QUANTITATION OF THE INTERACTION OF THE IMMUNOSUPPRESSANT DEOXYSPERGUALIN AND ANALOGS WITH HSC70 AND HSP90
QUANTITATION OF THE INTERACTION OF THE IMMUNOSUPPRESSANT DEOXYSPERGUALIN AND ANALOGS WITH HSC70 AND HSP90
复制标题
DOI：
10.1021/bi00175a027
复制
发表时间：
1994-03-08
期刊：
影响因子：
2.9
通讯作者：
WALSH, CT
中科院分区：
文献类型：
--
作者：
NADEAU, K;NADLER, SG;WALSH, CT
脱氧精胍菌素（DSG）是一种精脒基、α-羟基甘氨酰、7-胍基庚酰肽模拟物，具有免疫抑制活性。在最近的一份报告，固定甲氧基DSG选择性地保留热休克蛋白Hsc 70的确认，我们在这里报告定量结合DSG和类似物Hsc 70和90-kDa的热休克蛋白Hsp 90。我们已经利用亲和毛细管电泳获得DSC和类似物的K-d值，并刺激Hsc 70的ATP酶活性以获得DSG的K-m值，这是可比的和确证的。DSG与Hsc 70结合的Kd值为4 μ M，DSG与Hsp 90结合的Kd值为5 μ M。两种活性类似物，甲氧基和甘氨酰DSG，以相似的亲和力结合。甘氨酰亚精胺和des（氨丙基）DSG，两种无活性的代谢产物，对Hsc 70和Hsp 90的亲和力大大降低。这些数据验证了这些新型免疫抑制剂与这些分子伴侣的结合，浓度范围为抗肿瘤活性剂量，并表明进一步表征Hsc 70和/或Hsp 90作为DSG的潜在靶点是必要的。
Deoxyspergualin (DSG), a spermidinyl, alpha-hydroxyglycyl, 7-guanidinoheptanoyl peptidomimetic, shows immunosuppressive activity. In confirmation of a recent report that immobilized methoxyDSG selectively retains the heat shock protein Hsc70, we report here quantitative binding of DSG and analogs to both Hsc70 and the 90-kDa heat shock protein Hsp90. We have utilized affinity capillary electrophoresis to obtain K-d values for DSC and analogs, and stimulation of the ATPase activity of Hsc70 to obtain K-m values for DSG, that are comparable and corroborative. K-d values are 4 mu M for DSG binding to Hsc70 and 5 mu M for DSG binding to Hsp90. Two active analogs, methoxy- and glycylDSG, bind with similar affinities. Glyoxylylspermidine and des(aminopropyl)DSG, two inactive metabolites, have much reduced affinity for Hsc70 and Hsp90. These data validate binding of these novel immunosuppressant agents to these molecular chaperones, at concentrations in the range of pharmacologically active doses, and indicate that further characterization of Hsc70 and/or Hsp90 as potential targets for DSG is warranted.