Putrescine activated S-adenosylmethionine decarboxylase from Trypanosoma brucei brucei.
Putrescine activated S-adenosylmethionine decarboxylase from Trypanosoma brucei brucei.
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腐胺激活布氏锥虫的 S-腺苷甲硫氨酸脱羧酶。
DOI：
10.1007/bf00230410
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发表时间：
1992
影响因子：
4.3
通讯作者：
Pegg,AE
中科院分区：
文献类型：
--
作者：
Tekwani,BL;Bacchi,CJ;Pegg,AE
布氏锥虫（Trypanosoma brucei）含有一种能被腐胺强烈激活的S-腺苷-L-甲硫氨酸脱羧酶（S-adenosyl-L-methionine decarboxylase，S-MetDC）。尸胺和1，3-二氨基丙烷也能在较小程度上激活该酶。亚精胺和精胺对酶的基础活性没有影响。然而，他们干扰腐胺激活的锥虫cytomalMetDC。锥虫酶不能用抗人β-MetDC的抗血清沉淀。在NaCNBH_4存在下，通过与35 S-脱羧的Trypanosomal MetDC酶亚基反应来标记Trypanosomal MetDC酶亚基，并在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳上发现其分子量为34 kDa。该亚基在储存时容易降解为分子量为26 kDa的形式。通过在特异性β-MetDC抑制剂[甲基乙二醛双（鸟苷酰腙（MGBG），一种可逆抑制剂，或5′-脱氧-5 ′-[（2-肼基乙基）甲氨基]腺苷（MHZEA），一种不可逆灭活剂]存在下阻止35 S-脱羧S-腺苷甲硫氨酸（β-Met）结合，证实了该方法标记β-MetDC的特异性。与人β-MetDC相比，锥虫酶显示出与MGBG-琼脂糖柱的较弱结合，并且对MGBG及其同源物乙基乙二醛双（鸟苷酰腙）（EGBG）的抑制作用也显著较不敏感。因此，锥虫的MetDC显着不同于其哺乳动物和细菌的对应物，因此可以开发作为锥虫的化疗的特定目标。
Trypanosoma brucei bruceicontained a S-adenosyl-L-methionine decarboxylase (AdoMetDC) strongly activated by putrescine. The enzyme was also activated to a lesser extent by cadaverine and 1,3-diaminopropane. Spermidine and spermine had no effect on basal activity of the enzyme. However, they interfered with putrescine activation of trypanosomal AdoMetDC. The trypanosomal enzyme could not be precipitated with antiserum against human AdoMetDC. The trypanosomal AdoMetDC enzyme subunit was labeled by reaction with35S-decarboxylated AdoMet in the presence of NaCNBH4, and found to have a molecular weight of 34 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The subunit was readily degraded on storage to a form with a molecular weight of 26 kDa. The specificity of labeling of AdoMetDC by this procedure was confirmed by the prevention of35S-decarboxylated S-adenosylmethionine (AdoMet) binding in the presence of specific AdoMetDC inhibitors [either methylglyoxal bis(guanylhydrazone (MGBG), a reversible inhibitor, or 5′-deoxy-5′-[(2-hydrazinoethyl)methylamino]adenosine (MHZEA), an irreversible inactivator]. As compared to human AdoMetDC, the trypanosomal enzyme showed weaker binding to a column of MGBG-Sepharose and also was significantly less sensitive to inhibition by MGBG and its congener ethylglyoxal bis(guanylhydrazone) (EGBG). Thus, the trypanosomal AdoMetDC differs significantly from its mammalian and bacterial counterparts and may therefore be exploited as a specific target for chemotherapy of trypanosomiasis.