Identification and characterization of topoisomerase II inhibitory peptides from soy protein hydrolysates.
Identification and characterization of topoisomerase II inhibitory peptides from soy protein hydrolysates.
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DOI：
10.1021/jf8005195
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发表时间：
2008-07
影响因子：
6.1
通讯作者：
Wenyi Wang;S. Rupasinghe;M. Schuler;E. González de Mejía
中科院分区：
文献类型：
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作者：
Wenyi Wang;S. Rupasinghe;M. Schuler;E. González de Mejía
拓扑异构酶是几种抗癌药物的靶标，因为它们的抑制阻碍了癌发生中的细胞增殖和分化过程。由于膳食蛋白中肽的抑制活性信息非常有限，本研究的目的是采用免疫共沉淀法在一个步骤中鉴定大豆蛋白水解物中的抑制肽，并研究其与拓扑异构酶II的分子相互作用。为此，用胃蛋白酶和胰酶对大豆蛋白分离物进行模拟胃肠道消化，并将人拓扑异构酶II抑制肽免疫共沉淀并在CapLC-Micromass Q-TOF Ultima API系统上鉴定。使用三种合成肽FEITPEKNPQ、IETWNPNNKP和VFDGEL（IC 50值分别为2.4、4.0和7.9 mM）证实了来自大豆分离物的这些肽对拓扑异构酶II的抑制活性。通过分子对接评估的这些肽的分子相互作用揭示了与拓扑异构酶II C-末端结构域（CTD）的相互作用能（-186至-398 kcal/mol）小于ATP酶结构域的相互作用能（-169至-357 kcal/mol），并且与我们的实验IC 50值良好相关（R（2）= 0.99）。总之，从体外胃肠道酶消化大豆蛋白释放的三种肽通过与CTD结构域的活性位点结合来抑制人拓扑异构酶II活性。
Topoisomerases are targets of several anticancer agents because their inhibition impedes the processes of cell proliferation and differentiation in carcinogenesis. With very limited information available on the inhibitory activities of peptides derived from dietary proteins, the objectives of this study were to employ co-immunoprecipitation to identify inhibitory peptides in soy protein hydrolysates in a single step and to investigate their molecular interactions with topoisomerase II. For this, soy protein isolates were subjected to simulated gastrointestinal digestion with pepsin and pancreatin, and the human topoisomerase II inhibitory peptides were co-immunoprecipitated and identified on a CapLC- Micromass Q-TOF Ultima API system. The inhibitory activity of these peptides from soy isolates toward topoisomerase II was confirmed using three synthetic peptides, FEITPEKNPQ, IETWNPNNKP,and VFDGEL, which have IC 50 values of 2.4, 4.0, and 7.9 mM, respectively. The molecular interactions of these peptides evaluated by molecular docking revealed interaction energies with the topoisomerase II C-terminal domain (CTD) (-186 to -398 kcal/mol) that were smaller than for the ATPase domain (-169 to -357 kcal/mol) and that correlated well with our experimental IC 50 values ( R (2) = 0.99). In conclusion, three peptides released from in vitro gastrointestinal enzyme digestion of soy proteins inhibited human topoisomerase II activity through binding to the active site of the CTD domain.