鸦胆子蛋白质组成分析及其酶解物细胞毒性研究

Protein composition analysis and cytotoxicity of gulbulin hydrolysates of Brucea javanica seeds

对鸦胆子进行蛋白质组成分析,并对其球蛋白酶解物细胞毒性进行研究。采用顺序抽提法提取鸦胆子清蛋白、球蛋白、醇溶蛋白和谷蛋白4类蛋白组分,并用凯氏定氮法进行定量;采用不同种蛋白酶水解鸦胆子球蛋白,MTT法考察其小分子量(≤3 k Da)酶解物对人乳腺癌MCF-7的细胞毒性。结果表明:鸦胆子总蛋白含量为17.47%,清蛋白、球蛋白、醇溶蛋白、谷蛋白和残渣蛋白分别占总蛋白含量的15.01%,8.11%,2.47%,44.92%,23.62%;球蛋白的胃蛋白酶酶解物(≤3 k Da)对人乳腺癌MCF-7具有显著的细胞毒性,且作用72 h后,IC_(50)为(6.52±0.01)mg·L^(-1)。鸦胆子蛋白质含量较为丰富,其多肽组分具有明确的体外细胞毒性,可进一步开发抗肿瘤活性成分。

To analyze the protein composition of Brucea javanica seeds and evaluate the cytotoxicity of its gulbulin hydrolysates. Four protein fractions of albumin, gulbulin, prolamin and glutelin were sequentially extracted and then quantified by Kjeldahl method. Different kinds of proteases were applied to hydrolyze B. javanica gulbulin, and MTT assay was used to evaluate the cytotoxicity of low molecular weight hydrolysates （ ≤3 kDa） on human breast cancer MCF-7 cell. The results showed that： the total protein content of B.javanica seeds was 17.47%, albumin, gulbulin, coxin, glutelin and residue protein accounted for 15.01%, 8.11%, 2.47%, 44. 92% and 23.62% of the total protein content, respectively. The hydrolysates （≤ 3 kDa） of B. javanica globulin produced by pepsin showed significant growth inhibitory activity on MCF-7 cells, and the IC50 value was（6.52 ±0.01 ） mg · L^-1 after 72 h of incubation. Protein was abundant in B. javanica seeds, and its peptides demonstrated specific cytotoxicity on MCF-7 cell line in vitro, suggesting antitumor active ingredient can be further generated from B. javanica seeds.