title: A new in vitro anti-tumor polypeptide isolated from Arca inflata.
abstract: 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 α-helix (45.2%), β-sheet (2.9%), β-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 µg/mL against A549, HT-29 and HepG2 cell lines, respectively. Therefore, J2-C3 might be developed as a potential anti-tumor agent.
authors: Biotechnological Institute of Chinese Materia Medica, Jinan University, Guangzhou 510632, China. tsly@jnu.edu.cn.
authors: Jian
authors: J
authors: Xu
authors: Zhiyan
authors: Z
authors: Chen
authors: Liyan
authors: L
authors: Song
authors: Lili
authors: L
authors: Chen
authors: Jianhua
authors: J
authors: Zhu
authors: Shuangshuang
authors: S
authors: Lv
authors: Rongmin
authors: R
authors: Yu
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D000596:Amino Acids; D000970:Antineoplastic Agents; D010455:Peptides