A New in Vitro Anti-Tumor Polypeptide Isolated from Arca inflata

作者:Xu, Jian; Chen, Zhiyan; Song, Liyan*; Chen, Lili; Zhu, Jianhua; Lv, Shuangshuang; Yu, Rongmin
来源:Marine Drugs, 2013, 11(12): 4773-4787.
DOI:10.3390/md11124773

摘要

A new in vitro anti-tumor polypeptide, coded as J2-C3, was isolated from Arca inflata Reeve and purified by diethyl-aminoethanol (DEAE)-sepharose Fast Flow anion exchange and phenyl sepharose CL-4B hydrophobic chromatography. J2-C3 was identified to be a homogeneous compound by native polyacrylamide gel electrophoresis (Native-PAGE). The purity of J2-C3 was over 99% in reversed phase-high performance liquid chromatography (RP-HPLC). The molecular weight was determined as 20,538.0 Da by electrospray-ionization mass spectrometry (ESI-MS/MS). J2-C3 was rich in Glx (Gln + Glu), Lys, and Asx (Asp + Asn) according to amino acid analysis. Four partial amino acid sequences of this peptide were determined as L/ISMEDVEESR, KNGMHSI/LDVNHDGR, AMKI/LI/LNPKKGI/LVPR and AMGAHKPPKGNEL/IGHR via MALDI-TOF/TOF-MS and de novo sequencing. Secondary structural analysis by CD spectroscopy revealed that J2-C3 had the -helix (45.2%), -sheet (2.9%), -turn (26.0%) and random coil (25.9%). The anti-tumor effect of J2-C3 against human tumor cells was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and the IC50 values of J2-C3 were 65.57, 93.33 and 122.95 mu g/mL against A549, HT-29 and HepG2 cell lines, respectively. Therefore, J2-C3 might be developed as a potential anti-tumor agent.