was decreased approximately by 40∼50% in the presence of high concentrations of adenosine, hypoxanthine, and xanthine (5∼15mM), but was not affected at low concentration of adenosine, hypoxanthine, and xanthine (0.1∼0.5mM). However, the enzyme activity was increased by 20% with low concentrations of uric acid (0.5mM), but was decreased by 80% with high concentrations of same purine catabolite (15mM). Also, the enzyme activity was increased by 20% with low concentration of glyoxylate (0.5mM), final degradative product of uric acid , but was decreased by 30∼50% with high concentrations of glyoxylate (3∼15mM). The enzyme activity was decreased approximately by 20% by the simultaneous addition of inosine, hypoxanthine and uric acid at 5mM each, whereas it was increased by 22 and 33% by the combination of inosine and uric acid, three purine catabolites at 0.5 mM, respectively. These data suggest that S. marcescens purine nucleoside phosphorylase is positively regulated by a glyoxylate concentration, and then may play a regulatory role in a purine catabolism.
Serratia marcescens Purine Nucleoside Phosphorylase의 정제와 특성
방선권,신종란,최병범 한국산업미생물학회 2000 한국미생물·생명공학회지 Vol.28 No.5
Serreatia marcescens ATCC 25419의 purine nucleoside phosphorylase(PNP)는 streptomycin sulfate treatment, Sephacryl S-200 gel filtration, AMP-agarose affinity chromatography 등의 방법으로 정제하였는데 최종 단계에서 9.8 unit/mg 이었으며 회수율은 7%이었고 49배 정제되었다. S. marcescens PNP는 native 분자량이 Sephadex G-150을 이용한 gel filtration 방법으로 168,000 달톤, SDS-PAGE에 의한 subunit의 분자량이 28,000 달톤이었으며, 동일한 subunit로 구성된 homer-hexamer 형태이었다. S. marcescens PNP의 inosine과 deoxyinosine에 대한 Km값은 각각 0.38, 1.20 mM이었다. S. marcescens PNP의 최적 pH와 최적온도는 각각 8.0, 50℃이었으며 또한, 50℃에서 PNP의 활성이 절반 정도 감소되는 것으로 보아 비교적 열에 안정한 단백질이었다. S. marcescens PNP는 Cu^2+에 의해 효소 활성이 완전히 억제되었다. Serratia marcescens purine nucleoside phosphorylase (PNP) was purified to homogeneity by streptomycin sulfate treatment, Sephacryl HR S-200 gel filtration chromatography and AMP-agarose affinity chromatography. The specific activity of the enzyme was increased 49-fold during purification with an overall yield of 7.0%. The molecular weight was 168 kD as estimated by Sephadex G-150 gel filtration chromatography. The S. marcescens enzyme was composed of six identical subunits with subunit molecular weight of 28 kD, as estimated by SDS-PAGE. The Km values of S. marcescens enzyme for inosine and deoxyinosine were 0.38 and 1.20 mM, respectively. The pH optimum was near 8.0, and the enzyme was relatively heat-stable protein. The enzyme was inactivated completely by 0.5 mM of Cu^2+.